# Results from The COPAINS Pilot Survey: four new brown dwarfs and a high
companion detection rate for accelerating stars

M. Bonavita1,2,3, C. Fontanive4, R. Gratton3, K. Mužić5, S. Desidera3, D.
Mesa3, B. Biller2, A. Scholz6, A. Sozzetti7, V. Squicciarini3,8
1School of Physical Sciences, The Open University, Walton Hall, Milton Keynes,
MK7 6AA
2SUPA, Institute for Astronomy, University of Edinburgh, Blackford Hill,
Edinburgh EH9 3HJ, UK
3INAF Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35121
Padova, ITALY
4Center for Space and Habitability, University of Bern, Bern 3012, Switzerland
5CENTRA, Faculdade de Ciências, Universidade de Lisboa, Ed. C8, Campo Grande,
P-1749-016 Lisboa, Portugal
6SUPA, School of Physics & Astronomy, University of St Andrews, North Haugh,
St Andrews, KY16 9SS, UK
7INAF - Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025, Pino
Torinese, Italy
8Department of Physics and Astronomy Galileo Galilei, University of Padova,
Via dell’Osservatorio 3, I-35122 Padova, Italy E-mail:
<EMAIL_ADDRESS>
(Accepted 2022 April 25. Received 2022 April 21; in original form 2022 April
08)

###### Abstract

The last decade of direct imaging (DI) searches for sub-stellar companions has
uncovered a widely diverse sample that challenges the current formation
models, while highlighting the intrinsically low occurrence rate of wide
companions, especially at the lower end of the mass distribution. These
results clearly show how blind surveys, crucial to constrain the underlying
planet and sub-stellar companion population, are not an efficient way to
increase the sample of DI companions. It is therefore becoming clear that
efficient target selection methods are essential to ensure a larger number of
detections. We present the results of the COPAINS Survey conducted with
SPHERE/VLT, searching for sub-stellar companions to stars showing significant
proper motion differences ($\Delta\mu$) between different astrometric
catalogues. We observed twenty-five stars and detected ten companions,
including four new brown dwarfs: HIP 21152 B, HIP 29724 B, HD 60584 B and HIP
63734 B. Our results clearly demonstrates how astrometric signatures, in the
past only giving access to stellar companions, can now thanks to Gaia reveal
companions well in the sub-stellar regime. We also introduce FORECAST (Finely
Optimised REtrieval of Companions of Accelerating STars), a tool which allows
to check the agreement between position and mass of the detected companions
with the measured $\Delta\mu$. Given the agreement between the values of the
masses of the new sub-stellar companions from the photometry with the model-
independent ones obtained with FORECAST, the results of COPAINS represent a
significant increase of the number of potential benchmarks for brown dwarf and
planet formation and evolution theories.

###### keywords:

stars: brown dwarfs, stars: low mass, (stars) binaries: visual,
instrumentation: adaptive optics, astrometry

††pagerange: Results from The COPAINS Pilot Survey: four new brown dwarfs and
a high companion detection rate for accelerating stars –Acknowledgements

##  1 Introduction

Direct imaging (DI) is the only detection method that provides observations of
an exoplanet or brown dwarf (BD) itself, as it captures the thermal emission
of self-luminous companions. With the unique opportunity to obtain photometric
and spectroscopic observations of substellar objects, this detection method
allows for a direct probe of cold companions atmospheres. DI is also necessary
to study the outer regions of planetary systems, that cannot be probed by
other detection methods.
Despite the remarkable efforts that have been invested in the development of
new observing technologies and image processing techniques, and a steady
increase in the census of wide-orbit companions, only a handful of systems
below the deuterium-burning limit have been uncovered around stars in DI
programs, and the occurrences of wide companions appear to be intrinsically
low (Biller et al., 2007, 2013; Lafrenière et al., 2007; Nielsen & Close,
2010; Vigan et al., 2012, 2017, 2021; Rameau et al., 2013; Galicher et al.,
2016a; Nielsen et al., 2019). In order to empirically constrain the formation,
evolution, and atmospheric properties of both isolated and bound sub-stellar
companions, we need to uncover a substantial population of these objects, and
measure their fundamental properties, such as the effective temperature and
mass. However, even when a comprehensive view and an extensive spectro-
photometric characterisation is possible, imaging surveys still only provide
measurements of an object’s luminosity. Mass estimates for imaged planets and
brown dwarfs therefore rely entirely on evolutionary models, which currently
carry high uncertainties, particularly at young to intermediate ages. An
independent determination of masses from dynamical arguments is therefore
crucial to overcome the large uncertainties introduced by evolutionary models,
and in turn refine the theories. Furthermore, a sample of benchmark objects
should ideally span a wide range of properties (e.g., spectral types, masses,
ages). As direct imaging is more amenable to very young systems, where low-
mass companions are still bright, the majority of the scarce sample of such
benchmark objects in the planetary regime orbit relatively young stars (few
tens to hundred Myr). On the contrary, most brown dwarf companions with well-
defined dynamical masses orbit older hosts with field ages of several Gyrs
(see Fig. 1). As known bound sub-stellar companions are even rarer in
associations such as Hyades ($\sim$650 Myr Martín et al., 2018), the
intermediate age regime remains relatively unexplored, and theoretical models
are hence particularly poorly constrained at these ages. Our understanding of
the origins and atmospheres of these objects thus remains severely limited by
the small number of known systems. In particular, the sparse sample of
directly-imaged companions show a large diversity of spectro-photometric
characteristics and orbital configurations, and remain challenging to grasp as
populations (Bowler, 2016). Larger numbers of detections are hence essential
to enable a better characterisation and understanding of the wide-orbit
companion population, and obtain a clearer picture of their formation
patterns.
In Fontanive et al. (2019), we presented a new tool COPAINS (Code for Orbital
Parametrisation of Astrometrically Inferred New Systems), developed to
identify previously undiscovered companions detectable via DI, based on
changes in stellar proper motions across multiple astrometric catalogues. A
significant proper motion difference ($\Delta\mu$) between two catalogues for
a given star is a good indication of the presence of a perturbing body. For
systems showing significant differences between proper motions measured over a
long time baseline (e.g., Tycho-2, or Tycho GaiaAstrometric Solution - TGAS;
Høg et al. 2000; Michalik et al. 2015), and catalogues that provide short-term
proper motions (e.g., Hipparcos, GaiaDR2; ESA 1997; Gaia Collaboration et al.
2018), the tool allows for the computation of secondary mass and separation
pairs compatible with the observed trend, marginalised over all possible
orbital phases and eccentricities. The resulting solutions are based entirely
on dynamical arguments, although a dependence on the adopted (usually model-
derived) stellar mass remains in the obtained secondary masses. Compared to
the expected sensitivity of an imaging instrument, these predictions can then
be used to select the most promising targets for DI searches of low-mass
companions.
The use of such informed selection processes had already proven to be
effective in the stellar regime (Makarov & Kaplan, 2005; Tokovinin et al.,
2013; Bowler et al., 2021; Steiger et al., 2021), and recently led to the
discovery of new brown dwarf companions based on the astrometric signatures
induced on their host stars (Currie et al., 2020; Chilcote et al., 2021). Such
astrometric systems are particularly valuable, as the combination of relative
astrometry from DI information with absolute astrometry from the primary’s
astrometric signature offers a remarkable opportunity to refine orbital
constraints and measure dynamical masses (Calissendorff & Janson, 2018;
Snellen & Brown, 2018; Brandt et al., 2019; Dupuy et al., 2019; Grandjean et
al., 2019; Maire et al., 2020; Nielsen et al., 2020; Drimmel et al., 2021).
Precise orbital elements for the population of wide-orbit companions can
provide key insights into formation mechanisms (e.g., Bowler et al., 2020).
Furthermore, model-independent mass measurements for brown dwarfs and giant
planets are especially important to bypass the use of mass estimates from
theoretical models, which typically carry large uncertainties, both due to the
difficulties of determining system ages, and to the systematic uncertainties
of the evolutionary and atmosphere models which are particularly pronounced at
the lowest masses and youngest ages. Increasing the pool of systems amenable
to dynamical mass measurements will therefore be essential to help calibrate
theoretical models for substellar objects.
In this paper, we present the results of a pilot survey conducted with the
SPHERE instrument (Beuzit et al., 2019), an extreme adaptive optics facility
at the ESO’s Very Large Telescope (VLT), which employed the COPAINS tool for
informed target selection. We describe the sample and selection method in
Section 2. The observations and data reduction are presented in Section 3. The
survey results are reported in Section 4 and discussed in Section 5.

##  2 Sample Properties

###  2.1 Target Selection

####  2.1.1 Initial Target List

To select targets for DI campaigns, we searched different catalogues
containing proper motions, using as an input a list of known, relatively
young, sources, from which the targets protected by the SPHERE Guaranteed Time
Observations (GTO) were removed. For the sources with both long- and short-
term proper motion information, we first selected stars showing a difference
larger than $3\sigma$ between two catalogues, in either of the proper motion
components. The data presented here were obtained during three ESO periods
(P100, P102, and P104)111ESO programme IDs 0100.C-0646, 0102.C-0506,
0104.C-0965 , with several differences in target selection procedure, as a
result of the different $Gaia$ data releases available at the time of each
selection. The relevant information about the two initial selections are
listed here.

Selection 1 (P100 and P102)

  * •

Input list: An extensive compilation of about 900 nearby young stars (Desidera
et al., 2015).

  * •

Long-term proper motion catalogue: Tycho-2 (Høg et al., 2000), with a proper
motion baseline of $\sim$100 yr.

  * •

Short-term proper motion catalogue: The Tycho-GaiaAstrometric Solution (TGAS;
Michalik et al., 2015), part of $Gaia$ DR1 (Gaia Collaboration et al., 2016),
with a proper motion baseline of $\sim$25 yr.

Selection 2 (P104)

  * •

Input list: The same compilation as above (Desidera et al., 2015),
complemented by bona-fide members of nearby young moving groups (Gagné et al.,
2018; Gagné & Faherty, 2018). In total, there are about 2200 unique objects in
this input list.

  * •

Long-term proper motion catalogue: TGAS, with a proper motion baseline of
$\sim$25 yr.

  * •

Short-term proper motion catalogue: $Gaia$ DR2 (Gaia Collaboration et al.,
2018), with a proper motion baseline of $\sim$1.5 yr.

Following the selection of these so-called $\Delta\mu$ candidates, stars with
known companions from visual and/or radial velocity observations were removed
from the list. A star was removed if satisfying any of the following criteria:

  * •

Multiplicity flag (MultiFlag) equal to C or O in the Hipparcos catalogue (ESA,
1997);

  * •

Star appears in the Catalog of Components of Double & Multiple stars (CCDM;
Dommanget & Nys 2002);

  * •

Star appears in The ninth catalogue of spectroscopic binary orbits
(S${}_{B}^{9}$; Pourbaix et al. 2004);

  * •

Star has a sub-stellar companion listed in The Extrasolar Planets
Encyclopaedia222http://exoplanet.eu/;

  * •

A suffix in the name of the star indicating that it is part of a binary
system, or an unresolved binary (e.g. A, B, AB).

  * •

For the Selection 2, we also excluded stars with another source closer than
$5^{\prime}$ on the sky, and sharing the same parallax (within 3$\sigma$), in
order to exclude obvious stellar binaries from the survey and correctly focus
on sub-stellar companions. For this, we only used the sources with a
relatively small parallax uncertainties ($\varpi$/ $\sigma_{\varpi}<0.2$).

Figure 1: Examples of the solutions computed with COPAINS for the observed
astrometric trends of one target selected through the Selection 1 process
(using Tycho-2 and TGAS; left) and one target from the Selection 2 process
(using TGAS and GaiaDR2; right). The solid black lines corresponds to the
median curves of solutions, and the dark and light shaded areas represent the
1 and 2-$\sigma$ confidence intervals, respectively. The dashed grey lines
show the expected detection limit used for the survey selection, computed as
detailed in the text.

####  2.1.2 COPAINS Selection

After removing known binaries as detailed above, we further retained only the
targets for which the COPAINS tool (Fontanive et al., 2019) returned that the
objects causing the observed astrometric trends could be sub-stellar, if in
the parameter space detectable with SPHERE (i.e., within the instrument field-
of-view and above the expected sensitivity of observations).
COPAINS provides a good indication of the region of the parameter space in
which a hidden companion responsible for an observed astrometric offset may
be. Based on the formalism from Makarov & Kaplan (2005), the approach assumes
that long-term proper motion measurements are representative of a system’s
centre-of-mass motion, and that short-term measurements correspond to the
instantaneous reflex motion of the host star. For a measured $\Delta\mu$
value, the code allows us to evaluate the possible companion mass and
separation pairs compatible with the astrometric data, for a given distance,
stellar mass (see Section 2.3), and eccentricity distribution, while assuming
face-on orbital inclinations (see Fontanive et al., 2019 for details). We
adopted a Gaussian eccentricity distribution centred around $e$=0 with a width
of 0.3 (Bonavita et al., 2013), and the astrometric catalogues listed above
were used as long- and short-term proper motion values.
Figure 1 shows examples of the resulting trends computed with COPAINS for one
target from P100 (left) and one target from P104 (right). In each case, the
estimated solutions were compared to the expected sensitivity limit of SPHERE-
IFS, shown as a red solid line in Figure 1. The IFS limits were obtained
following the approach described by Mesa et al. (2021) and converted to
minimum mass limits using the models from Baraffe et al. (2015) and the values
of the age and stellar mass available at the time of the selection. Only
promising targets, where the intersection of the detection limits and computed
regions suggested possible sub-stellar companions detectable in our survey,
were kept for the final sample, based on a visual analysis of the obtained
plots. Finally, only the targets not previously observed with SPHERE, and
observable in the relevant ESO period were kept. The final target list
consisting of 25 stars observed with SPHERE is given is Table 1, while Table 2
lists the values of the proper motions from Tycho-II, TGAS, Gaia DR2 and EDR3
and the resulting $\Delta\mu$.

###  2.2 Stellar Ages

A full revision of the stellar ages was performed for all the targets
following the approaches described in Desidera et al. (2015) and Desidera et
al. (2021), considering a variety of indicators and also performing a check
for membership to groups using the BANYAN $\Sigma$ on-line tool
333http://www.exoplanetes.umontreal.ca/banyan/banyansigma.php (Gagné et al.,
2018). Most of the targets were found to be field objects, while still
compatible with a relatively young age, or stars with ambiguous membership. In
these cases, we considered indirect age indicators such as the equivalent
width of 6708Å Lithium doublet, rotation period, X-ray emission, chromospheric
activity, taking as reference the empirical sequences of members of groups and
clusters (e.g., Desidera et al., 2015) and isochrone fitting. Several of our
targets have ages between Hyades and Pleiades. In this range, we took
advantage of the recently derived rotation sequence for Group X at an age of
300 Myr (Messina et al., 2022). When applicable, we considered the age
indicators for physical companions outside the SPHERE field of view and, for
close binaries, we deblended photometric colors for binarity, to improve the
reliability of the derived ages. For the few target found to be belonging to
young moving groups, we adopted the values of the ages presented in Bonavita
et al. (2016) and Desidera et al. (2021), mostly based on Bell et al. (2015).
All targets were found to be younger than 1 Gyr, except for GJ 3346 for which
the age is likely to be closer to 5 Gyr as discussed in detail in Bonavita et
al. (2020). The age determination process for each target is discussed in
Appendix A.

