# Catalog of variable stars in the WD 0009+501 and GRW +708247 fields based on
photometric survey data on transiting exoplanets

O. Ya. Yakovlev∗1, A. F. Valeev1,2, G. G. Valyavin1, V. N. Aitov1, G. Sh.
Mitiani1, T. A. Fatkhullin1,
G. M. Beskin1,3, A. V. Tavrov4, O. I. Korablev4, G. A. Galazutdinov2,1, V. V.
Vlasyuk1, E. V. Emelianov1,
V. V. Sasyuk3, A. V. Perkov5, S. F. Bondar†5, T. E. Burlakova1,2, S. N.
Fabrika1, I. I. Romanyuk1

1Special Astrophysical Observatory, Nizhnii Arkhyz, 2Crimean Astrophysical
Observatory, Nauchny,
3Kazan Federal University, Kazan, 4Space Research Institute, Moscow,
5Research and Production Corporation “Precision Systems and Instruments”,
Moscow
<EMAIL_ADDRESS>

Accepted by Astrophysical Bulletin, December 7, 2023

###### Abstract

We present a catalog of 150 variable stars, including 13 stars with exoplanet
candidates. 37 stars were identified as variables for the first time. As a
result of a 2.5-year photometric survey of exoplanets, we have obtained and
analyzed light curves for almost 50 thousand stars in fields around white
dwarfs WD 0009+501 and GRW +708247. Here we describe observations and data
processing, the search for variable stars, their cross-identification with
other catalogs and classification. The catalog is published in open access and
contains the primary classification of variability, light curves and their
parameters.

##  1 Introduction

The detection and study of variable stars is an accompanying line of research
in the process of searching for exoplanets by the transit method, the gist of
which can be reduced to detecting variations in the light of stars. The chance
of detecting new exoplanets increases with longer observations and larger
ﬁelds considered. Light curves of tens of millions of stars are obtained as a
result (e.g., the SuperWASP project [Norton, 2018]), spanning several months
or years. Catalogs are published and variable stars of diﬀerent types are
studied based on the data of such space- and ground-based exoplanet surveys.

For example, over the course of the initial TESS space telescope mission in
2018–2020, a catalog was published ([Fetherolf et al., 2023]) containing over
40 thousand variable stars. The light curves of about 200 thousand bright
stars $m<14^{m}$ were investigated in this survey on a time interval of
approximately 56 days for a quarter of them and 28 days for the rest. TESS
data were used to study variable A–F-type stars ([Skarka, M. et al., 2022]),
short-period pulsating hot subdwarfs ([Baran, A. S. et al., 2023]), and
eclipsing binaries ([Green et al., 2023]). A catalog of 221 variable stars
with m ¡ 15m ([Zhang et al., 2019]) was published based on the data of the
Antarctic Survey Telescope (AST3-II) of the CHESPA project.

Photometric observations are conducted at SAO RAS as part of the EXPLANATION
project ([Valyavin et al., 2022b, Valyavin et al., 2022a]) using small robotic
telescopes. Two of them are actively working at present, with another three
mounted and being prepared for operation. In order to search for exoplanet
candidates, observations of two regions with a size of about ${1.5^{\circ}}$
were carried out over the course of 2.5 years using one of these telescopes.
As a result of these observations, photometric series with a maximum duration
of 23 and 56 days were obtained for a total of almost 50 000 stars (for the
ﬁrst and second region, correspondingly).

Considering the less than 10 per cent geometric detection probability of hot
Jupiters ([Deeg and Alonso, 2018]), the best attainable accuracy of 3
${\sigma\approx 0\,.\\!\\!^{\rm m}01}$, as well as the gaps between
observations and their duration, we expect to discover based on these data no
more than twenty new exoplanet candidates. At the same time, light curves for
at least hundreds of variable stars have been obtained, including those
previously unknown, that are suitable for study.

However, such an investigation of variable stars is not a priority for the
EXPLANATION project. This work is therefore dedicated to the description of
the compiled catalog of variable stars and their initial classiﬁcation, as
well as the presentation of the light curve parameters so that these stars can
be studied later by other research groups.

The catalog is published in open access at
link111https://www.sao.ru/jet/VarStarsDB/ and will be updated in future.
Currently it contains information about 150 eclipsing, pulsating and rotating
periodic variables: the variability type, light curves of various degrees of
processing, their parameters (period, amplitude) and phase folded light
curves, as well as their data from other catalogs.