###  2.3 Stellar Masses

The masses for all the stars in the sample were also revised, using the
Manifold Age Determination for Young Stars (madys, Squicciarini & Bonavita in
preparation; see Squicciarini et al., 2021, for a description of the tool) and
the updated values of the stellar ages. Madys retrieved and cross-matched
photometry from Gaia EDR3 (Gaia Collaboration et al., 2021) and 2MASS
(Skrutskie et al., 2006) for all our targets and then applied a correction for
interstellar extinction by integrating along the line of sight the 3D
extinction map by (Leike et al., 2020); the derived A(G) were turned into the
photometric band of interest using a total-to-selective absorption ratio
$R$=3.16 and extinction coefficients $A_{\lambda}$ from Wang & Chen (2019).
The derived absolute magnitudes were then compared with a grid of isochrones
with an age range based on the minimum and maximum age values included in
Table 1 to yield a mass estimate. Madys can use several available grids, but
in this instance the PARSEC isochrones (Marigo et al., 2017) were used, due to
their large dynamical range spanning the entire stellar regime. A constant
solar metallicity, appropriate for most nearby star-forming regions, was
assumed (D’Orazi et al., 2011) for all targets except for HIP 21152 and HIP
21317, for which we assumed [Fe/H]=+0.13 based on their membership to the
Hyades (see Appendix A for details). For each star, a sample of mass estimates
was constructed by computing the best-fit mass at different ages within the
given age range; its median was taken as the final mass estimate, while the
reported errors represent the 16th and the 84 percentile; photometric
uncertainties were naturally propagated on the final result via a Monte Carlo
approach, i.e. by randomly varying, in a Gaussian fashion, photometric data
according to their uncertainties while building the sample of mass estimates.

Figure 2: IFS detection limits expressed in contrast (left) and minimum
companion mass (right) vs projected separation, for all the targets in our
sample. The dashed vertical line marks the coronographic radius. Note that
objects with multiple epochs will appear more than once. The COND models
(Baraffe et al., 2003) were used for the magnitude to mass conversion, using
the adopted age from Table 1.

##  3 Observations and data reduction

All observations were performed with VLT/SPHERE (Beuzit et al., 2019) with the
two Near Infra-Red (NIR) subsystems, IFS (Claudi et al., 2008) and IRDIS
(Dohlen et al., 2008) observing in parallel (IRDIFS Mode), with IRDIS in dual-
band imaging mode (DBI; Vigan et al., 2010). For all targets we used the
IRDIFS-EXT mode, which enables covering the $Y$-, $J$-, $H$-, and $K$-band in
a single observation, which is meant to provide a high-level of spectral
content for subsequent analyses.
A summary of the observing parameters and conditions is given in Table 3. The
observing sequence adopted was similar to those designed for the SHINE
Guaranteed time survey (see e.g. Chauvin et al., 2017) and consisted of:

  * •

One PSF sub-sequence composed of a series of off-axis unsaturated images
obtained with an offset of $\sim$0.4′′ relative to the coronagraph center
(produced by the Tip-Tilt mirror). A neutral density filter was used to avoid
saturation444www.eso.org/sci/facilities/paranal/instruments/sphere/inst/filters.html
and the AO visible tip-tilt and high-order loops were closed to obtain a
diffraction-limited PSF.

  * •

A star center coronagraphic observation with four symmetric satellite spots,
created by introducing a periodic modulation on the deformable mirror (see
Langlois et al., 2013, for details), in order to enable an accurate
determination of the star position behind the coronagraphic mask for the
following deep coronagraphic sequence.

  * •

The deep coronagraphic sub-sequence, for which we used here the smallest
apodized Lyot coronagraph (ALC-YH-S) with a focal-plane mask of 185 mas in
diameter.

  * •

A new star center sequence, a new PSF registration, as well as a short sky
observing sequence for fine correction of the hot pixel variation during the
night.

IRDIS and IFS data sets were reduced using the SPHERE Data Reduction and
Handling (DRH) automated pipeline (Pavlov et al., 2008) at the SPHERE Data
Center (SPHERE-DC, see Delorme et al., 2017) to correct for each data cube for
bad pixels, dark current, flat field and sky background. After combining all
data cubes with an adequate calculation of the parallactic angle for each
individual frame of the deep coronagraphic sequence, all frames are shifted at
the position of the stellar centroid calculated from the initial star center
position. In order to calibrate the IRDIS and IFS data sets on sky, we used
images of the astrometric reference field 47 Tuc observed with SPHERE at a
date close to our observations. The plate scale and true north values used are
based on the long-term analysis of the GTO astrometric calibration described
by Maire et al. (2016).

###  3.1 Detection Limits

In order to evaluate our sensitivity to stellar companions, we determined
detection limits for point sources. We used the standard procedure to derive
detection limits outside the coronagraphic field masks that makes use of the
SPECAL software as described in Galicher et al. (2018) and used in the F150
survey (Langlois et al., 2021). The detection limits considered here were
obtained using the Template Locally Optimised Combination of Images (TLOCI
Marois et al., 2014) for IRDIS and the ASDI-PCA (Angular Spectral Differential
Imaging with PCA Galicher et al., 2018) for IFS.
Contrast limits for the individual data sets are shown in the left panel of
Fig. 2 and reported in Table 4. The corresponding values of the minimum
companion mass limits, obtained using the evolutionary models from Baraffe et
al. (2015) for the magnitude to mass conversion, are shown in the right panel
Fig. 2.
The achieved average limits appear to be significantly worse than the average
of the expected limits (dashed-dotted line in Fig. 2) used for the target
selection. This is most likely due to the fact that, since our program was
executed in service mode and as filler, most of our targets were observed in
sub-optimal conditions and with very small field rotation, with a strong
negative effect on the quality of the high contrast imaging performances,
especially at short separations. This is also confirmed by the fact that the
average limit achieved for the first 150 targets of the SHINE survey (gray
solid line, from Vigan et al. (2021)), where all target were observed in the
best possible conditions, is instead much better than both the measured and
estimated COPAINS limits.

Figure 3: Detected candidate companions in the IFS (top 2 rows) and IRDIS
(bottom row) field of view. The red circle marks the position of the
candidate.

##  4 Results

We detected a total of 14 candidate companions, 4 of which were found to be
background sources thanks to additional epochs available in the literature or
obtained in our program (HIP 63862, HD 57852, HIP 33690). The 10 co-moving
companions are shown in Fig. 3. Eight of the co-moving companions have
separations below 0.9 arcseconds, and are therefore in the IFS field of view,
while the remaining 2 were only observed with IRDIS. Five are new discoveries,
including a white dwarf companion at $\sim 3.6^{\prime\prime}$ from GJ 3346
(already presented in Bonavita et al. (2020)) and four new sub-stellar
companions: HIP 21152 B555HIP 21152 B was independently discovered as part of
two other surveys targeting accelerating stars, as detailed in Kuzuhara et al.
(2022) and Franson et al. 2022 (in preparation). Both works include an in-
depth characterisation of the system, the latter also including a full
spectral and orbital analysis combining all available data sets. , HIP 29724
B, HD 60584 B and HIP 63734 B. Their properties are discussed in details in
Sec. 4.5, 4.6 and 4.7.

###  4.1 SPHERE astrometry and photometry

The astrometry and photometry measurements from all our SPHERE observations,
are listed in Table 5. For each epoch we report the projected separation and
position angle, and the contrast (expressed as apparent magnitude difference)
in the IFS $Y$ and $J$ filters, as well as the IRDIS $K_{1}$ and $K_{2}$ for
the IRDIFS-EXT observations666see
www.eso.org/sci/facilities/paranal/instruments/sphere/inst/filters.html for a
full description of the SPHERE filters.. The probability that the source is a
background star, evaluated as described in Sec. 4.2, is also listed.

Figure 4: Common proper motion analysis of all our candidate companions with
multiple epochs (reported in Table 7). The blue line shows the motion of a
background object relative to the target, based on the EDR3 parallax and
proper motion of the primary over the same time frame. In all panels, the
filled circles show the measured separation and position angle of the
companions at each epoch, colour coded as explained in the legends. The
crosses indicates the expected position of a background object at the same
epoch, following the same colour code. The companions for HIP 28474, HIP
78549, HIP 15274, HIP 71899 and GJ 3346 (updated from the dedicated work
published in Bonavita et al. (2020), which only included GaiaDR2 epoch), are
clearly found to be co-moving with our targets.

###  4.2 Common proper motion confirmation

Multiple epochs, used to clarify the bound or background nature of our
candidates, were available for 9 of the program stars. Except for HIP 15247
and HD 60584, which were re-observed with SPHERE as part of the program, all
additional epochs were retrieved from other surveys, catalogues (including
Gaia) or papers dedicated to specific objects. The complete list of
astrometric measurements for all our systems is presented in Table 7, together
with the references used for each entry. Figure 4 shows the resulting common
proper motion analyses for both the co-moving and background interlopers. Note
that for HD 60584 we detected two sources, one at 0.5 arcsecs (CC1, discussed
in Sec. 4.7) and one at $\sim$3 arcsecs (CC2), shown in Fig. 4 and confirmed
to be background. The remaining candidates are bright companions at very small
separation and are then very likely physically related as the probability of
having such bright background stars at these separations is very low. To
confirm this, we used the code described in Section 5.2 of Chauvin et al.
(2015) and adapted it to our results to estimate the probability of finding a
background contaminant at the given separation and contrast as a function of
galactic coordinates by comparison with the prediction of the Besançon
galactic model (Robin et al., 2012). As expected all the resulting
probabilities (reported in the last column of Table 5) are below 10-4. A
further confirmation of common proper motion is also provided by the agreement
between the properties of the imaged companions with observed $\Delta\mu$, as
discussed in Sec. 4.4.

Figure 5: Comparison between the spectra of five of the companions detected at
high SNR (black bullets with error bars) with the best fit from SPLAT
(Burgasser & Splat Development Team, 2017), showing in red the best fit among
the spectral standards provided in SPLAT, and in blue the overall best fit
among all available templates.

###  4.3 Companion spectra

Spectra for the bright companions (providing relatively high SNR data) were
obtained using the IFS data. We used the SpeX Prism Library Analysis Toolkit
(SPLAT; Burgasser & Splat Development Team, 2017) to estimate the spectral
classification of each companion. We used the built-in spectral fitting
function in SPLAT to compare, by minimising the $\chi^{2}$ value, the observed
spectra to both the SPLAT near-infrared spectral standards and to the full
library of templates available in SPLAT. For bright companions, we simply used
the spectrum obtained by rotating and summing the images. For HIP 21152 B,
which was not detectable without removing the speckle pattern, we injected
negative point spread functions (derived from the flux calibration) on the
individual monochromatic images at the average companion position, and changed
its intensity minimising the root mean square of the residuals in area of
$9\times 9$ pixels centred on this mean position. Figure 5 shows the spectral
standard (red) and template (blue) providing the lowest $\chi^{2}$ values to
the observed spectrum of each detected companion. Note that the images of HIP
15247 B was saturated at most wavelengths, so it was not possible to obtain an
usable spectrum. Among the five remaining companions, four have an estimated
mid- to late-M spectral type, while HIP 21152 B is clearly a substellar object
and compatible with a late-L or early-T spectrum.
The strong absorption feature visible in the spectrum of HIP 78549 B is most
likely spurious and the result of the extremely low quality of the wavelength
calibration available for this object, particularly between 1.32 and 1.45
$\mu$m. We therefore masked this region of the spectrum while performing the
fit. The resulting mid M spectral type is in agreement with the properties
estimated from the photometry.

Figure 6: 2D maps representing the sky area compatible with the TGAS-EDR3
$\Delta\mu$ reported in Table 2. The position of the companions is marked with
a red star. Colours are according to the dynamical mass responsible for the
$\Delta\mu$ at a give distance; the same logarithmic scale was used for all
stars, according to the colour scale shown on the bottom of the figure. The
empty area at center is the area covered by the coronagraphic mask.

Figure 7: Left Panel: PA of the detected companions VS the direction of the
$\Delta\mu$. The shaded error bars show the extend of the expected change in
angle due to the orbital motion between the SPHERE observation and the Gaia
EDR3 epoch. Right Panel: Comparison between the values of the mass of the
detected companions derived using FORECAST, and those obtained from photometry
and evolutionary models (as described in Sec. 2.3). Both values of the masses
are reported in Table 8 for all companions. In both panels blue symbols are
high SNR detections; red symbols are low SNR candidates that needs further
confirmation.

###  4.4 FORECAST (Finely Optimised REtrieval of Companions of Accelerating
STars)

Since the $\Delta\mu$ can be considered as an approximation of the
instantaneous acceleration due to an unseen companion, it can be represented
as a vector in the plane of the sky directed toward the position of the
companion - at the epoch of the latest astrometry observation. The position
angle of an imaged companion compatible with the $\Delta\mu$ should then be
along the same direction of the acceleration, plus or minus the change in
angle due to the orbital motion of the companion between the latest astrometry
epoch and the imaging one. Based on these considerations, it is possible to
highlight a region on the plane of the sky where the companion compatible with
the $\Delta\mu$ should lie, based on the $\Delta\mu$ orientation, and also
associate a value of the companion mass corresponding to each point in the
resulting 2D map, based on the $\Delta\mu$ absolute value. An example of the
$\Delta\mu$ maps obtained with this method using the $\Delta\mu$ at the epoch
of $Gaia$ EDR3 (2016.0) is shown in Fig. 6, while a complete description of
the method, and of the FORECAST (Finely Optimised REtrieval of Companions of
Accelerating STars) code used to produce the maps will be the subject of a
dedicated companion publication (Bonavita et al. 2022, in preparation). In
each image, the position of the detected companion is marked as a star. As all
companions lie within the allowed region (as shown in the left panel of Fig.
7, which compares the PAs of the companions and those of the $\Delta\mu$
vectors), we could also obtain a first estimate the expected companion mass at
that position and compare it with the values of the value of the mass derived
from the photometry. The dynamical masses ($M_{\Delta\mu}$) were estimated
using the method described in Kervella et al. (2019), which allows to also
take into account the effect of the unknown orbital eccentricity and
inclination, as well as that of the observing window smearing, which are
instead not taken into account by the COPAINS tool. The comparison with the
photometric masses ($M_{Phot}$) is shown in the right panel of Fig. 7, with
the error bars on the values of $M_{\Delta\mu}$ taking into account the errors
on the $\Delta\mu$ and companion position, and those on $M_{Phot}$ mainly
arising from the uncertainties on the stellar ages. The good agreement between
the values shows the potential of our method in providing a high number of
potential new benchmark objects.