##  2 Observations and reduction

The white dwarfs WD 0009+501 (EGGR-381) and GRW +708247 (LAWD-73), studied
earlier by the authors, were selected as central ﬁeld objects. For the
observation latitude ($\phi\approx 44^{\circ}$) these stars are nonsetting
($\delta_{1}\approx 50^{\circ}$, $\delta_{2}\approx 70^{\circ}$), which is
important in an exoplanet survey for obtaining long photometric series.

The variability of EGGR-381 with a period of $P\approx 8^{h}$ and amplitude
$m\approx 0\,.\\!\\!^{\rm m}01$ is reliably known ([Valeev et al., 2015,
Antonyuk et al., 2019]). This white dwarf was chosen as a central object with
the aim of testing the detection possibility for variations of such
amplitudes, which are also typical for the maximum depth of hot Jupiter
transits ([Winn, 2010]).

The variability of GRW +708247 was studied by [Valeev et al., 2017], however,
it was not reliably conﬁrmed. The choice of this object as a central source is
based on an assumption that it hosts a transiting exoplanet.

Observations were carried out with the “Astrosib 500” robotic Ritchey-Chretien
telescope with a $D=50$ cm main mirror. Frames were obtained in cumulative
light in a ($1\,.\\!\\!^{\prime\prime}3/$pixel) scale using a CCD detector
with a 4096x4096 9-micron pixel array mounted in the central focus. The WD
0009+501 (GAIA mag. $G=14\,.\\!\\!^{\rm m}2$) ﬁeld was observed for 84 nights
from 2020/08/25 to 2021/01/21 with a 60 s exposure, and the GRW +708247
($G=13\,.\\!\\!^{\rm m}2$) ﬁeld was observed for 224 nights from 2021/02/02 to
2022/12/31 with a 40 s exposure.

The obtained frames were processed automatically by means of an algorithm of
our design using standard photometric procedures: dark subtraction and (in the
case of the second ﬁeld) ﬂatﬁelding (CCDPack, [Warren-Smith et al., 2014]),
locating the sources and their identiﬁcation in the frame with the reference
catalog (Astrometry.net, [Lang et al., 2010]), aperture photometry ([Bertin
and Arnouts, 1999]), cross-identiﬁcation of sources and construction of
instrumental light curves with their consequent calibration (CCDPack, [Astropy
Collaboration et al., 2022]).

Gaia DR3 was adopted as a reference catalog for the coordinates ([Gaia
Collaboration et al., 2016, Gaia Collaboration et al., 2022]); it was used to
compile catalogs of almost 40 and 13 thousand stars from the observed ﬁelds in
the $G\in[14\,.\\!\\!^{\rm m}5$–$19\,.\\!\\!^{\rm m}5]$ and e
$G\in[11\,.\\!\\!^{\rm m}5$–$18\,.\\!\\!^{\rm m}5]$ intervals,
correspondingly. Over the course of two surveys, photometric series for 35 183
and 12 589 stars with a length of up to 24 390 and 55 344 points were obtained
that were later investigated for variations.

Due to the fact that the quality of the photometric series was inhomogeneous,
for various reasons, the methods described were used on the light curves in
diﬀerent combinations with additional processing: varying the median level for
each night, trend subtraction, removal of intervals of low accuracy due to bad
weather conditions. The ﬁrst two procedures were applied to detect short-
period variables or long-period eclipsing stars (i.e. sources with periodic
variations that manifest at intervals shorter than $\sim 6$ hours).

Additionally, one to twenty reference stars were used for calibration in
different instances, selected according to various criteria (see [Yakovlev et
al., 2023]). Additional information about the observations and data reduction
can be found in our earlier publications ([Yakovlev et al., 2022, Yakovlev et
al., 2023, Valyavin et al., 2022a, Valyavin et al., 2022b]).

##  3 Search for variable stars

To search for variable stars we used a step-by-step approach applied multiple
times with various methods of studying the time series for variations and
diﬀerent versions of light curve processing. A criterion was worked out at
each step by which a star was either considered to be a candidate and studied
further, or rejected.

The ﬁrst method of investigating for variability consists of constructing a
dependence of the standard deviation of the light curve $\sigma$ on magnitude
$m$ ([Sokolovsky et al., 2016]). One might consider either individual nights,
or the light curve as a whole. Those curves are selected that have deviations
higher than expected for a given magnitude. They are then visually checked for
the presence of variations or, in the case of a negative result, studied
further. This method is suitable for searching for short-period or high-
amplitude variables.