###  4.5 HIP 21152 B: a new bound substellar companion in the Hyades

The companion to HIP 21152 is clearly the most interesting of our high SNR
detections. The IRDIS photometry and the IFS spectra, shown in Fig. 5, point
towards an early T spectral type. The mass of the object, as judged from its
spectral type and age, and adopting the models from Baraffe et al.
(2015)777New atmospheric models have been recently developed by Phillips et
al. (2020). However, such models (known as ATMO2020) are mostly valid for
relatively old ultra-cool objects (late-T and Y companions). Therefore, given
the age and brightness of HIP 21152 B as well as the estimated spectral type,
we decided that the models from Baraffe et al. (2015) would be more suited for
the mass estimate in this case. The same applies to the other BD companions
described in Sec. 4.6 and 4.7, is estimated to be $0.032\pm
0.005~{}M_{\odot}$. This is also in good agreement with the mass derived from
the FORECAST analysis, which is $0.021\pm 0.007~{}M_{\odot}$.
The Lithium-depletion boundary, an observational limit that separates low-mass
stars from brown dwarfs based on their ability to burn Li in their cores, has
been estimated to occur around spectral type L3.5 - L4 in Hyades (Martín et
al., 2018). Currently, about a dozen objects with spectral type L3.5 or later
claimed as members of the cluster. Lodieu et al. (2014) published spectra of
12 L-dwarf candidates from Hogan et al. (2008), and confirmed one of them as a
potential brown dwarf member of Hyades, with spectral type L3.5. The same
objects has later been listed as a L4 member of Hyades, with Li absorption
detected in the spectra by Martín et al. (2018). Four more L-type members (two
L5 and two L6) have been confirmed in Schneider et al. (2017); Pérez-Garrido
et al. (2017, 2018). Bouvier et al. (2008) were the first to report the
existence of T-type candidate members in Hyades. The membership of one of them
(CFHT-Hy-21) has been confirmed by Lodieu et al. (2014), whereas the other one
(CFHT-Hy-20) is still considered a candidate (Lodieu et al., 2014; Zhang et
al., 2021), given the lack of radial velocity measurement. Four T-type
probable members have been reported in Zhang et al. (2021), spanning the
spectral type range T2 to T6.5. The multiplicity of Hyades stars has been
assessed through imaging (Reid & Gizis, 1997; Patience et al., 1998; Siegler
et al., 2003; Duchêne et al., 2013), high-resolution spectroscopy (Reid &
Mahoney, 2000), a combination of the two (Guenther et al., 2005), and $Gaia$
astrometry (Deacon & Kraus, 2020). While several binary systems consisting of
two substellar objects, or objects close to the (sub)stellar border, were
reported in Siegler et al. (2003); Reid & Mahoney (2000); Duchêne et al.
(2013), no substellar companions to FGK stars have so far been reported in
Hyades, making HIP 21152 B the first of its kind. HIP 22152 B thus occupies a
unique place in the luminosity-age parameter space compared to the known
population of directly-imaged systems, making it a highly valuable benchmark
for empirical constraints to theoretical models.
BD companions such HIP 22152 B have been shown in the past to be themselves
close pairs of substellar objects (see e.g. Martín et al., 2000; Potter et
al., 2002) and optimised PSF subtraction methods have been recently developed
to highlight the presence of close companions to BDs detected with SPHERE (see
e.g. Lazzoni et al., 2020). Such methods rely on the detection and analysis of
features such as elongation in the companion’s PSF incompatible with the
expected effects of ADI. Although a detailed analysis would benefit from a new
set of higher quality data, we can say that no such features were detected in
our images for HIP 21152 B. Moreover, to be on stable orbits, possible
additional companions would need to have separations within HIP 21152 B’s Hill
Radius, which we estimated to be roughly at 3.57 au, for the optimistic case
of a circular orbit. At the distance of HIP 21152 B ($\sim$43 pc), this
corresponds to a projected separation of roughly 82 mas. While this target has
good potential for the detection of additional (possibly less massive)
companions, an analysis like the one described by Lazzoni et al. (2020) will
require higher quality data than those presented in this work.

###  4.6 HIP 29724 B: a new high mass brown dwarf

We also detected a very close (99.9$\pm$1.5 mas) companion to HIP 29724. The
photometry suggests a mass of 0.063$\pm$0.008 M⊙, thus placing HIP 29724 B
also in the sub-stellar regime. The FORECAST analysis confirms that the
companion is compatible with the observed TGAS-EDR3 $\Delta\mu$, both in terms
of position and corresponding mass ($0.067\pm 0.021~{}M_{\odot}$). With a
projected separation of just 6.3 au, RV monitoring could significantly
contribute to the refinement of the BD orbit and dynamical mass. However,
there are no high-precision RV measurements available up to now. Sparse RV
data over several decades (Nordström et al., 2004; Torres et al., 2006; Gaia
Collaboration et al., 2018) are constant within 1.2 km/s. The spectrum of the
companion, shown in Fig. 5, is compatible with a late M spectral type,
although a later spectral type is not completely excluded, given the
uncertainties caused by the companion’s proximity to the edge of the
coronagraph.
As it was the case for HIP 21152 B, the PSF of HIP 29724 B does not show any
elongation beyond what expected as result of the ADI. We estimated for this
companion an Hill Radius of 1.71 au (27.2 mas, assuming a circular orbit) thus
limiting the detectability of possible additional companions to roughly equal-
mass ones, considering the spatial resolution of our images.

###  4.7 HD 60584 B and HIP 63734 B: two more potential low mass brown dwarf
candidate companions

The $\Delta\mu$ maps obtained with FORECAST are not only useful to confirm the
nature of the candidates found in objects with highly significant $\Delta\mu$,
but could in principle also be used as _finding charts_ to highlight and
retrieve possible additional companions appearing in the imaging data at a SNR
lower than the threshold required for a confirmed detection, which would
otherwise be overlooked. We had in fact noticed that all our high SNR
detections were around stars for which the ratio between the $\Delta\mu$
absolute value and its error (hereafter $SNR_{\Delta\mu}$) is higher than 10.
So we decided to produce the FORECAST maps also for the targets with low or
intermediate $SNR_{\mathrm{Max}}$ (HD 60584, HIP 63734, and HIP 22506) as a
test for their possible use as _finding charts_.
While the data for HIP 63734 were taken in fairly good atmospheric conditions,
the target was observed quite far from meridian passage so that field rotation
is limited (only 7.13 degrees). The analysis of the IFS data with ASDI-PCA
revealed a candidate companion with $SNR\sim 8.5$, at separation $555\pm 2$
mas and PA=$329.6\pm 0.2$ degree, with a contrast of dJ=12.08 and dH=11.26.
The comparison with Baraffe et al. (2003) models yields an evolutionary mass
of $0.011\pm 0.005$M⊙. While the PA of the object is fully compatible with
that of the $\Delta\mu$, the corresponding companion mass is a bit higher
($0.032\pm 0.020$M⊙) is a bit higher than the evolutionary one. However, this
detection is uncertain because the small rotation angle makes the noise
distribution quite different from a Gaussian.
The case of HD 60584 is slightly more complicated. Although there were four
available epochs, the resulting IFS data were all of relatively poor quality.
The second and third epochs were taken at about one month interval; since we
did not expect a large orbital motion between them, we combined them as a
single observation. This allowed us to identify a point source compatible with
the FORECAST predictions at a separation 543$\pm$5 mas and PA=52.5$\pm 0.5$
degrees, with a SNR of 4.9. At that position, the mass of a companion
compatible with the $\Delta\mu$ would have to be below 0.01 M⊙ which, at the
relatively high age of the targets would mean that the companion would have to
be fairly faint. While the IFS photometry points towards a higher mass
($0.028\pm 0.009$M⊙), given the high uncertainties due to the image and
calibration quality and the very field small rotation angle we still deemed it
acceptable. As for the other BDs, no evident elongation pointing towards
possible additional companions was observed for the PSF of HIP 63734 B and HD
60584 B. However, given the low SNR of the detections, we estimate that the
only potentially detectable companions within the Hill Radius of these BDs
(103 and 80 mas, respectively) would have been equal-mass ones.
Although further investigation is required to confirm the nature of both HD
60584 B and HIP 63734 B, mostly due to the poor quality of the imaging data,
these additional detections clearly show the power of the approach, which
pushes the $\Delta\mu$ method towards companions with smaller masses, whose
detection is more uncertain and likely to be below the usual 10 $\sigma$
threshold used for automatic retrieval of point sources in imaging data.
Although repeated observations will be needed to confirm low SNR imaging
detections, with the use of FORECAST a single observation is potentially
enough to confirm that a companion observed in high contrast imaging is the
one responsible for the $\Delta\mu$, and therefore co-moving. Other low SNR
point sources were retrieved around HIP 22506, but were discarded mostly based
on the strong disagreement between their brightness and the value of the mass
compatible with the position within the FORECAST map. This also shows the
power of FORECAST in terms of vetting of possible background or spurious
sources.

##  5 Discussion

The COPAINS selection method has proven very successful in ensuring a high
detection rate in both the stellar and sub-stellar regime. We detected a total
of 14 candidate companions. Two were known binaries (HIP 15247 B and HIP 78549
B) and four were identified as background sources thanks to additional
available epochs found in the literature, which also allowed us to confirm the
common proper motion nature of four additional new stellar companions,
including the white dwarf companion to GJ 3346, described in Bonavita et al.
(2020). The masses of the remaining four candidates, derived using the
available photometry and the evolutionary models from Baraffe et al. (2015),
place them in the sub-stellar regime. Such high sub-stellar companion
detection rate confirms the efficiency of the COPAINS selection method, as
well as the new FORECAST code used to confirm their nature, based on the
agreement between their properties with the predictions based on the measured
$\Delta\mu$.

###  5.1 Comparison with blind surveys

To quantify the improvement in terms of detection rate compared to blind
surveys, we compared our results with those from the first 150 targets from
the SHINE survey (Vigan et al., 2021). Only 93 of the SHINE-150 targets are
included in TGAS and DR2, and only 13 have $\Delta\mu$ more significant than 3
$\sigma$, and would have therefore been selected for COPAINS. Three of these
SHINE $\Delta\mu$ stars have sub-stellar companions, including HIP 65426, one
of the two new SHINE detections. The resulting sub-stellar companions
frequency is then $\sim 25\%$ which is significantly higher than what obtained
with the blind approach ($\sim 9\%$ without any correction due to prior
knowledge about the companions, see Vigan et al. (2021) for details), once
again showing the efficiency of the COPAINS selection method, especially when
combined with the FORECAST maps.

###  5.2 Limitations

We have demonstrated with our campaign the power of using informed target
selection processes such as the COPAINS tool (Fontanive et al., 2019) to
identify new directly-imaged companions. The high detection rate obtained here
strongly validates the use of such approaches in survey designs, despite the
numerous assumptions and limitations of the work conducted in this pilot
survey. Indeed, our original sample selection considered catalogue proper
motions taken at face value. Instead, a more accurate approach would require
placing all measurements in the same reference frame and at the same epoch,
such as the Hipparcos-$Gaia$ Catalog of Accelerations (HGCA) defined by Brandt
(2018, 2021). These catalogues provides Hipparcos and $Gaia$ DR2/EDR3 proper
motions, as well as a $Gaia$-Hipparcos scaled positional differences (close to
the TGAS proper motions), placing all proper motions at the epochs of GaiaDR2
and EDR3, respectively, with recalibrated uncertainties. Nonetheless, given
the number of approximations made in COPAINS, these differences were found to
be negligible, especially given the use made of the resulting computed trends
(i.e., visual selection based on comparisons to expected detection limits). As
COPAINS considers long-term proper motions as representative of the system’s
center-of-mass motion, and short-term measurements as the instantaneous reflex
motion of the host, the considered $\Delta\mu$ are only good approximations
for systems with orbital periods that roughly match the long- and short-term
timescales of the considered astrometric catalogues (see Fontanive et al.,
2019). These limitations are further added to the adopted eccentricity
distribution, primarily impacting the width of the computed solutions, and the
fact that the approach assumes face-on orbits, which implies that estimated
trends actually provide lower mass limits for a given separation. While
information from the now available HGCA catalogues (Brandt, 2018, 2021) or
proper motion anomalies measured by Kervella et al. (2019, 2022) would
therefore provide more robust and reliable astrometric trends to use for
selection purposes (and should consistently be used for orbital and dynamical
mass constraints), our results were not impacted by the use of un-corrected
catalogue values, and we have nonetheless shown that the idea behind our
method offers a highly promising pathway for future observing programs.

Figure 8: Mass ratio (Mcmp/Mstar, left panel) and companion mass (MJup, right
panel) vs separation (in au) of the four COPAINS sub-stellar candidates (star
symbols) compared to those of previously known DI companions (filled circles).
The colour bar shows the significativity of the TGAS-DR2 $\Delta\mu$ (SNRΔμ)
used for the COPAINS selection. Objects with SNR${}_{\Delta\mu}<3$ (or not in
TGAS, and therefore without a measurement of the $\Delta\mu$) are shown in
gray.

##  6 Conclusions

We presented the results of the COPAINS survey, a search for companions to 25
stars selected using the COPAINS tool by Fontanive et al. (2019), and the
discovery of four new brown dwarf companions: HIP 21152 B, HIP 29724 B, HD
60584 B and HIP 63734 B.
The value of blind surveys of course lies in their ability to constrain the
underlying planet and sub-stellar companion population, but comes with a high
cost in terms of telescope time. On the other hand, surveys like COPAINS offer
an undeniably efficient selection method, providing a much higher success rate
with a considerably smaller time commitment. Moreover, the possibility to
derive model independent mass estimates for the companions to accelerating
stars also means that each new detection arising from surveys like COPAINS can
be added to the currently scarce number of much needed benchmark objects,
providing new crucial constraints the evolutionary models. Given the good
agreement between the values of the masses of these companions obtained from
the photometry with the model-independent ones based on the $\Delta\mu$, this
work represents a considerable addition to the current benchmarks sample.
The combination with the FORECAST maps ensures a high detection rate even when
the quality of the imaging data is not ideal, while at the same time further
enhancing the sensitivity to lower mass companions. Fig. 8 shows the mass
ratio (left panel) and companion mass (right panel) vs separation of the
COPAINS sub-stellar candidates compared to those of the known DI companions
(data from exoplanet.eu updated on April 4th, 2022). An estimate of the
$\Delta\mu$ was possible for about 40% of the known companions and about half
of these (shown as coloured dots in Fig. 8) would have been selected using
COPAINS. This plot once again shows how a selection like the one provided by
COPAINS can already lead to the detection of companions well in the planetary
mass regime.
Catalogues like those by Brandt et al. (2019) and Kervella et al. (2022)
provide a more robust estimate of the accelerations, and therefore their use
with COPAINS is likely to lead to an even more effective selection. Moreover,
these acceleration catalogues can also be used to retrieve a time series of
absolute astrometry which, combined with the imaging data, allows for a more
detailed characterisation of the orbit, and thus of the dynamical mass (see
e.g. Drimmel et al., 2021). The availability of Gaia-only accelerations in the
upcoming full third GaiaRelease (DR3) will allow for another great step
further. It will in fact not only free the method from the boundaries so far
imposed by the use of external catalogue as source of long term proper motion,
but more importantly will allow for a significant improvement in terms of
uncertainties, thus allowing future survey to truly focus on targets with
accelerations caused by planetary mass companion.

Table 1: Sample characteristics. All the values of the parallax are from
GaiaEDR3. The values of the age (Age${}^{max}_{min}$) and stellar mass
(Mass${}^{max}_{min}$) are derived as described in Sec. 2.2 and 2.3 (see also
Appendix A for details on the age derivation for the single objects). The last
column includes the observing period for which the target was originally
proposed for and therefore the selection method applied, as detailed in
Section 2.1

ID | RA | Dec | Parallax | SpType | $J$ | $H$ | $K$ | Age${}^{max}_{min}$ | Mass${}^{max}_{min}$ | Sel
---|---|---|---|---|---|---|---|---|---|---
| (hh:mm:ss) | ($\degr$:$\arcmin$:$\arcsec$) | (mas) |  | mag | mag | mag | Myr | M⊙ |
HIP 15247 | 1:10:09.411 | -3:31:48.575 | 20.37 $\pm$ 0.03 | F6V | 6.457 | 6.209 | 6.099 | 45${}^{150}_{30}$ | 1.23${}^{+0.006}_{-0.003}$ | P104
HIP 17439 | 3:44:09.0243 | -38:16:56.771 | 61.84 $\pm$ 0.02 | K2V | 5.462 | 5.088 | 4.934 | 700${}^{900}_{500}$ | 0.87${}^{+0.001}_{-0.001}$ | P104
HIP 21152 | 4:32:04.7457 | 5:24:36.069 | 23.11 $\pm$ 0.03 | F5V | 5.593 | 5.385 | 5.333 | 625${}^{700}_{600}$ | 1.44${}^{+0.002}_{-0.002}$ | P104
HIP 21317 | 4:34:35.2511 | 15:30:16.873 | 21.67 $\pm$ 0.02 | F8 | 6.745 | 6.552 | 6.445 | 625${}^{700}_{600}$ | 1.12${}^{+0.001}_{-0.001}$ | P100
HIP 22506 | 4:50:35.4147 | -41:02:51.426 | 19.83 $\pm$ 0.05 | G9V | 7.438 | 7.099 | 6.876 | 50${}^{125}_{40}$ | 0.96${}^{+0.002}_{-0.009}$ | P104
GJ 3346 | 5:19:59.4774 | -15:50:24.411 | 42.09 $\pm$ 0.02 | K3.5Vk: | 6.856 | 6.284 | 6.205 | 5400${}^{6500}_{4300}$ | 0.74${}^{+0.003}_{-0.003}$ | P100
HIP 27441 | 5:48:36.7913 | -39:55:55.814 | 23.59 $\pm$ 0.01 | K0V | 7.407 | 7.061 | 6.912 | 250${}^{350}_{150}$ | 0.90${}^{+0.001}_{-0.001}$ | P100
HIP 28474 | 6:00:41.2853 | -44:53:50.304 | 18.48 $\pm$ 0.01 | G8V | 7.73 | 7.433 | 7.321 | 42${}^{125}_{35}$ | 0.96${}^{+0.001}_{-0.020}$ | P104
HIP 29724 | 6:15:38.8408 | -57:42:05.96 | 15.86 $\pm$ 0.01 | G2V | 7.715 | 7.447 | 7.346 | 150${}^{250}_{100}$ | 1.04${}^{+0.001}_{-0.001}$ | P104
HIP 33690 | 6:59:59.8409 | -61:20:12.444 | 54.53 $\pm$ 0.01 | G9V | 5.459 | 5.097 | 4.987 | 650${}^{800}_{500}$ | 0.94${}^{+0.001}_{-0.002}$ | P104
HD 57852 | 7:20:21.4547 | -52:18:42.709 | 28.63 $\pm$ 0.23 | F5V | 5.28 | 5.13 | 4.946 | 200${}^{300}_{150}$ | 1.41${}^{+0.006}_{-0.006}$ | P104
HD 60584 | 7:34:18.6723 | -23:28:25.17 | 32.75 $\pm$ 0.04 | F5V+F6V | 5.03 | 4.9 | 4.773 | 1000${}^{1700}_{300}$ | 1.35${}^{+0.012}_{-0.016}$ | P100
HIP 52462 | 10:43:28.4085 | -29:03:51.014 | 46.49 $\pm$ 0.02 | K1V | 6.176 | 5.77 | 5.66 | 170${}^{250}_{120}$ | 0.86${}^{+0.001}_{-0.001}$ | P104
HIP 56153 | 11:30:35.5865 | -57:08:02.252 | 44.53 $\pm$ 0.02 | K3.5V(k) | 6.495 | 6.019 | 5.868 | 700${}^{1000}_{500}$ | 0.79${}^{+0.001}_{-0.001}$ | P102
HIP 59726 | 12:14:57.6323 | -41:08:21.243 | 31.14 $\pm$ 0.02 | G5V | 6.31 | 6.008 | 5.925 | 700${}^{1000}_{500}$ | 1.02${}^{+0.002}_{-0.003}$ | P104
HIP 61804 | 12:40:00.1103 | -17:41:03.596 | 16.20 $\pm$ 0.31 | G3V | 7.295 | 7.043 | 6.869 | 120${}^{200}_{80}$ | 1.12${}^{+0.009}_{-0.010}$ | P104
HIP 63734 | 13:03:39.0733 | -16:20:11.414 | 18.49 $\pm$ 0.03 | F7/8V | 6.752 | 6.522 | 6.436 | 150${}^{300}_{100}$ | 1.21${}^{+0.006}_{-0.006}$ | P104
HIP 63862 | 13:05:16.9255 | -50:51:23.776 | 21.06 $\pm$ 0.02 | G6V | 7.158 | 6.834 | 6.744 | 200${}^{300}_{120}$ | 1.03${}^{+0.001}_{-0.002}$ | P100
HIP 71899 | 14:42:23.1023 | 21:17:35.386 | 21.94 $\pm$ 0.02 | F8 | 6.447 | 6.223 | 6.172 | 300${}^{3000}_{100}$ | 1.18${}^{+0.011}_{-0.012}$ | P102
HIP 78549 | 16:02:13.5632 | -22:41:15.023 | 7.01 $\pm$ 0.03 | B9.5V | 7.037 | 7.038 | 6.97 | 11${}^{12}_{4}$ | 2.61${}^{+0.010}_{-0.014}$ | P104
HIP 108912 | 22:03:42.303 | -60:26:14.87 | 23.38 $\pm$ 0.02 | G2V | 6.773 | 6.529 | 6.444 | 300${}^{400}_{200}$ | 1.07${}^{+0.002}_{-0.002}$ | P104
HIP 112491 | 22:47:09.1673 | -32:40:30.874 | 36.43 $\pm$ 0.02 | G8V | 6.295 | 5.958 | 5.852 | 700${}^{900}_{500}$ | 0.95${}^{+0.001}_{-0.002}$ | P104
HIP 112581 | 22:48:06.8092 | -37:45:23.989 | 26.14 $\pm$ 0.02 | G0VCH-0.3 | 6.415 | 6.172 | 6.1 | 600${}^{800}_{450}$ | 1.09${}^{+0.002}_{-0.003}$ | P104
CD-69 2101 | 23:31:00.5329 | -69:05:09.756 | 33.03 $\pm$ 0.01 | K3V | 7.345 | 6.824 | 6.712 | 350${}^{500}_{200}$ | 0.77${}^{+0.001}_{-0.001}$ | P100
HIP 116768 | 23:39:54.9912 | 9:40:38.345 | 14.05 $\pm$ 0.29 | A2m | 5.563 | 5.488 | 5.471 | 780${}^{1040}_{520}$ | 1.88${}^{+0.045}_{-0.062}$ | P104

Table 2: Proper motion values from TGAS, DR2 and EDR3 and the resulting
$\Delta\mu$ values obtained considering TGAS or Tycho-II as source for long
term proper motions and DR2 or EDR3 as sources short-term proper motions.

ID | pmRA | pmDE | $\Delta\mu$
---|---|---|---
| TYCHO-2 | TGAS | DR2 | EDR3 | TYCHO-2 | TGAS | DR2 | EDR3 | TYC-TGAS | TGAS-DR2 | TGAS-DR3
HIP 15247 | 77.70 $\pm$ 1.40 | 79.25 $\pm$ 0.04 | 82.10 $\pm$ 0.09 | 82.10 $\pm$ 0.03 | -45.80 $\pm$ 1.30 | -47.25 $\pm$ 0.03 | -49.08 $\pm$ 0.08 | -49.05 $\pm$ 0.03 | 2.13 $\pm$ 0.05 | 3.39 $\pm$ 0.09 | 3.36 $\pm$ 0.05
HIP 17439 | 209.90 $\pm$ 1.20 | 209.07 $\pm$ 0.04 | 208.91 $\pm$ 0.03 | 209.06 $\pm$ 0.02 | 291.00 $\pm$ 1.20 | 289.26 $\pm$ 0.05 | 289.30 $\pm$ 0.05 | 289.32 $\pm$ 0.02 | 1.93 $\pm$ 0.05 | 0.16 $\pm$ 0.05 | 0.06 $\pm$ 0.05
HIP 21152 | 113.20 $\pm$ 1.30 | 112.59 $\pm$ 0.04 | 112.50 $\pm$ 0.13 | 112.17 $\pm$ 0.03 | 5.40 $\pm$ 1.30 | 8.06 $\pm$ 0.02 | 7.58 $\pm$ 0.06 | 7.76 $\pm$ 0.02 | 2.73 $\pm$ 0.04 | 0.49 $\pm$ 0.06 | 0.51 $\pm$ 0.04
HIP 21317 | 98.10 $\pm$ 1.00 | 101.12 $\pm$ 0.10 | 100.87 $\pm$ 0.11 | 100.96 $\pm$ 0.03 | -26.70 $\pm$ 1.10 | -26.74 $\pm$ 0.06 | -26.86 $\pm$ 0.07 | -26.81 $\pm$ 0.02 | 3.02 $\pm$ 0.10 | 0.28 $\pm$ 0.14 | 0.18 $\pm$ 0.10
HIP 22506 | 37.10 $\pm$ 1.10 | 36.77 $\pm$ 0.04 | 36.45 $\pm$ 0.13 | 36.46 $\pm$ 0.06 | 69.90 $\pm$ 1.10 | 69.08 $\pm$ 0.05 | 68.07 $\pm$ 0.14 | 68.59 $\pm$ 0.07 | 0.88 $\pm$ 0.08 | 1.06 $\pm$ 0.15 | 0.58 $\pm$ 0.08
GJ 3346 | 174.30 $\pm$ 1.30 | 174.02 $\pm$ 0.06 | 173.57 $\pm$ 0.05 | 173.70 $\pm$ 0.01 | 201.20 $\pm$ 1.40 | 206.39 $\pm$ 0.06 | 207.56 $\pm$ 0.06 | 207.71 $\pm$ 0.01 | 5.20 $\pm$ 0.07 | 1.25 $\pm$ 0.08 | 1.35 $\pm$ 0.07
HIP 27441 | 26.50 $\pm$ 1.10 | 28.43 $\pm$ 0.05 | 28.46 $\pm$ 0.05 | 28.43 $\pm$ 0.01 | 71.10 $\pm$ 1.30 | 66.48 $\pm$ 0.05 | 66.21 $\pm$ 0.05 | 66.38 $\pm$ 0.01 | 5.01 $\pm$ 0.06 | 0.27 $\pm$ 0.07 | 0.11 $\pm$ 0.06
HIP 28474 | 16.80 $\pm$ 1.00 | 17.52 $\pm$ 0.07 | 18.15 $\pm$ 0.05 | 18.22 $\pm$ 0.01 | 21.10 $\pm$ 1.10 | 23.09 $\pm$ 0.08 | 23.26 $\pm$ 0.05 | 23.47 $\pm$ 0.01 | 2.12 $\pm$ 0.07 | 0.65 $\pm$ 0.08 | 0.79 $\pm$ 0.07
HIP 29724 | 30.20 $\pm$ 1.30 | 29.41 $\pm$ 0.07 | 27.67 $\pm$ 0.04 | 27.51 $\pm$ 0.02 | 48.30 $\pm$ 1.30 | 47.79 $\pm$ 0.07 | 48.46 $\pm$ 0.04 | 48.50 $\pm$ 0.02 | 0.94 $\pm$ 0.08 | 1.86 $\pm$ 0.08 | 2.02 $\pm$ 0.08
HIP 33690 | -160.80 $\pm$ 1.30 | -161.89 $\pm$ 0.04 | -162.07 $\pm$ 0.05 | -161.87 $\pm$ 0.02 | 266.30 $\pm$ 1.60 | 264.87 $\pm$ 0.04 | 264.64 $\pm$ 0.04 | 264.84 $\pm$ 0.02 | 1.80 $\pm$ 0.04 | 0.29 $\pm$ 0.06 | 0.04 $\pm$ 0.04
HD 57852 | -62.50 $\pm$ 1.20 | -36.88 $\pm$ 0.05 | -37.71 $\pm$ 0.59 | -37.05 $\pm$ 0.32 | 107.00 $\pm$ 1.50 | 146.69 $\pm$ 0.05 | 148.39 $\pm$ 0.56 | 146.29 $\pm$ 0.29 | 47.24 $\pm$ 0.30 | 1.89 $\pm$ 0.56 | 0.43 $\pm$ 0.30
HD 60584 | -83.50 $\pm$ 1.10 | -88.05 $\pm$ 0.04 | -88.13 $\pm$ 0.07 | -88.13 $\pm$ 0.02 | -0.80 $\pm$ 1.00 | -0.59 $\pm$ 0.04 | -0.74 $\pm$ 0.09 | -0.86 $\pm$ 0.04 | 4.55 $\pm$ 0.05 | 0.17 $\pm$ 0.09 | 0.28 $\pm$ 0.05
HIP 52462 | -212.50 $\pm$ 1.50 | -215.57 $\pm$ 0.03 | -215.54 $\pm$ 0.06 | -215.48 $\pm$ 0.01 | -50.00 $\pm$ 1.20 | -49.88 $\pm$ 0.04 | -50.12 $\pm$ 0.06 | -49.89 $\pm$ 0.02 | 3.08 $\pm$ 0.04 | 0.24 $\pm$ 0.07 | 0.09 $\pm$ 0.04
HIP 56153 | -553.30 $\pm$ 2.00 | -555.35 $\pm$ 0.07 | -555.29 $\pm$ 0.17 | -555.33 $\pm$ 0.02 | 36.40 $\pm$ 1.50 | 36.13 $\pm$ 0.06 | 35.91 $\pm$ 0.22 | 36.13 $\pm$ 0.02 | 2.07 $\pm$ 0.07 | 0.23 $\pm$ 0.22 | 0.02 $\pm$ 0.07
HIP 59726 | -312.80 $\pm$ 0.90 | -313.95 $\pm$ 0.04 | -313.90 $\pm$ 0.05 | -313.97 $\pm$ 0.02 | -78.50 $\pm$ 0.90 | -77.04 $\pm$ 0.03 | -77.17 $\pm$ 0.03 | -77.00 $\pm$ 0.01 | 1.86 $\pm$ 0.03 | 0.14 $\pm$ 0.05 | 0.04 $\pm$ 0.03
HIP 61804 | -48.00 $\pm$ 1.30 | -45.70 $\pm$ 0.07 | -47.83 $\pm$ 0.38 | -46.64 $\pm$ 0.34 | -10.40 $\pm$ 1.40 | -11.60 $\pm$ 0.05 | -12.23 $\pm$ 0.32 | -11.15 $\pm$ 0.22 | 2.59 $\pm$ 0.33 | 2.22 $\pm$ 0.38 | 1.04 $\pm$ 0.33
HIP 63734 | -108.70 $\pm$ 1.20 | -108.30 $\pm$ 0.05 | -108.48 $\pm$ 0.10 | -108.37 $\pm$ 0.03 | -28.90 $\pm$ 1.10 | -29.55 $\pm$ 0.03 | -29.31 $\pm$ 0.07 | -29.30 $\pm$ 0.02 | 0.76 $\pm$ 0.04 | 0.30 $\pm$ 0.09 | 0.26 $\pm$ 0.04
HIP 63862 | -135.50 $\pm$ 1.10 | -134.34 $\pm$ 0.04 | -134.15 $\pm$ 0.11 | -134.34 $\pm$ 0.02 | -1.10 $\pm$ 1.10 | -4.45 $\pm$ 0.05 | -4.65 $\pm$ 0.08 | -4.45 $\pm$ 0.02 | 3.54 $\pm$ 0.05 | 0.28 $\pm$ 0.11 | 0.00 $\pm$ 0.05
HIP 71899 | -108.00 $\pm$ 1.00 | -107.27 $\pm$ 0.03 | -108.39 $\pm$ 0.06 | -108.42 $\pm$ 0.01 | -31.50 $\pm$ 1.00 | -34.51 $\pm$ 0.04 | -35.21 $\pm$ 0.07 | -35.14 $\pm$ 0.02 | 3.10 $\pm$ 0.03 | 1.32 $\pm$ 0.07 | 1.31 $\pm$ 0.03
HIP 78549 | -12.00 $\pm$ 1.40 | -12.54 $\pm$ 0.04 | -12.51 $\pm$ 0.11 | -12.53 $\pm$ 0.03 | -24.70 $\pm$ 1.40 | -23.13 $\pm$ 0.03 | -23.53 $\pm$ 0.06 | -23.65 $\pm$ 0.02 | 1.66 $\pm$ 0.03 | 0.40 $\pm$ 0.06 | 0.52 $\pm$ 0.03
HIP 108912 | 105.30 $\pm$ 1.40 | 106.47 $\pm$ 0.05 | 106.27 $\pm$ 0.04 | 106.40 $\pm$ 0.01 | 2.10 $\pm$ 1.40 | 2.08 $\pm$ 0.05 | 2.20 $\pm$ 0.05 | 2.00 $\pm$ 0.02 | 1.17 $\pm$ 0.05 | 0.23 $\pm$ 0.07 | 0.11 $\pm$ 0.05
HIP 112491 | 248.00 $\pm$ 1.30 | 247.31 $\pm$ 0.07 | 247.14 $\pm$ 0.08 | 247.28 $\pm$ 0.02 | -90.60 $\pm$ 1.20 | -91.24 $\pm$ 0.05 | -90.86 $\pm$ 0.06 | -91.25 $\pm$ 0.02 | 0.94 $\pm$ 0.07 | 0.42 $\pm$ 0.09 | 0.02 $\pm$ 0.07
HIP 112581 | 158.30 $\pm$ 1.60 | 156.54 $\pm$ 0.05 | 155.64 $\pm$ 0.07 | 155.72 $\pm$ 0.02 | 1.90 $\pm$ 1.20 | 1.49 $\pm$ 0.04 | 1.71 $\pm$ 0.08 | 1.57 $\pm$ 0.02 | 1.81 $\pm$ 0.05 | 0.93 $\pm$ 0.08 | 0.82 $\pm$ 0.05
CD-69 2101 | 186.90 $\pm$ 1.50 | 181.14 $\pm$ 0.63 | 185.55 $\pm$ 0.04 | 185.66 $\pm$ 0.01 | -124.50 $\pm$ 1.40 | -125.88 $\pm$ 0.75 | -126.36 $\pm$ 0.05 | -126.53 $\pm$ 0.02 | 5.92 $\pm$ 0.64 | 4.43 $\pm$ 0.64 | 4.56 $\pm$ 0.64
HIP 116768 | 88.60 $\pm$ 1.50 | 88.17 $\pm$ 0.05 | 86.91 $\pm$ 0.36 | 87.50 $\pm$ 0.28 | -11.30 $\pm$ 1.50 | -10.20 $\pm$ 0.04 | -10.18 $\pm$ 0.28 | -10.50 $\pm$ 0.19 | 1.18 $\pm$ 0.28 | 1.26 $\pm$ 0.36 | 0.74 $\pm$ 0.28