The main method used in the search consists of constructing and consequently
analyzing the box least square ([Kovacs et al., 2002], [Astropy Collaboration
et al., 2022]) and Lomb–Scargle periodograms ([Lomb, 1976], [Scargle, 1982],
[VanderPlas, 2018], [Astropy Collaboration et al., 2022]). The ﬁrst algorithm
is more effective in the search for Algol-type eclipsing variables and
exoplanet transits, whereas the second method is best for other stars (with
smoothly changing light curves). Among the obtained periodograms we select
those that have maximum signal-to-noise ratios or maximum signal-to-other peak
ratios higher than some limiting value. Phase light curves are then
constructed for the selected objects for periods with the highest mathematical
signiﬁcance and their multiples, after which they are visually analyzed.

A small number of variable stars were discovered by accident during the
process of tuning the light curve creation algorithm and their calibration, as
well as in the process of selecting the reference stars. Periodograms were
then also plotted for them with the aim of determining the period and
constructing the phase light curve with subsequent testing.

##  4 Identification with other catalogs

After the used algorithms had stopped yielding new results, the stars in the
studied ﬁelds were identiﬁed with the known variable stars (or candidate
variables) from other published catalogs. In total, we considered eight
variable star catalogs presented in Table 1, as well as the exoplanet
catalog222NASA Exoplanet Archive:
https://exoplanetarchive.ipac.caltech.edu/ . Two of these (the last in Table 1
) have to records for the given coordinates and magnitude range, as is the
case with the exoplanet catalog.

Table 1:

Used catalogs of variable stars. Shown are the number of stars in the catalogs
in the ﬁelds considered and the number of those conﬁrmed based on the
investigated data  № Name Amount Link to the Table in Vizier 1 GAIA DR3
Variables 911/101 I/358/vclassre [Gaia Collaboration et al., 2022] 2 VSX
(AAVSO) 164/68 B/vsx/vsx [Watson et al., 2009] 3 ZTF 128/60
J/ApJS/249/18/table3 [Chen et al., 2020] 4 ASAS-SN 16/47 II/366/catalog
[Jayasinghe et al., 2018] 5 ZTF (suspected) 218/2 J/ApJS/249/18/table2 [Chen
et al., 2020] 6 GCVS 3/2 B/gcvs/gcvs_cat [Samus’ et al., 2017] 7 OGLE-V 0/0
J/AcA/62/219/list_var [Soszyński et al., 2012] 8 Zhang 0/0
J/ApJS/240/16/table4 [Zhang et al., 2019]

A total of 1068 conﬁrmed or candidate variables are included in the selected
catalogs in the ﬁelds considered, of which 717 are located in the ﬁrst ﬁeld,
and 351 in the second. Most (911) are candidates in the Gaia DR3 variable star
catalog (No. 1 in Table 1 ). Variability has been conﬁrmed for only
$n_{cat}=113$ of them according to our data (87 in the WD 0009+501 ﬁeld and 26
near GRW +708247).

Using the methods described above (see Section 3) a total of 124 variable
stars have been found, $n_{s}=86$ of which were already included in other
catalogs, and the remaining 37 were not. To these 123 stars we added the
remaining $n_{cat}-n_{s}=27$ stars and obtained 150 variables in total for our
catalog (Fig. 1).

Figure 1: Positions of the variable stars from the catalog in the WD 0009+501
ﬁeld (a) and GRW +708247 (b) ﬁelds.

The search for variable stars did not have a systemic nature, and we therefore
give a rough estimate for the eﬃciency of the used approach as a ratio of
$n_{s}/n_{cat}=76\%$. In this estimate we do not take into account stars that
were unknown previously or discovered by accident, and also the false negative
variables from other catalogs (falsely not conﬁrmed by the investigated data).

##  5 Classification

The classiﬁcation was carried out according to the “General Catalog of
Variable Stars” (GCVS) (Samus’ et al., 2017) and “The International Variable
Star Index” (VSX2). The variables found in the ﬁelds considered are divided
into three main classes (Fig. 2): eclipsing (a)–(d), pulsating (e)–(g),
rotating (h). The eclipsing and pulsating classes are subdivided into 4 and 3
types, correspondingly.