Table 3: Summary of VLT/SPHERE observations.

ID | OBS DATE | MJD | MODE | DITxNDIT | ND Filt | FoV rot | seeing | $\tau_{0}$
---|---|---|---|---|---|---|---|---
HIP 15247 | 2019-10-03 | 58759.27718 | IRDIFS-EXT | 64x2 | ND 3.5 | 19.54 | 0.89 | 0.0021
| 2019-10-18 | 58774.26027 | IRDIFS-EXT | 64x2 | ND 3.5 | 2.13 | 1.03 | 0.0024
| 2019-10-26 | 58782.22189 | IRDIFS-EXT | 64x2 | ND 3.5 | 25.60 | 1.0 | 0.0026
HIP 17439 | 2019-10-02 | 58758.30404 | IRDIFS-EXT | 32x6 | ND 3.5 | 49.90 | 1.06 | 0.0022
HIP 21152 | 2019-10-26 | 58782.29206 | IRDIFS-EXT | 64x3 | ND 3.5 | 36.63 | 1.19 | 0.0032
| 2019-10-26 | 58782.29206 | IRDIFS-EXT | 64x3 | ND 3.5 | 36.63 | 1.19 | 0.0032
HIP 21317 | 2019-03-03 | 58545.34589 | IRDIFS-EXT | 64x1 | ND 2.0 | 5.93 | 0.93 | 0.0043
HIP 22506 | 2019-10-03 | 58759.31361 | IRDIFS-EXT | 64x3 | ND 3.5 | 31.72 | 0.98 | 0.0018
GJ 3346 | 2018-01-29 | 58147.10689 | IRDIFS-EXT | 64x1 | ND 2.0 | 5.16 | 1.18 | 0.0039
HIP 27441 | 2018-10-03 | 58394.32920 | IRDIFS-EXT | 64x1 | ND 2.0 | 6.63 | 1.22 | 0.003
HIP 28474 | 2019-10-16 | 58772.26844 | IRDIFS-EXT | 64x3 | ND 3.5 | 31.85 | 1.2 | 0.002
| 2019-10-28 | 58784.31147 | IRDIFS-EXT | 64x3 | ND 3.5 | 37.70 | 1.01 | 0.0038
HIP 29724 | 2019-10-12 | 58768.32106 | IRDIFS-EXT | 64x2 | ND 3.5 | 12.38 | 1.04 | 0.0028
HIP 33690 | 2019-12-05 | 58822.24603 | IRDIFS-EXT | 64x3 | ND 3.5 | 19.75 | 0.93 | 0.0033
HD 57852 | 2019-12-14 | 58831.24541 | IRDIFS-EXT | 64x3 | ND 3.5 | 27.11 | 0.93 | 0.0089
HD 60584 | 2018-02-03 | 58152.24399 | IRDIFS-EXT | 64x1 | ND 3.5 | 0.84 | 1.01 | 0.0064
| 2018-10-08 | 58399.33920 | IRDIFS-EXT | 64x1 | ND 3.5 | 1.82 | 1.05 | 0.0024
| 2018-11-25 | 58447.22078 | IRDIFS-EXT | 64x1 | ND 3.5 | 0.82 | 0.91 | 0.0084
| 2019-12-16 | 58833.30235 | IRDIFS-EXT | 32x5 | ND 3.5 | 1.62 | 1.68 | 0.0027
HIP 52462 | 2020-01-04 | 58852.23233 | IRDIFS-EXT | 32x6 | ND 3.5 | 6.28 | 1.22 | 0.0097
HIP 56153 | 2019-02-03 | 58545.27470 | IRDIFS-EXT | 16x4 | ND 2.0 | 0.41 | 1.05 | 0.005
HIP 59726 | 2020-01-08 | 58856.26851 | IRDIFS-EXT | 64x3 | ND 3.5 | 2.98 | 1.29 | 0.0015
| 2020-01-19 | 58867.24264 | IRDIFS-EXT | 64x3 | ND 3.5 | 11.37 | 1.02 | 0.0124
HIP 61804 | 2020-02-22 | 58901.28462 | IRDIFS-EXT | 64x2 | ND 3.5 | 57.53 | 1.13 | 0.0051
HIP 63734 | 2020-02-07 | 58886.27393 | IRDIFS-EXT | 64x3 | ND 3.5 | 6.36 | 1.15 | 0.0041
HIP 63862 | 2018-02-04 | 58153.34083 | IRDIFS-EXT | 64x1 | ND 2.0 | 9.25 | 1.0 | 0.0079
HIP 71899 | 2019-03-03 | 58545.34590 | IRDIFS-EXT | 64x1 | ND 2.0 | 5.93 | 0.93 | 0.0043
HIP 78549 | 2020-03-24 | 58932.30214 | IRDIFS-EXT | 32x6 | ND 3.5 | 8.62 | 1.24 | 0.0042
HIP 108912 | 2019-10-04 | 58760.06723 | IRDIFS-EXT | 64x3 | ND 3.5 | 20.45 | 1.25 | 0.0021
HIP 112491 | 2019-10-02 | 58758.18845 | IRDIFS-EXT | 64x2 | ND 3.5 | 6.99 | 1.28 | 0.0009
HIP 112581 | 2019-10-04 | 58760.13838 | IRDIFS-EXT | 64x3 | ND 1.0 | 27.74 | 0.81 | 0.003
CD-69 2101 | 2017-10-01 | 58027.12834 | IRDIFS-EXT | 64x1 | ND 2.0 | 6.12 | 0.99 | 0.0034
HIP 116768 | 2019-10-05 | 58761.11277 | IRDIFS-EXT | 64x2 | ND 3.5 | 16.74 | 0.8 | 0.0023

Table 4: IFS contrast limits (expressed as $\Delta mag$) for all the available
data sets.

ID | JD | 52mas | 100mas | 200mas | 300mas | 400mas | 500mas | 600mas | 700mas | 800mas
---|---|---|---|---|---|---|---|---|---|---
HIP 15247 | 03/10/2019 |  | 7.49 | 10.08 | 11.96 | 12.9 | 12.86 | 12.68 | 13.23 | 13.94
HIP 15247 | 18/10/2019 |  | 6.04 | 9.52 | 9.82 | 10.44 | 11.66 | 11.61 | 10.59 | 12.25
HIP 15247 | 26/10/2019 | 3.89 | 7.36 | 9.9 | 12.25 | 13.32 | 13.52 | 13.1 | 12.79 | 13.46
HIP 17439 | 02/10/2019 | 5.17 | 8.03 | 11.76 | 13.92 | 14.09 | 13.95 | 14.83 | 15.26 | 14.35
HIP 21152 | 26/10/2019 | 6.09 | 7.53 | 12.13 | 14.41 | 14.01 | 14.15 | 14.49 | 14.5 | 13.83
HIP 21317 | 02/02/2018 |  | 6.85 | 10.24 | 11.03 | 11.9 | 12.25 | 11.41 | 12.29 | 11.88
HIP 71899 | 03/03/2019 |  | 7.26 | 10.75 | 12.5 | 12.68 | 13.49 | 12.81 | 13.26 | 13.24
HIP 22506 | 03/10/2019 |  | 7.88 | 11.01 | 13.88 | 13.47 | 13.59 | 13.25 | 12.66 | 10.1
GJ 3346 | 29/01/2018 |  | 7.17 | 11.55 | 12.22 | 12.11 | 12.86 | 13.03 | 12.86 | 12.72
HIP 27441 | 03/10/2018 |  | 5.54 | 9.55 | 10.7 | 11.11 | 11.07 | 11.54 | 12.65 | 12.14
HIP 28474 | 16/10/2019 | 3.36 | 7.76 | 10.16 | 11.98 | 11.73 | 11.69 | 12.33 | 10.31 | 11.44
HIP 28474 | 28/10/2019 | 3.77 | 6.47 | 10.0 | 12.05 | 12.09 | 10.96 | 13.27 | 9.44 | 12.33
HIP 29724 | 12/10/2019 | 3.91 | 8.66 | 9.88 | 10.86 | 11.41 | 11.71 | 11.97 | 12.0 | 11.8
HIP 33690 | 05/12/2019 | 6.42 | 7.07 | 11.72 | 13.96 | 14.54 | 14.58 | 14.58 | 15.04 | 14.75
HD 57852 | 14/12/2019 | 4.62 | 7.37 | 11.8 | 13.92 | 14.5 | 14.16 | 14.74 | 14.73 | 14.63
HD 60584 | 03/02/2018 |  | 6.34 | 10.35 | 10.87 | 12.68 | 11.47 | 13.02 | 11.06 | 11.82
HD 60584 | 08/10/2018 |  | 7.0 | 11.32 | 11.74 | 12.3 | 12.38 | 12.15 | 12.32 | 12.2
HD 60584 | 25/11/2018 |  | 7.24 | 10.77 | 11.41 | 11.94 | 12.62 | 13.56 | 11.99 | 12.31
HD 60584 | 16/12/2019 |  | 7.56 | 10.12 | 11.18 | 11.97 | 12.83 | 12.95 | 12.87 | 13.0
HIP 52462 | 04/01/2020 |  | 7.47 | 10.86 | 11.81 | 13.16 | 13.33 | 12.69 | 13.26 | 14.0
HIP 56153 | 02/03/2019 |  | 6.98 | 10.47 | 11.44 | 12.08 | 12.31 | 12.29 | 11.75 | 10.54
HIP 59726 | 08/01/2020 |  | 3.56 | 7.13 | 8.5 | 10.84 | 12.17 | 10.41 | 11.1 | 10.27
HIP 61804 | 22/02/2020 | 3.74 | 7.68 | 11.5 | 12.84 | 13.16 | 13.69 | 13.79 | 13.17 | 13.22
HIP 63734 | 07/02/2020 |  | 7.12 | 10.88 | 11.91 | 12.44 | 13.36 | 13.33 | 12.99 | 11.74
HIP 63862 | 04/02/2018 |  | 4.28 | 10.21 | 12.05 | 12.39 | 12.85 | 12.91 | 13.29 | 13.06
HIP 78549 | 24/03/2020 |  | 5.9 | 8.76 | 10.27 | 11.7 | 11.59 | 12.03 | 11.57 | 11.15
HIP 108912 | 04/10/2019 | 4.33 | 8.07 | 10.08 | 12.59 | 12.95 | 12.5 | 13.51 | 13.37 | 13.34
HIP 112491 | 02/10/2019 |  |  |  |  |  |  |  |  |
HIP 112581 | 04/10/2019 | 5.69 | 7.73 | 10.45 | 11.77 | 12.52 | 13.0 | 11.98 | 11.6 | 10.53
CD-69 2101 | 01/10/2017 |  | 5.65 | 9.37 | 11.18 | 11.08 | 11.69 | 12.26 | 12.32 | 12.36
HIP 116768 | 05/10/2019 | 5.33 | 7.04 | 10.92 | 12.98 | 13.23 | 14.06 | 13.49 | 14.62 | 14.52

Table 5: SPHERE astrometry and photometry for all the candidate companions
detected in our sample. Each epoch is reported separately. The last two column
show the status of the candidate and the probability of finding a background
contami t at the given separation and contrast as a function of galactic
coordinates, derived as described in Sec. 4.2.

ID | Obs. Date | rho | PA | IFS Photometry | IRDIS Photometry | Status | Bkg Prob
---|---|---|---|---|---|---|---
| (MJD) | (mas) | (°) | $\Delta Y$ | $\Delta J$ | $\Delta K_{1}$ | $\Delta K_{2}$ |  |
HIP 15247 | 58759.2772 | 810.10 $\pm$ 1.50 | 121.30 $\pm$ 0.11 |  |  | 2.02 $\pm$ 0.03 | 2.15 $\pm$ 0.12 | C1 | 1.7910-7
| 58774.2603 | 810.10 $\pm$ 1.50 | 121.30 $\pm$ 0.11 |  | 3.56 $\pm$ 0.50 | 2.15 $\pm$ 0.03 | 2.16 $\pm$ 0.14 |  |
| 58782.2219 | 808.80 $\pm$ 1.50 | 121.50 $\pm$ 0.10 |  | 3.65 $\pm$ 0.50 | 2.11 $\pm$ 0.03 | 2.34 $\pm$ 0.22 |  |
GJ 3346 | 58147.1069 | 3665.02 $\pm$ 2.27 | 348.31 $\pm$ 1.42 |  |  | 7.84 $\pm$ 1.63 | 7.79 $\pm$ 0.06 | C1 | 2.05 10-4
HIP 21152 | 58782.2921 | 422.40 $\pm$ 1.50 | 217.06 $\pm$ 0.20 | 11.65 $\pm$ 0.50 | 11.92 $\pm$ 0.50 | 10.82 $\pm$ 0.04 | 10.86 $\pm$ 0.05 | C0 | 8.17 10-7
HIP 28474 | 58772.2684 | 696.80 $\pm$ 1.50 | 75.42 $\pm$ 0.12 | 3.46 $\pm$ 0.50 | 3.75 $\pm$ 0.50 | 3.71 $\pm$ 0.03 | 3.63 $\pm$ 0.02 | C1 | 4.05 10-6
| 58784.3115 | 694.40 $\pm$ 1.50 | 75.44 $\pm$ 0.12 | 3.77 $\pm$ 0.50 | 3.61 $\pm$ 0.50 |  |  |  |
HIP 29724 | 58768.3211 | 99.90 $\pm$ 1.50 | 214.00 $\pm$ 0.86 | 5.81 $\pm$ 0.50 | 6.36 $\pm$ 0.50 | 5.63 $\pm$ 0.20 | 6.00 $\pm$ 0.70 | C0 | 6.57 10-7
HIP 33690 | 58822.246 | 3117.57 $\pm$ 1.10 | 239.87 $\pm$ 0.87 |  |  | 5.41 $\pm$ 0.01 | 7.70 $\pm$ 0.17 | B2 |
HD 57852 | 58831.2454 | 4792.45 $\pm$ 6.50 | 20.18 $\pm$ 0.30 |  |  | 20.18 $\pm$ 3.67 | 15.88 $\pm$ 1.81 | B2 |
HD 60584 CC1 | 58447.2208 | 543.00 $\pm$ 5.00 | 52.50 $\pm$ 0.50 |  | 12.70 $\pm$ 0.50 |  |  | L | 8.34 10-4
HD 60584 CC2 | 58152.244 | 4475.87 $\pm$ 5.24 | 332.00 $\pm$ 0.06 |  |  | 10.05 $\pm$ 0.01 | 10.00 $\pm$ 0.01 | B1 |
| 58399.3392 | 4459.78 $\pm$ 2.21 | 332.20 $\pm$ 0.03 |  |  | 10.41 $\pm$ 0.09 | 10.35 $\pm$ 0.06 |  |
| 58447.2208 | 4461.29 $\pm$ 1.23 | 332.51 $\pm$ 0.02 |  |  | 9.94 $\pm$ 0.04 | 10.65 $\pm$ 0.02 |  |
HIP 63734 | 58886.2739 | 555.00 $\pm$ 2.00 | 329.60 $\pm$ 0.20 | 11.26 $\pm$ 0.50 | 12.08 $\pm$ 0.50 |  |  | L | 5.30 10-5
HIP 63862 | 58153.3408 | 4815.57 $\pm$ 5.67 | 38.62 $\pm$ 0.06 |  |  | 12.72 $\pm$ 0.11 | 12.33 $\pm$ 0.45 | B2 |
HIP 71899 | 58545.3459 | 1115.91 $\pm$ 4.50 | 241.69 $\pm$ 0.05 |  |  | 3.72 $\pm$ 0.01 | 3.98 $\pm$ 0.11 | C1 | 3.39 10-6
HIP 78549 | 58932.3021 | 333.20 $\pm$ 1.50 | 183.40 $\pm$ 0.26 | 4.24 $\pm$ 0.50 | 4.68 $\pm$ 0.50 | 9.58 $\pm$ 0.65 | 12.37 $\pm$ 1.35 | C1 | 2.52 10-6
HIP 112581 | 58760.1384 | 736.80 $\pm$ 1.50 | 286.30 $\pm$ 0.12 | 4.71 $\pm$ 0.50 | 5.00 $\pm$ 0.50 | 5.48 $\pm$ 0.01 | 5.32 $\pm$ 0.01 | C0 | 2.17 10-6

Status: C0 = bound companion based on statistical arguments ; C1 = bound
companion based on additional epochs from other works; B0= background based on
statistical arguments; B1 = background based on follow-up from this work; B2 =
background based on based on additional epochs from other works; U = L = Low
SNR detection (see Sec. 4.4)

Table 6: Gaia astrometry and photometry of companions retrieved in EGDR3,
including additional companions outside SPHERE FoV. Separations and position
angles were derived using the positions from Gaia EDR3, when available.
Further details about the known systems can be found in Appendix A. The ID of
the target is reported in the first column to be consistent with the rest of
the tables in the paper. The Gaia ID, and the values of the parallax and
proper motion reported are those retrieved in EDR3 for the companions.
Although the companions of HIP 15247 and HD 129501 were detected by Gaia, no
astrometric solution was available in EDR3 (hence the blank fields).

IDA | Gaia EDR3 IDB | parallax | Proper Motion |  $\Delta$mag | separation | PA
---|---|---|---|---|---|---
|  | (mas) | RA (mas/yr) | DEC (mas/yr) | Gaia G band | (arcsec) | (°)
HIP 15247 | Gaia EDR3 3261733202649353216 |  |  |  |  | 0.84 | 120.56
HIP 24874 | Gaia EDR3 2983256662868370048 | 42.240 $\pm$ 0.035 | 182.685 $\pm$ 0.031 | 216.203 $\pm$ 0.032 | 14.331 | 3.65 | 347.98
HIP 27441 | Gaia EDR3 4805207967655791488 | 23.675 $\pm$ 0.013 | 31.712 $\pm$ 0.014 | 65.198 $\pm$ 0.014 | 12.303 | 33.98 | 113.54
HD 60584 | Gaia EDR3 5618420137803146240 | 32.792 $\pm$ 0.035 | -87.258 $\pm$ 0.016 | -11.556 $\pm$ 0.036 | 5.758 | 9.95 | 117.61
HD 57852 | Gaia EDR3 5492026740698525696 | 29.476 $\pm$ 0.449 | -31.762 $\pm$ 0.546 | 138.163 $\pm$ 0.567 | 6.465 | 9.05 | 26.72
HIP 71899 | Gaia EDR3 1241384331822285184 |  |  |  | 12.936 | 1.11 | 240.59

Table 7: Complete list of all the astrometric data for the detected candidate
companions for which more than one epoch was available, with the appropriate
references listed in the last column.

ID | Obs.Date | rho | $e_{rho}$ | PA | $e_{PA}$ | Ref.
---|---|---|---|---|---|---
| (MJD-245000) | (mas) | (mas) | (°) | (°) |
HIP 15247 | 55576.4 | 0.879 | 0.003 | 121.15 | 2.80 | Hartkopf+2012
| 55894.0 | 0.900 | 0.010 | 122.80 | 0.10 | Galicher+2016
| 55916.0 | 0.870 | 0.010 | 118.67 | 0.49 | Meshkat+2015
| 56263.9 | 0.872 | 0.006 | 121.20 | 5.70 | Tokovinin+2014
| 56936.7 | 0.844 | 0.003 | 119.80 | 2.10 | Tokovinin+2015
| 57388.0 | 0.837 | 0.001 | 120.55 | 0.02 | EDR3
| 57738.3 | 0.830 | 0.001 | 119.80 | 0.90 | Tokovinin+ 2018
| 58759.0 | 0.796 | 0.004 | 120.71 | 0.05 | This Work
| 58774.0 | 0.792 | 0.004 | 120.89 | 0.05 | This Work
| 58782.0 | 0.793 | 0.004 | 120.77 | 0.05 | This Work
GJ 3346 | 57205.5 | 3.647 | 0.001 | 347.89 | 0.02 | DR2
| 57388.0 | 3.651 | 0.001 | 347.98 | 0.02 | EDR3
| 58147.0 | 3.665 | 0.002 | 348.30 | 0.07 | This Work
HIP 28474 | 53122.0 | 0.613 | 0.003 | 61.70 | 0.20 | Chauvin+2015
| 58501.9 | 0.693 | 0.003 | 74.20 | 2.90 | Tokovinin+2020
| 58771.0 | 0.697 | 0.005 | 74.73 | 0.24 | This Work
HIP 33690 | 54842.9 | 4.479 | 0.009 | 286.20 | 0.20 | Wahhaj+2013
| 55200.6 | 4.302 | 0.009 | 282.90 | 0.20 | Wahhaj+2013
| 58832.0 | 3.117 | 0.007 | 239.85 | 0.01 | This Work
HD 57852 | 55157.0 | 3.301 | 0.020 | 148.90 | 0.30 | Chauvin+2015
| 55243.0 | 3.365 | 0.013 | 148.70 | 0.20 | Chauvin+2015
| 55592.0 | 3.465 | 0.009 | 149.80 | 0.20 | Chauvin+2015
| 58831.0 | 4.962 | 0.006 | 154.73 | 0.12 | This Work
HD 60584 | 58152.0 | 4.476 | 0.005 | 331.10 | 0.06 | This Work
| 58399.0 | 4.460 | 0.002 | 332.20 | 0.03 | This Work
| 58447.0 | 4.461 | 0.001 | 332.51 | 0.02 | This Work
HIP 63862 | 55246.0 | 4.231 | 0.016 | 28.00 | 0.20 | Chauvin+2015
| 55744.0 | 4.315 | 0.005 | 30.70 | 0.10 | Chauvin+2015
| 58153.0 | 4.815 | 0.006 | 38.62 | 0.05 | This Work
HIP 71899 | 57205.5 | 1.094 | 0.001 | 236.78 | 0.02 | DR2
| 57388.0 | 1.108 | 0.001 | 240.59 | 0.02 | EDR3
| 58545.0 | 1.116 | 0.004 | 241.69 | 0.05 | This Work
HIP 78549 | 54645.0 | 0.325 | 0.001 | 189.06 | 0.19 | Lafreniere+2014
| 58932.0 | 0.326 | 0.007 | 183.17 | 1.08 | This Work

Table 8: Summary of the characteristics of the comoving companions. If more
than one SHINE epoch was available, only the separation ($\rho$) and position
angle (PA) from the first epoch are reported, information on the single
measurements for these objects can be found in Tab. 5.
Except for GJ 3346, for which we used the values from Bonavita et al. (2020),
the masses of the primaries ($M_{A}$) were derived as described in Sec. 2.3.
The same is true for $M_{B}$(phot), which is the value of the secondary mass
obtained from the photometry, using the COND models (Baraffe et al., 2003).
$M_{B}$($\Delta\mu$) is instead the value of the secondary mass inferred using
FORECAST (see Sec. 4.4 for details).

ID | Separation | PA | $M_{A}$ |  $M_{B}$(phot) |  $M_{B}$($\Delta\mu$) | Notes
---|---|---|---|---|---|---
| (mas) | (au) | (deg) | ($M_{\odot}$) | ($M_{\odot}$) | ($M_{\odot}$) |
HIP 15247 | 810.10 $\pm$ 1.50 | 39.78 $\pm$ 0.09 | 121.30 $\pm$ 0.11 | 1.228$\pm$0.004 | 0.680$\pm$0.015 | 0.668$\pm$0.369 |
HIP 21152 | 422.40 $\pm$ 1.50 | 18.28 $\pm$ 0.07 | 217.06 $\pm$ 0.20 | 1.442$\pm$0.002 | 0.032$\pm$0.005 | 0.021$\pm$0.007 |
GJ 3346 | 3665.02 $\pm$ 2.27 | 87.07 $\pm$ 0.06 | 348.31 $\pm$ 1.42 | 0.683$\pm$0.018 | 0.580$\pm$0.010 | 0.611$\pm$0.339 | WD
HIP 28474 | 696.80 $\pm$ 1.50 | 37.71 $\pm$ 0.08 | 75.42 $\pm$ 0.12 | 0.958$\pm$0.011 | 0.139$\pm$0.038 | 0.152$\pm$0.085 |
HIP 29724 | 99.90 $\pm$ 1.50 | 6.30 $\pm$ 0.09 | 214.00 $\pm$ 0.86 | 1.044$\pm$0.001 | 0.063$\pm$0.008 | 0.067$\pm$0.021 |
HD 60584 | 543.00 $\pm$ 5.00 | 16.58 $\pm$ 0.15 | 232.50 $\pm$ 0.50 | 1.352$\pm$0.014 | 0.028$\pm$0.009 | 0.008$\pm$0.003 | Low SNR
HIP 63734 | 555.00 $\pm$ 2.00 | 30.02 $\pm$ 0.12 | 329.60 $\pm$ 0.20 | 1.211$\pm$0.006 | 0.011$\pm$0.003 | 0.032$\pm$0.020 | Low SNR
HIP 71899 | 1115.91 $\pm$ 4.50 | 50.85 $\pm$ 0.21 | 241.69 $\pm$ 0.05 | 1.178$\pm$0.012 | 0.390$\pm$0.005 | 0.393$\pm$0.218 |
HIP 78549 | 333.20 $\pm$ 1.50 | 47.52 $\pm$ 0.30 | 183.40 $\pm$ 0.26 | 2.614$\pm$0.012 | 0.284$\pm$0.064 | 0.420$\pm$0.241 |
HIP 112581 | 736.80 $\pm$ 1.50 | 28.19 $\pm$ 0.06 | 286.30 $\pm$ 0.12 | 1.091$\pm$0.003 | 0.144$\pm$0.050 | 0.062$\pm$0.035 |

## Data Availability

The data used for this work are available through the ESO Science Archive
Facility (http://archive.eso.org/cms.html).