Figure 2: Phase folded light curve examples for variable stars: (a) Algol
(EA), (b) $\beta$ Lyrae (EB), or (c) W Ursae Majoris (EW) type eclipsing
variables; (d) stars with exoplanet candidates (EP$|$BD$|$EA); variables of
the (e) RR Lyrae (RR), (f) $\delta$ Scuti or $\gamma$ Doradus type, or SX
Phoenicis type (DSCT$|$GDOR$|$SXPHE), (g) long-period variables (LPV); (h)
rotating variables (rot).  Figure 3: Variable stars of the catalog in the
“period–amplitude” plane classiﬁed by type: eclipsing EA, EW, EB$|$EW,
EP$|$BD$|$EA; pulsating RR, DSCT$|$GDOR$|$SXPHE (designated DGS), LPV;
rotating rot, as well as a group of unambiguously unidentiﬁed types
EW$|$rot$|$DGS$|$RR (see text for description).

Three generally accepted types are isolated among the eclipsing variables (E):
Algol (EA), $\beta$ Lyrae (EB), W Ursae Majoris (EW); and, separately, stars
with exoplanet candidates (EP$|$BD$|$EA). If the presence of a transiting
exoplanet is conﬁrmed for a star, it can be classiﬁed as an EP type object.
Otherwise, if the eclipsing component is a brown dwarf, it belongs to the BD
type (isolated only in the VSX system) or the EA type, if the second component
is a star.

Three groups are isolated in the pulsating variables class: RR Lyrae (RR);
$\delta$ Scuti or $\gamma$ Doradus, or SX Phoenicis (DSCT$|$GDOR$|$SXPHE);
long-period variables (LPV) with periods longer than three days.

The VSX, ASAS-SN and ZTF catalogs also use such a classiﬁcation by type (with
the exception of the fourth type of eclipsing stars). In Gaia the eclipsing
type (E) is not subdivided into types; the RR Lyrae (RR) and solar (SL) types
are present, and also there is no distinction between the $\delta$ Scuti,
$\gamma$ Doradus and SX Phoenicis (DSCT$|$GDOR$|$SXPHE) types. Additionally,
all catalogs isolate the RS Canum Venaticorum (RS) type, which is identiﬁed
with eight stars with the numbers 15, 95, 102, 104, 129, 133, 146, 149. The
light curves that we obtained do not conﬁrm their belonging to this type (see
the light curves in Supplementary Materials).

Out of the 113 variables contained in other catalogs, 111 were already
classiﬁed, and the remaining two from catalog No. 5 (Table 1 ) were not. Based
on this information and the obtained observational data (shape, period and
amplitude of the phase curve) a decision was made with regard to which type
the star belongs to. In the case of a discrepancy between the catalogs, VSX,
ASAS-SN and ZTF were preferred due to the fact that the Gaia classiﬁcation
(unlike these catalogs) was conducted fully automatically. Using an automatic
classiﬁer (Kim and Bailer-Jones, 2016), implemented using machine learning,
did not yield signiﬁcant results. Periods $P$ and variation amplitudes $\Delta
m$ were determined for all catalog stars; they are presented in Table 2 and in
Fig. 3.

## Conclusion

A catalog of 150 stars has been compiled as a result of a study of light
curves of the stars in the WD 0009+501 and GRW +708247 ﬁelds using variation
search algorithms and variable star catalogs. It contains 109 eclipsing
variables (type E), most of which (47) are related to type EW, 38 to type EA,
11 to EB$|$EW and 13 to stars with exoplanet candidates EP$|$BD$|$EA. The
pulsating star type (Puls) applies to 18 variables, of which 2 are RR type, 11
are (DSCT$|$GDOR$|$SXPHE) and 5 are LPV. One star (WD 0009+501) is classiﬁed
as rotating (rot), and the remaining 22 belong to the inconclusively deﬁned
EW$|$rot$|$DGS$|$RR type.

We thank the anonymous reviewers for their useful comments that helped to
improve the manuscript and L. Chmyreva for translation it from Russian. The
analysis of variable objects was carried out with the support of the Russian
Science Foundation grant 23-62-10013.