## References

  * Andersen & Nordstrom (1983) Andersen J., Nordstrom B., 1983, A&AS, 52, 471
  * Baraffe et al. (2003) Baraffe I., Chabrier G., Barman T. S., Allard F., Hauschildt P. H., 2003, A&A, 402, 701
  * Baraffe et al. (2015) Baraffe I., Homeier D., Allard F., Chabrier G., 2015, A&A, 577, A42
  * Bell et al. (2015) Bell C. P. M., Mamajek E. E., Naylor T., 2015, MNRAS, 454, 593
  * Beuzit et al. (2019) Beuzit J. L., et al., 2019, A&A, 631, A155
  * Biller et al. (2007) Biller B. A., et al., 2007, ApJS, 173, 143
  * Biller et al. (2013) Biller B. A., et al., 2013, ApJ, 777, 160
  * Bonavita et al. (2013) Bonavita M., de Mooij E. J. W., Jayawardhana R., 2013, PASP, 125, 849
  * Bonavita et al. (2016) Bonavita M., Desidera S., Thalmann C., Janson M., Vigan A., Chauvin G., Lannier J., 2016, A&A, 593, A38
  * Bonavita et al. (2020) Bonavita M., et al., 2020, MNRAS, 494, 3481
  * Bouvier et al. (2008) Bouvier J., et al., 2008, A&A, 481, 661
  * Bowler (2016) Bowler B. P., 2016, PASP, 128, 102001
  * Bowler et al. (2020) Bowler B. P., Blunt S. C., Nielsen E. L., 2020, AJ, 159, 63
  * Bowler et al. (2021) Bowler B. P., et al., 2021, AJ, 161, 106
  * Brandt (2018) Brandt T. D., 2018, ApJS, 239, 31
  * Brandt (2021) Brandt T. D., 2021, ApJS, 254, 42
  * Brandt et al. (2019) Brandt T. D., Dupuy T. J., Bowler B. P., 2019, AJ, 158, 140
  * Burgasser & Splat Development Team (2017) Burgasser A. J., Splat Development Team 2017, in Astronomical Society of India Conference Series. pp 7–12 (arXiv:1707.00062)
  * Calissendorff & Janson (2018) Calissendorff P., Janson M., 2018, A&A, 615, A149
  * Casagrande et al. (2011) Casagrande L., Schönrich R., Asplund M., Cassisi S., Ramírez I., Meléndez J., Bensby T., Feltzing S., 2011, A&A, 530, A138
  * Chauvin et al. (2010) Chauvin G., et al., 2010, A&A, 509, A52
  * Chauvin et al. (2015) Chauvin G., et al., 2015, A&A, 573, A127
  * Chauvin et al. (2017) Chauvin G., et al., 2017, A&A, 605, L9
  * Chen et al. (2014) Chen C. H., Mittal T., Kuchner M., Forrest W. J., Lisse C. M., Manoj P., Sargent B. A., Watson D. M., 2014, ApJS, 211, 25
  * Chilcote et al. (2021) Chilcote J., et al., 2021, AJ, 162, 251
  * Chupina et al. (2006) Chupina N. V., Reva V. G., Vereshchagin S. V., 2006, A&A, 451, 909
  * Claudi et al. (2008) Claudi R. U., et al., 2008, in Proc. SPIE. p. 70143E, doi:10.1117/12.788366
  * Currie et al. (2020) Currie T., et al., 2020, ApJ, 904, L25
  * D’Orazi et al. (2011) D’Orazi V., Biazzo K., Randich S., 2011, A&A, 526, A103
  * Deacon & Kraus (2020) Deacon N. R., Kraus A. L., 2020, MNRAS, 496, 5176
  * Delorme et al. (2017) Delorme P., et al., 2017, A&A, 608, A79
  * Desidera et al. (2006) Desidera S., Gratton R. G., Lucatello S., Claudi R. U., Dall T. H., 2006, A&A, 454, 553
  * Desidera et al. (2015) Desidera S., et al., 2015, A&A, 573, A126
  * Desidera et al. (2021) Desidera S., et al., 2021, A&A, 651, A70
  * Dohlen et al. (2008) Dohlen K., et al., 2008, in Proc. SPIE. p. 70143L, doi:10.1117/12.789786
  * Dommanget & Nys (2002) Dommanget J., Nys O., 2002, VizieR Online Data Catalog, p. I/274
  * Drimmel et al. (2021) Drimmel R., Sozzetti A., Schröder K.-P., Bastian U., Pinamonti M., Jack D., Hernández Huerta M. A., 2021, MNRAS, 502, 328
  * Duchêne et al. (2013) Duchêne G., Bouvier J., Moraux E., Bouy H., Konopacky Q., Ghez A. M., 2013, A&A, 555, A137
  * Dupuy et al. (2019) Dupuy T. J., Brandt T. D., Kratter K. M., Bowler B. P., 2019, ApJ, 871, L4
  * ESA (1997) ESA 1997, VizieR Online Data Catalog, 1239, 0
  * Ertel et al. (2014) Ertel S., et al., 2014, A&A, 561, A114
  * Fontanive et al. (2019) Fontanive C., Mužić K., Bonavita M., Biller B., 2019, MNRAS, 490, 1120
  * Gagné & Faherty (2018) Gagné J., Faherty J. K., 2018, ApJ, 862, 138
  * Gagné et al. (2018) Gagné J., Roy-Loubier O., Faherty J. K., Doyon R., Malo L., 2018, ApJ, 860, 43
  * Gaia Collaboration et al. (2016) Gaia Collaboration et al., 2016, A&A, 595, A1
  * Gaia Collaboration et al. (2018) Gaia Collaboration et al., 2018, A&A, 616, A1
  * Gaia Collaboration et al. (2021) Gaia Collaboration Brown A. G. A., Vallenari A., Prusti T., de Bruijne J. H. J., et al. 2021, A&A, 649, A1
  * Galicher et al. (2016a) Galicher R., et al., 2016a, A&A, 594, A63
  * Galicher et al. (2016b) Galicher R., et al., 2016b, A&A, 594, A63
  * Galicher et al. (2018) Galicher R., et al., 2018, A&A, 615, A92
  * Golimowski et al. (2011) Golimowski D. A., et al., 2011, AJ, 142, 30
  * Grandjean et al. (2019) Grandjean A., et al., 2019, A&A, 627, L9
  * Guenther et al. (2005) Guenther E. W., Paulson D. B., Cochran W. D., Patience J., Hatzes A. P., Macintosh B., 2005, A&A, 442, 1031
  * Hartkopf et al. (2012) Hartkopf W. I., Tokovinin A., Mason B. D., 2012, AJ, 143, 42
  * Høg et al. (2000) Høg E., et al., 2000, A&A, 355, L27
  * Hogan et al. (2008) Hogan E., Jameson R. F., Casewell S. L., Osbourne S. L., Hambly N. C., 2008, MNRAS, 388, 495
  * Kalas et al. (2008) Kalas P., et al., 2008, Science, 322, 1345
  * Katoh et al. (2018) Katoh N., Itoh Y., Sato B., 2018, PASJ, 70, 60
  * Kervella et al. (2019) Kervella P., Arenou F., Mignard F., Thévenin F., 2019, A&A, 623, A72
  * Kervella et al. (2022) Kervella P., Arenou F., Thévenin F., 2022, A&A, 657, A7
  * King et al. (2003) King J. R., Villarreal A. R., Soderblom D. R., Gulliver A. F., Adelman S. J., 2003, AJ, 125, 1980
  * Kiraga (2012) Kiraga M., 2012, Acta Astron., 62, 67
  * Kuzuhara et al. (2022) Kuzuhara M., et al., 2022, arXiv, p. arXiv:2205.02729
  * Lafrenière et al. (2007) Lafrenière D., et al., 2007, ApJ, 670, 1367
  * Lafrenière et al. (2014) Lafrenière D., Jayawardhana R., van Kerkwijk M. H., Brandeker A., Janson M., 2014, ApJ, 785, 47
  * Lagrange et al. (2009) Lagrange A. M., Desort M., Galland F., Udry S., Mayor M., 2009, A&A, 495, 335
  * Langlois et al. (2013) Langlois M., Vigan A., Moutou C., Sauvage J.-F., Dohlen K., Costille A., Mouillet D., Le Mignant D., 2013, in Esposito S., Fini L., eds, Proceedings of the Third AO4ELT Conference. p. 63, doi:10.12839/AO4ELT3.13317
  * Langlois et al. (2021) Langlois M., et al., 2021, A&A, 651, A71
  * Lazzoni et al. (2020) Lazzoni C., et al., 2020, A&A, 641, A131
  * Leike et al. (2020) Leike R. H., Glatzle M., Enßlin T. A., 2020, A&A, 639, A138
  * Lodieu et al. (2014) Lodieu N., Boudreault S., Béjar V. J. S., 2014, MNRAS, 445, 3908
  * Maire et al. (2016) Maire A.-L., et al., 2016, in Proc. SPIE. p. 990834 (arXiv:1609.06681), doi:10.1117/12.2233013
  * Maire et al. (2020) Maire A. L., et al., 2020, A&A, 639, A47
  * Makarov & Kaplan (2005) Makarov V. V., Kaplan G. H., 2005, AJ, 129, 2420
  * Malkov et al. (2006) Malkov O. Y., Oblak E., Snegireva E. A., Torra J., 2006, A&A, 446, 785
  * Marigo et al. (2017) Marigo P., et al., 2017, ApJ, 835, 77
  * Marino et al. (2019) Marino S., Yelverton B., Booth M., Faramaz V., Kennedy G. M., Matrà L., Wyatt M. C., 2019, MNRAS, 484, 1257
  * Marois et al. (2014) Marois C., Correia C., Véran J.-P., Currie T., 2014, in Exploring the Formation and Evolution of Planetary Systems. pp 48–49, doi:10.1017/S1743921313007813
  * Martín et al. (2000) Martín E. L., Koresko C. D., Kulkarni S. R., Lane B. F., Wizinowich P. L., 2000, ApJL, 529, L37
  * Martín et al. (2018) Martín E. L., Lodieu N., Pavlenko Y., Béjar V. J. S., 2018, ApJ, 856, 40
  * Mesa et al. (2021) Mesa D., et al., 2021, MNRAS, 503, 1276
  * Meshkat et al. (2015) Meshkat T., Kenworthy M. A., Reggiani M., Quanz S. P., Mamajek E. E., Meyer M. R., 2015, MNRAS, 453, 2533
  * Messina et al. (2022) Messina S., Nardiello D., Desidera S., Baratella M., Benatti S., Biazzo K., D’Orazi V., 2022, A&A, 657, L3
  * Michalik et al. (2015) Michalik D., Lindegren L., Hobbs D., 2015, A&A, 574, A115
  * Netopil et al. (2008) Netopil M., Paunzen E., Maitzen H. M., North P., Hubrig S., 2008, A&A, 491, 545
  * Nielsen & Close (2010) Nielsen E. L., Close L. M., 2010, ApJ, 717, 878
  * Nielsen et al. (2019) Nielsen E. L., et al., 2019, AJ, 158, 13
  * Nielsen et al. (2020) Nielsen E. L., et al., 2020, AJ, 159, 71
  * Nordström et al. (2004) Nordström B., et al., 2004, A&A, 418, 989
  * Oelkers et al. (2018) Oelkers R. J., et al., 2018, AJ, 155, 39
  * Patience et al. (1998) Patience J., Ghez A. M., Reid I. N., Weinberger A. J., Matthews K., 1998, AJ, 115, 1972
  * Paulson et al. (2004) Paulson D. B., Cochran W. D., Hatzes A. P., 2004, AJ, 127, 3579
  * Pavlov et al. (2008) Pavlov A., Feldt M., Henning T., 2008, in Argyle R. W., Bunclark P. S., Lewis J. R., eds, Astronomical Society of the Pacific Conference Series Vol. 394, Astronomical Data Analysis Software and Systems XVII. p. 581
  * Pérez-Garrido et al. (2017) Pérez-Garrido A., Lodieu N., Rebolo R., 2017, A&A, 599, A78
  * Pérez-Garrido et al. (2018) Pérez-Garrido A., Lodieu N., Rebolo R., Chinchilla P., 2018, A&A, 620, A130
  * Phillips et al. (2020) Phillips M. W., et al., 2020, A&A, 637, A38
  * Potter et al. (2002) Potter D., Martín E. L., Cushing M. C., Baudoz P., Brandner W., Guyon O., Neuhäuser R., 2002, ApJL, 567, L133
  * Pourbaix et al. (2004) Pourbaix D., et al., 2004, A&A, 424, 727
  * Pribulla et al. (2014) Pribulla T., et al., 2014, MNRAS, 443, 2815
  * Raghavan et al. (2010) Raghavan D., et al., 2010, ApJS, 190, 1
  * Rameau et al. (2013) Rameau J., et al., 2013, A&A, 553, A60
  * Reid & Gizis (1997) Reid I. N., Gizis J. E., 1997, AJ, 114, 1992
  * Reid & Mahoney (2000) Reid I. N., Mahoney S., 2000, MNRAS, 316, 827
  * Riddle et al. (2015) Riddle R. L., et al., 2015, ApJ, 799, 4
  * Robin et al. (2012) Robin A. C., et al., 2012, A&A, 543, A100
  * Saar et al. (1990) Saar S. H., Nordstrom B., Andersen J., 1990, A&A, 235, 291
  * Schneider et al. (2017) Schneider A. C., Windsor J., Cushing M. C., Kirkpatrick J. D., Shkolnik E. L., 2017, AJ, 153, 196
  * Siegler et al. (2003) Siegler N., Close L. M., Mamajek E. E., Freed M., 2003, ApJ, 598, 1265
  * Skrutskie et al. (2006) Skrutskie M. F., et al., 2006, AJ, 131, 1163
  * Snellen & Brown (2018) Snellen I. A. G., Brown A. G. A., 2018, Nature Astronomy, 2, 883
  * Soderblom & Mayor (1993) Soderblom D. R., Mayor M., 1993, AJ, 105, 226
  * Soubiran et al. (2018) Soubiran C., et al., 2018, A&A, 616, A7
  * Squicciarini et al. (2021) Squicciarini V., Gratton R., Bonavita M., Mesa D., 2021, MNRAS, 507, 1381
  * Steiger et al. (2021) Steiger S., et al., 2021, AJ, 162, 44
  * Tokovinin (2014) Tokovinin A., 2014, AJ, 147, 86
  * Tokovinin & Briceño (2020) Tokovinin A., Briceño C., 2020, AJ, 159, 15
  * Tokovinin & Horch (2016) Tokovinin A., Horch E. P., 2016, AJ, 152, 116
  * Tokovinin et al. (2013) Tokovinin A., Hartung M., Hayward T. L., 2013, AJ, 146, 8
  * Tokovinin et al. (2018) Tokovinin A., Mason B. D., Hartkopf W. I., Mendez R. A., Horch E. P., 2018, AJ, 155, 235
  * Torres et al. (2000) Torres C. A. O., da Silva L., Quast G. R., de la Reza R., Jilinski E., 2000, AJ, 120, 1410
  * Torres et al. (2006) Torres C. A. O., Quast G. R., da Silva L., de La Reza R., Melo C. H. F., Sterzik M., 2006, A&A, 460, 695
  * Trifonov et al. (2020) Trifonov T., Tal-Or L., Zechmeister M., Kaminski A., Zucker S., Mazeh T., 2020, A&A, 636, A74
  * Vigan et al. (2010) Vigan A., Moutou C., Langlois M., Allard F., Boccaletti A., Carbillet M., Mouillet D., Smith I., 2010, MNRAS, 407, 71
  * Vigan et al. (2012) Vigan A., et al., 2012, A&A, 544, A9
  * Vigan et al. (2017) Vigan A., et al., 2017, A&A, 603, A3
  * Vigan et al. (2021) Vigan A., et al., 2021, A&A, 651, A72
  * Wahhaj et al. (2013) Wahhaj Z., et al., 2013, ApJ, 773, 179
  * Wang & Chen (2019) Wang S., Chen X., 2019, ApJ, 877, 116
  * White et al. (2007) White R. J., Gabor J. M., Hillenbrand L. A., 2007, AJ, 133, 2524
  * Wittenmyer & Marshall (2015) Wittenmyer R. A., Marshall J. P., 2015, AJ, 149, 86
  * Zhang et al. (2021) Zhang Z., Liu M. C., Best W. M. J., Dupuy T. J., Siverd R. J., 2021, ApJ, 911, 7
  * Zúñiga-Fernández et al. (2021) Zúñiga-Fernández S., et al., 2021, A&A, 645, A30
  * Zuckerman & Song (2004) Zuckerman B., Song I., 2004, ARA&A, 42, 685
  * de Zeeuw et al. (1999) de Zeeuw P. T., Hoogerwerf R., de Bruijne J. H. J., Brown A. G. A., Blaauw A., 1999, AJ, 117, 354

##  Appendix A Notes on individual targets

HIP 15247 F6V star, classified as member of Tuc-Hor in several works (e.g.,
Zuckerman & Song, 2004) It was first spatially resolved into a close pair by
Hartkopf et al. (2012). Additional astrometric observations by Tokovinin
(2014); Tokovinin & Horch (2016); Tokovinin et al. (2018); Riddle et al.
(2015); Galicher et al. (2016b); Meshkat et al. (2015) allows to constrain the
binary orbit. The secondary is also detected in GaiaEDR3. Significant RV
variability (RV rms 6.6 km/s, 3 epochs over 850 days) is reported by Nordström
et al. (2004). Single-epoch (Feb 2003) RV by White et al. (2007) (9.1$\pm$0.8
km/s) is close to the Nordström et al. (2004) mean value (7.2 km/s). The three
determinations by Zúñiga-Fernández et al. (2021) (mean 17.78$\pm$0.38 km/s,
span 16 days in July-August 2012) are instead off by more than 10 km/s with
respect to Nordström et al. (2004) mean value. These variations are larger
than the expected ones caused by the known companion, making likely that the
system is actually triple. When using BANYAN $\Sigma$, the probability of Tuc-
Hor membership largely depends on the adopted RV (high when adopting Nordström
et al. (2004) and null for Zúñiga-Fernández et al. (2021) RV). Li EW (White et
al., 2007) is more similar to that of Pleiades members, but compatible with
Tuc-Hor age considering the dispersion of individual members, while the X-ray
luminosity is close to the median value of Tuc-Hor members of similar colors.
Considering the uncertainty in the group assignment due to multiplicity, we
adopt Tuc-Hor membership, but allowing upper limit to stellar age up to the
Pleiades age. For this age, the mass of the secondary results of 0.68 Msun.