Table 2: Parameters of the stars from the catalog presented in this work and their variations. In the last column the type is given for stars known from other catalogs. DGS is the abbreviation used for (DSCT$|$GDOR$|$SXPHE). Online and .csv versions are available here. Eight exoplanet candidates published in [Yakovlev et al., 2023] were noted as SOI-n.  index | GAIA DR3 source id | RA | Dec | mag G | Amp | Per | Type | Type-0
---|---|---|---|---|---|---|---|---
Class: Eclipsing |
1 | 395274812445302016 | 2.229875 | 50.453245 | 15.5 | 0.24738 | 351.289 | EA |
2 | 395223478994996608 | 2.640593 | 50.327162 | 14.9 | 0.49551 | 218.0 | EA | E
3 | 395221314331486848 | 2.811233 | 50.332251 | 14.19 | 0.17954 | 65.56 | EA | E
4 | 395193856599122560 | 3.313128 | 49.913861 | 17.49 | 0.5043 | 59.8138 | EA | E
5 | 395272579062402816 | 2.441462 | 50.430547 | 14.66 | 0.1733 | 150.2878 | EA | E
6 | 2265877140230153600 | 283.630864 | 71.075051 | 15.59 | 0.29491 | 102.68 | EA | EA
7 | 394444818601580928 | 3.555535 | 49.846449 | 15.73 | 0.26223 | 78.0296 | EA | E
8 | 393778308397569920 | 1.931906 | 50.286905 | 14.45 | 0.52032 | 37.2892 | EA | EA
9 | 395355008075442688 | 2.617854 | 50.861803 | 17.38 | 0.21355 | 42.9687 | EA | E
10 | 395224264969539584 | 2.685054 | 50.347333 | 18.36 | 0.3398 | 76.1074 | EA |
11 | 395324324828879488 | 1.969409 | 50.98153 | 17.42 | 0.29458 | 61.5569 | EA |
12 | 394459077895183104 | 3.898685 | 49.962845 | 19.02 | 0.32565 | 60.902 | EA |
13 | 2262905160300329728 | 284.364162 | 71.226466 | 16.35 | 0.19505 | 28.62 | EA | E
14 | 395201621900114176 | 3.183671 | 50.043319 | 17.56 | 0.21223 | 14.3 | EA | EA
15 | 395312779956817280 | 2.304452 | 50.967816 | 14.58 | 0.10711 | 70.5221 | EA | RS
16 | 2262840868933718528 | 286.225297 | 71.046513 | 18.14 | 0.47657 | 208.4 | EA |
17 | 395336625615598720 | 3.1509 | 50.657034 | 14.97 | 0.17602 | 66.0876 | EA |
18 | 395204095801255040 | 3.132701 | 50.022202 | 14.5 | 0.37378 | 29.5164 | EA | EA
19 | 395370160720961920 | 3.287777 | 51.039151 | 16.3 | 0.33487 | 176.34 | EA |
20 | 395249798555153408 | 2.603089 | 50.523399 | 17.05 | 0.33628 | 290.8016 | EA |
21 | 393761880145088000 | 2.228665 | 50.05279 | 18.34 | 0.62966 | 317.0946 | EA |
22 | 395334594088690304 | 3.370551 | 50.682601 | 18.55 | 0.42489 | 405.6 | EA |
23 | 393752328136796800 | 2.406077 | 49.940379 | 18.64 | 0.30118 | 28.999 | EA |
24 | 393755042556557056 | 2.286177 | 49.930757 | 13.63 | 0.30994 | 51.4729 | EA | EA
25 | 395406685123553664 | 2.286832 | 51.019033 | 15.12 | 0.08181 | 78.4668 | EA |
26 | 393727387266077696 | 2.19181 | 49.745241 | 15.34 | 0.11052 | 54.6465 | EA |
27 | 395374043371349248 | 3.189686 | 51.15151 | 18.73 | 0.3199 | 13.4886 | EA | E
28 | 394593527545967360 | 4.226079 | 50.586942 | 17.54 | 0.15319 | 34.6235 | EA |
29 | 393699452798541824 | 2.778971 | 49.7272 | 16.05 | 0.34961 | 13.3426 | EA | E
30 | 394463579019096064 | 4.19349 | 50.059788 | 17.37 | 0.48545 | 13.885 | EA | E
31 | 393764358343856512 | 2.275185 | 50.182619 | 15.61 | 0.15133 | 21.7147 | EA | E
32 | 2262828709882555264 | 286.889657 | 71.016243 | 16.11 | 0.24376 | 16.905 | EA | E
33 | 394607271444400384 | 3.919518 | 50.885796 | 15.44 | 0.52097 | 238.1 | EA |
34 | 395217118142344064 | 2.571486 | 50.254179 | 17.94 | 0.3451 | 90.9012 | EA | E
35 | 394982067472137984 | 4.250933 | 51.009383 | 13.71 | 0.16321 | 83.475 | EA | E
36 | 395246534380053760 | 2.95904 | 50.469869 | 16.83 | 0.35978 | 16.0243 | EA | E
37 | 395297008837063936 | 2.530646 | 50.562157 | 17.2 | 0.61332 | 41.4194 | EA |
38 | 2262822525129532160 | 286.921449 | 70.802437 | 15.47 | 0.51731 | 225.05 | EA | EA
39 (SOI-2) | 395239868590825472 | 3.129905 | 50.455905 | 18.87 | 0.12539 | 50.358 | EP$|$BD$|$EA |
40 (SOI-4) | 395220833295162112 | 2.794095 | 50.272619 | 17.84 | 0.05672 | 63.422 | EP$|$BD$|$EA |
41 (SOI-5) | 395229079635160320 | 3.324483 | 50.262183 | 14.92 | 0.05902 | 198.309 | EP$|$BD$|$EA |
42 (SOI-1) | 395249244499720320 | 2.625306 | 50.464983 | 18.82 | 0.13406 | 26.085 | EP$|$BD$|$EA |
43 | 394576102863768832 | 3.749979 | 50.390906 | 18.71 | 0.1788 | 64.5 | EP$|$BD$|$EA | E
44 | 394564111315029120 | 3.826784 | 50.374682 | 16.69 | 0.08168 | 200.1872 | EP$|$BD$|$EA |
45 (SOI-3) | 395281753112434304 | 2.111531 | 50.473281 | 14.26 | 0.05474 | 45.988 | EP$|$BD$|$EA |
46 (SOI-8) | 394573186584164096 | 4.004353 | 50.540019 | 16.97 | 0.12397 | 18.768 | EP$|$BD$|$EA |
47 (SOI-6) | 395282813962513536 | 1.998838 | 50.522187 | 17.98 | 0.07576 | 49.645 | EP$|$BD$|$EA |
48 (SOI-7) | 394596585565904000 | 4.138275 | 50.686119 | 18.26 | 0.12097 | 97.67 | EP$|$BD$|$EA |
49 | 394436915861885568 | 3.683293 | 49.647688 | 15.33 | 0.1968 | 49.45 | EP$|$BD$|$EA | E
50 | 2262876259464278656 | 284.434002 | 71.083422 | 18.58 | 0.1968 | 118.1 | EP$|$BD$|$EA |
№ | GAIA DR3 source id | RA | Dec | mag G | Amp | Per (days) | Type | Type-0
---|---|---|---|---|---|---|---|---
51 | 2262779919053939584 | 286.615606 | 70.313854 | 16.02 | 0.1865 | 64.85 | EP$|$BD$|$EA |
52 | 395289415334015360 | 1.998741 | 50.621772 | 14.57 | 0.18949 | 14.74 | EB$|$EW | EW
53 | 394560336042255744 | 4.206689 | 50.262103 | 14.12 | 0.34982 | 15.555 | EB$|$EW | EW$|$EB
54 | 2262857950020261120 | 285.117959 | 70.807093 | 11.48 | 0.09064 | 15.0836 | EB$|$EW | EB
55 | 2262810705379457664 | 285.709715 | 70.777887 | 17.04 | 0.1268 | 8.414 | EB$|$EW | EW
56 | 2262870147726923776 | 284.150449 | 70.883421 | 16.28 | 0.22868 | 7.341 | EB$|$EW | EW
57 | 2262479546221314176 | 284.127211 | 70.44319 | 14.09 | 0.28055 | 68.03 | EB$|$EW | EA
58 | 2262888972567506560 | 285.050036 | 71.123747 | 16.67 | 0.4579 | 10.0512 | EB$|$EW | EW
59 | 2265875456603234176 | 283.65437 | 71.059045 | 14.78 | 0.16653 | 9.846 | EB$|$EW | EB$|$EW
60 | 2262449309651289984 | 283.539658 | 70.216066 | 16.37 | 0.4483 | 13.496 | EB$|$EW | EW
61 | 2262432469083531264 | 284.324296 | 70.036215 | 11.85 | 0.30426 | 11.1316 | EB$|$EW | EW