HIP 17439 = HD 23484 Field object with age indicators compatible with an age
close to the Hyades. Raghavan et al. (2010) report tentative RV variability
but the star results to have roughly constant RV from Nordström et al. (2004)
data (rms 0.1 km/s, N=4 over 2.8 years), Soubiran et al. (2018) (rms 20 m/s
from 5 CORALIE spectra over 13 years), and Wittenmyer & Marshall (2015) (rms
14 m/s from 19 UCLES/AAT spectra over 8 years), with the mean values of the
first two of these works in agreement to better than 1 km/s. The star has an
extended debris disk, spatially resolved by Herschel (Ertel et al., 2014).
Their modelling supports the presence of a two-component disk (belts at 29 and
90 au), possibly with a gap cleared by a massive planet, although a unique
very wide belt can not be ruled out. At the expected location of such
hypothetical planet ($\sim$ 60-80 au), the $\Delta\mu$ signature (albeit
marginally significant) predict a mass of about 6-8 Mjup, which would place it
below the observed detection limits for our images. RV data do not provide
significant constraints at such wide separations. The disk is not revealed in
scattered light in our SPHERE images.

HD 28736 = HIP 21152 Member of Hyades from several works in the literature and
confirmed with BANYAN $\Sigma$ analysis with updated kinematic parameters. A
new brown dwarf companion is detected in this study, as discussed in Sec. 4.5.

HD 28992 = HIP 21152 = TYC 1266-278-1  Member of Hyades from several works in
the literature and confirmed with BANYAN $\Sigma$ analysis with updated
kinematic parameters. RV monitoring from Paulson et al. (2004) (rms 21 m/s, 11
measurements, baseline 5.2 yr with HIRES/Keck) and Soubiran et al. (2018) (rms
39 m/s, 11 measurements, baseline 2.8 yr with SOPHIE/OHP) rule out massive
companions at moderately close separation. The absolute RV by Nordström et al.
(2004) agrees within error with the recent ones by Soubiran et al. (2018) and
Gaia Collaboration et al. (2018).

HIP 22506 = HD 31026 = TYC 7589-1186-1  Li EW (Torres et al., 2006), rotation
period (Kiraga, 2012), and X-ray emission are marginally compatible with the
distributions of Pleiades (125 Myr) and Argus (50 Myr) members, but
intermediate between the mean loci of these groups. There are clear
indications of RV variability (peak-to-valley 17 km/s) from sparse RV
determinations available in the literature (Nordström et al., 2004; Torres et
al., 2006; Gaia Collaboration et al., 2018). The assignment to known groups
depends on the adopted RV. We obtain high membership probability for Argus
when adopting GaiaRV or without RV, and poor match for Nordström et al.
(2004); Torres et al. (2006) RV. The expected RV to optimize the Argus
membership is very close to the mean values of the three determinations. We
then adopt the Argus with upper limit at Pleiades age $50^{+75}_{-10}$ Myr.
Our SPHERE images do not reveal any candidate. It is possible that the
$\Delta\mu$ signature is due to the unseen spectroscopic companion.

GJ 3346 = HIP 24874 = HD 34865 = TYC 5902-586-1
Star with white dwarf companion, discovered and characterized as part of the
present project. Previously published in Bonavita et al. (2020). It was
included in the sample as it appears as a young star with moderately high
activity level, due to accretion of material lost by the WD progenitor.

HIP 27441 = HD 39126 = TYC 7601-371-1 Field object. Age indicators
consistently provide an age of 250$\pm$100 Myr. The star has a wide common
proper motion companion, 2MASS J05483951-3956087, at 34" (1400 au at the
distance of the star). From colors and absolute magnitudes, the companion is
expected to be a M2 star.

HIP 28474 = HD 41071 = RT Pic The star is classified as member of Columba
association in several works and membership is confirmed by our analysis with
updated Gaiainputs. Age indicators support a young age although Li EW and
rotation period are in mild disagreement with the typical values of Tuc-Hor
and Columba members and more similar to Pleiades and AB Dor ones. For this
reason, we adopt Columba age but with upper limit at the age of the Pleiades.
The classification as eclipsing binary with 2.6 mag deep eclipses (Malkov et
al., 2006) appears spurious, as there are no indications of them in the TESS
light curve (4 sectors) and the RV results constant over decades at km/s level
(Nordström et al., 2004; Gaia Collaboration et al., 2018) and at few tens of
m/s level over three months from HARPS data. A close stellar companion was
identified by Chauvin et al. (2010) and further observed by Tokovinin &
Briceño (2020). It is also detected in our data (mass from photometry 0.16
Msun) and is the responsible of the $\Delta\mu$ signature.

HIP 29724 = HD 43976 Young field object, not associated to any known moving
group. Li EW and X ray emission are close to the mean locus of the Pleiades
while the rotation period from TESS suggests a slightly older age. A new
substellar companion is detected in this study (see Sec. 4.6 for details).

HIP 33690 = HD 53143 Star with resolved debris disk (Kalas et al., 2008). The
star is flagged as a possible member of IC2391/Argus in some literature works
(e.g., Nielsen et al., 2019). However, BANYAN analysis with updated
Gaiaparameters return 0% membership probability for this group and no
significant probability for other known MGs. Furthermore, the non detection of
Lithium (Torres et al., 2000) clearly rules out the young age of IC2391/Argus.
The Li non-detection and the other age indicators are fully compatible with an
age similar to the Hyades. The companion candidate seen in our images and
previously identified by Wahhaj et al. (2013) is a background object.

HD 57852 = HIP 35564 = HR 2813 = TYC 8132-2112-1 Bona-fide member of Carina-
Near MG, confirmed with BANYAN $\Sigma$ analysis using the updated kinematic
parameters. The star has highly significant RV variability (Andersen &
Nordstrom, 1983; Pribulla et al., 2014; Desidera et al., 2015; Gaia
Collaboration et al., 2018), although without orbital solution. Peak-to-valley
RV range for the available data is 13 km/s. The longest-period plausible
orbital solution consistent with the data yields a period of 994 d with
moderately high eccentricity. Shorter periods are also possible considering
the poor time sampling. The spectroscopic component is likely the responsible
of the $\Delta\mu$ signature and of the large RUWE in GaiaEDR3 (8.69), and it
is expected to be at a separation too close to the star to be detected in
SPHERE images. HD 57852 has a wide companion (HD 57853) at 9", which is itself
a spectroscopic binary with three components with total mass 2.4 Msun (Saar et
al., 1990; Desidera et al., 2006) The system is then a hierarchical quintuple.
The source detected at 4.9" and previously identified by Chauvin et al. (2015)
is a background object.

n Pup A = HD 60584 = TYC 6539-3802-1 Mid-F type star with a nearly twin wide
companion (n Pup B = HD 60585 at 9.9"). Katoh et al. (2018) found the primary
to an SB1 with period 366 days, eccentricity 0.49, RV semi-amplitude 12 km/s,
corresponding to a minimum mass of 0.5 Msun. This orbital solution and
variability above 1.6 km/s (peak-to-valley) are not supported by HARPS RV
(Lagrange et al., 2009; Trifonov et al., 2020). The HARPS RV variability
appears to be dominated by short-term variations (intra-night and from
contiguous nights) with limited variability on longer timescales. The star is
an X-ray source, but considering the very limited age dependence of X-ray
emission for mid-F stars we rely only on isochrone fitting for our age
estimate. The identification of a faint BD candidate, compatible with the
$\Delta\mu$ signature, is discussed in Sect. 4.7. The source at 4.4" is a
background object.

HIP 48341 = HD 85364 = HR 3899 = 6 Sex = TYC 4899-1904-1 Early type star,
identified as a possible member of UMa group by Soderblom & Mayor (1993); King
et al. (2003). Chupina et al. (2006) classified it as a member of corona
surrounding the UMa nucleus. Kinematic analysis using BANYAN returns a field
object classification. Independently on the kinematic assignment, isochrone
fitting yields an age of 660$\pm$260, formally compatible with Ursa Major. The
star has also IR excess indicating the presence of a debris disk (Chen et al.,
2014).

HIP 52462 = HD 92945 = V419 Hya Star with spatially resolved debris disk
(Golimowski et al., 2011; Marino et al., 2019). The stellar properties and the
presence of companions combining imaging, RV, and astrometric signatures were
recently investigated by Mesa et al. (2021).

HIP 59726 = HD 106489 Field object with age similar to the Hyades. The RV
results constant within 0.5 km/s from few literature measurements spanning
several decades.

HIP 61804 Young star, not associated to any known moving group. The rotation
period from TESS and chromospheric activity are similar to Pleiades members.

HIP 63734 = HD 113414 F7/F8 star, investigated by Nardiello et al., submitted
as a candidate comoving object to TOI-1807 and TOI-2048, 300 Myr old stars
both hosting transiting planets. The star results likely younger, with an
estimated age of 150 Myr from Li EW and X-ray emission. The identification of
a faint BD candidate, compatible with the $\Delta\mu$ signature, is discussed
in Sect. 4.7.

HIP 63862 = HD 113553 = TYC 8258-871-1 BANYAN $\Sigma$ yields a 53% membership
probability for Carina-Near MG. The star was not considered a candidate
members in past studies, With a field star classification and a variety of age
indicators, Vigan et al. (2017) estimated an age of 180 Myr with 120-250
limits, fully consistent with the age of Carina-Near MG. We adopt Carina-Near
MG age, with expanded age limits from indirect age indicators due to the
moderately low membership probability. Mean RVs from Nordström et al. (2004);
Torres et al. (2006); Gaia Collaboration et al. (2018) agree very well, while
Nordström et al. (2004) mentioned a marginally significant variability (rms
0.5 km/s, 11% probability of constant RV). The source at 4.4", previously
detected by Chauvin et al. (2015), is a background object.

HIP 71899 = HD 129501 = TYC 1483-1030-1 F8 star. A bright source is detected
within IRDIS field of view and is also seen (without full astrometric
solution) in Gaia Collaboration et al. (2018); Gaia Collaboration et al.
(2021). The combination of SPHERE and Gaiadata confirms its physical
association, with a mass of 0.39 Msun. Indications of the young age of the
system comes from the prominent X-ray emission (intermediate between Hyades
and Pleiades of similar color) and rotation period from KELT (Oelkers et al.,
2018), comparable to Pleiades stars although with the limited age sensitivity
expected for F type stars. Isochrone fitting, when adopting solar metallicity
is compatible with the young age from activity and with a broader range up to
3 Gyr. The sub-solar metallicity by Stromgren photometry (Casagrande et al.,
2011) (which however could be biased by stellar activity) would instead
indicate an evolved star. Finally the kinematics is slightly outside the
kinematic space of young stars. The limited amount of data (no light curve
from TESS, no high resolution spectra available in public archives) and the
impact of binarity prevents a better age determination. Therefore, we adopt
the X-ray age, keeping as upper limit the results of isochrone fitting.

HD 143600 = HIP 78549 The star is a well known recognized member of Upper Sco
association (e.g., de Zeeuw et al., 1999) and membership is confirmed by our
own check with Gaiadata. The star was discovered to be a close visual binary
(sep 0.325", $\Delta$ Ks=3.99) by Lafrenière et al. (2014). There is no
significant IR excess, while the star has a significant reddening (E(B-V) =
0.14) from comparison of observed and expected colors for the B9.5 spectral
type.

HIP 108912 All the indicators are consistent with an age intermediate between
Hyades and Pleiades, and similar to Group X. RV by Nordström et al. (2004);
Gaia Collaboration et al. (2018) are in agreement within errors.

HIP 112491 Field object; age indicators consistently suggest an age close to
that of the Hyades.

HIP 112581 Field object with age similar to the Hyades. A close candidate
(estimated mass 0.14 Msun from photometry) is identified at 0.7", very likely
a true companion considering the small projected separation and the presence
of the astrometric signature, roughly compatible with the properties of the
observed candidate.

TYC 9339-2158-1 Wide visual binary, with the primary of the system, the G1
star HIP 116063 = HD 221231 being at 36". The analysis of the age indicators
yields to an age intermediate between Hyades and Pleiades (Vigan et al.,
2017).

HIP 116768 Am star. Isochrone fitting (using the Teff calibration by Netopil
et al., 2008) indicate that the star is somewhat evolved outside main
sequence. However, the star is likely a binary (RUWE=6.3 in GaiaEDR3) so
parallax (which has a large error), magnitude, and age can be biased by
binarity. The star has a low membership probability in Argus (29.8%), in
contrast with the isochrone age.

## Acknowledgements

This research has made use of the SIMBAD database and of the VizieR catalogue
access tool operated at CDS, Strasbourg, France, and of the Washington Double
Star Catalogue maintained at the U.S. Naval Observatory. This work has made
use of data from the European Space Agency (ESA) mission Gaia
(http://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and
Analysis Consortium (DPAC,
http://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has
been provided by national institutions, in particular the institutions
participating in the Gaia Multilateral Agreement. This work has made use of
the SPHERE Data Centre, jointly operated by OSUG/IPAG (Grenoble),
PYTHEAS/LAM/CeSAM (Marseille), OCA/Lagrange (Nice), Observatoire de
Paris/LESIA (Paris), and Observatoire de Lyon/CRAL, and supported by a grant
from Labex OSUG@2020 (Investissements d’avenir – ANR10 LABX56). CF
acknowledges support from the Center for Space and Habitability (CSH). This
work has been carried out within the framework of the NCCR PlanetS supported
by the Swiss National Science Foundation. This work has been supported by the
PRIN-INAF 2019 "Planetary systems at young ages (PLATEA)" and ASI-INAF
agreement n.2018-16-HH.0. KM acknowledges funding by the Science and
Technology Foundation of Portugal (FCT), grants No. IF/00194/2015, PTDC/FIS-
AST/28731/2017, and UIDB/00099/2020. For the purpose of open access, the
authors have applied a Creative Commons Attribution (CC BY) licence to any
Author Accepted Manuscript version arising from this submission.