62 | 2262403130163052928 | 286.4915 | 70.207661 | 11.81 | 0.32283 | 12.5229 | EB$|$EW | EW
63 | 395243716881546496 | 2.931151 | 50.305563 | 17.04 | 0.07926 | 6.8423 | EW | EW
64 | 395224303628713216 | 2.674422 | 50.362957 | 14.26 | 0.38475 | 7.443 | EW | EW
65 | 394486183430499072 | 3.450808 | 50.374492 | 17.87 | 0.12285 | 7.9182 | EW | EW
66 | 395218462473241088 | 2.795403 | 50.182924 | 16.29 | 0.26878 | 17.3508 | EW | EW
67 | 395255704130776960 | 2.898425 | 50.714223 | 14.95 | 0.41457 | 6.882 | EW | EW
68 | 394477391633388032 | 3.432817 | 50.183615 | 16.81 | 0.31247 | 7.7352 | EW | EW
69 | 395257632575459456 | 2.728605 | 50.685036 | 16.09 | 0.23825 | 9.9781 | EW | EW
70 | 395226120393665920 | 3.33176 | 50.111913 | 18.04 | 0.29692 | 6.9625 | EW | EW
71 | 395202760072882176 | 3.279247 | 50.087632 | 18.95 | 0.34094 | 6.421 | EW | EW
72 | 395296768318905600 | 2.462304 | 50.526814 | 16.84 | 0.17667 | 9.2266 | EW | EW
73 | 395210628452927872 | 2.741097 | 50.076362 | 16.06 | 0.12788 | 11.1212 | EW | EW
74 | 395298898622664064 | 2.494746 | 50.612826 | 17.42 | 0.36794 | 6.168 | EW | E
75 | 395198048487250688 | 3.131944 | 49.970174 | 17.34 | 0.12468 | 5.5476 | EW | EW
76 | 395263022752784128 | 2.419259 | 50.216812 | 16.66 | 0.39183 | 6.404 | EW | EW
77 | 395261442204729728 | 2.491278 | 50.140583 | 17.52 | 0.4941 | 6.2454 | EW | EW
78 | 395195918183399808 | 3.103369 | 49.882752 | 18.31 | 0.4639 | 6.967 | EW | EW
79 | 395367961697722112 | 3.282224 | 50.947198 | 17.68 | 0.31962 | 9.3532 | EW | EW
80 | 394450144360969856 | 3.48227 | 49.944036 | 15.69 | 0.35738 | 8.8098 | EW | EW
81 | 395269040009279872 | 2.192487 | 50.36224 | 17.38 | 0.5288 | 7.072 | EW | E
82 | 394598578430693888 | 3.847475 | 50.679567 | 16.49 | 0.22431 | 6.112 | EW | EW
83 | 395195819405788672 | 3.130853 | 49.855421 | 14.31 | 0.05513 | 12.4284 | EW | E
84 | 394467049352650112 | 3.846734 | 50.143194 | 17.26 | 0.43445 | 6.3745 | EW | EW
85 | 394468526820932736 | 3.874893 | 50.163183 | 18.39 | 0.41006 | 9.5022 | EW | EW
86 | 394617471990323200 | 3.634264 | 50.926918 | 17.72 | 0.07293 | 6.4 | EW |
87 | 394600743094163712 | 3.889721 | 50.76947 | 17.52 | 0.29855 | 7.338 | EW |
88 | 393765075598535296 | 2.137554 | 50.177131 | 17.17 | 0.32087 | 8.0628 | EW | E
89 | 395362842095742848 | 2.733725 | 51.04038 | 17.45 | 0.17051 | 8.8774 | EW | EW
90 | 394568170064248704 | 4.126014 | 50.427404 | 14.13 | 0.06953 | 9.0472 | EW | n/a
91 | 393777380684644480 | 2.010245 | 50.267208 | 15.85 | 0.24783 | 19.6766 | EW | EW
92 | 395310546574009344 | 2.256365 | 50.884473 | 16.91 | 0.26386 | 9.5594 | EW | E
93 | 395403798905544576 | 2.457903 | 51.016252 | 17.16 | 0.32463 | 6.4868 | EW | EW
94 | 395190905963218944 | 3.318667 | 49.730356 | 15.87 | 0.34731 | 10.4494 | EW | E
95 | 395403867625020672 | 2.444296 | 51.015019 | 14.59 | 0.08088 | 8.5068 | EW | RS
96 | 394620053267032320 | 3.777182 | 50.981245 | 17.69 | 0.58553 | 6.409 | EW | EW
97 | 395376757790700032 | 3.306434 | 51.127022 | 14.64 | 0.04435 | 10.2743 | EW |
98 | 394625134212185344 | 3.452258 | 51.102212 | 16.96 | 0.09544 | 6.3836 | EW | EW$|$S
99 | 393778892515263744 | 1.920853 | 50.338218 | 16.39 | 0.14084 | 6.8291 | EW | EW
100 | 394596791724300800 | 4.115014 | 50.732622 | 15.73 | 0.16436 | 8.0261 | EW | EW
№ | GAIA DR3 source id | RA | Dec | mag G | Amp | Per (days) | Type | Type-0
---|---|---|---|---|---|---|---|---
101 | 394625306010871296 | 3.530354 | 51.098191 | 17.93 | 0.54707 | 6.6844 | EW | EW
102 | 395365414774910848 | 2.749469 | 51.141326 | 17.84 | 0.15113 | 8.4312 | EW | RS$|$ECL
103 | 393768167977177216 | 2.051434 | 50.02236 | 19.11 | 0.25899 | 7.0498 | EW | EW
104 | 393752980972608768 | 2.234195 | 49.833612 | 16.49 | 0.0499 | 20.9756 | EW | RS
105 | 394608950775225216 | 4.009876 | 50.955858 | 17.12 | 0.19045 | 5.4978 | EW | EW
106 | 395407715915683072 | 2.230459 | 51.06545 | 15.9 | 0.15665 | 12.6474 | EW | E
107 | 394984880672072576 | 4.07643 | 51.057003 | 17.3 | 0.32304 | 8.4036 | EW | EW
108 | 2262463706381878016 | 285.023464 | 70.339249 | 14.98 | 0.10411 | 6.0866 | EW | EW
109 | 2265362053392441344 | 282.858106 | 70.260736 | 14.78 | 0.36585 | 8.624 | EW | EW
Class: Pulsating (short-period variables) |
110 | 395230557103838208 | 3.135785 | 50.225591 | 13.58 | 0.04539 | 2.79 | DGS |
111 | 395228426800132608 | 3.370289 | 50.236349 | 13.8 | 0.03664 | 2.4 | DGS | DGS
112 | 395225231341646336 | 2.586567 | 50.368908 | 14.16 | 0.02182 | 1.2 | DGS | DGS
113 | 395216637105570048 | 2.53896 | 50.215033 | 13.64 | 0.02755 | 1.7 | DGS | DGS
114 | 394475639286763776 | 3.460441 | 50.100083 | 17.05 | 0.22323 | 3.644 | DGS | DGS
115 | 393709314043417472 | 2.70691 | 49.874564 | 13.65 | 0.02332 | 2.9738 | DGS | DGS
116 | 395289621492439936 | 1.937173 | 50.621697 | 14.03 | 0.02181 | 0.85 | DGS | DGS
117 | 394602048764259840 | 4.172585 | 50.762445 | 14.36 | 0.03554 | 1.9 | DGS | DGS
118 | 2262857606422311040 | 285.228549 | 70.782716 | 14.11 | 0.0444 | 1.1234 | DGS | DGS
119 | 2265495266098115200 | 283.000759 | 70.881247 | 12.41 | 0.0298 | 1.2 | DGS | DGS
120 | 2262444052611330432 | 283.972003 | 70.085719 | 13.59 | 0.02804 | 1.2 | DGS | DGS
121 | 395244159258089472 | 2.868577 | 50.372147 | 17.89 | 1.01857 | 15.0053 | RR | RR
122 | 2262481401647182208 | 284.258035 | 70.542965 | 15.96 | 1.45256 | 11.7579 | RR | RR
Class: Eclipsing, Pulsating, or Rotating |
123 | 395234439752169344 | 3.05832 | 50.420052 | 14.25 | 0.00718 | 8.0188 | rot |
124 | 395233031002910848 | 3.074812 | 50.355225 | 15.54 | 0.00684 | 16.254 | EW$|$rot$|$DGS$|$RR | DGS
125 | 395241513558355968 | 3.145331 | 50.510285 | 18.58 | 0.11171 | 14.02 | EW$|$rot$|$DGS$|$RR |
126 | 395247148555693952 | 2.826295 | 50.482282 | 18.72 | 0.10756 | 31.7477 | EW$|$rot$|$DGS$|$RR |
127 | 395247285994643456 | 2.784514 | 50.477077 | 17.78 | 0.06658 | 5.703 | EW$|$rot$|$DGS$|$RR | EW
128 | 395247698311551744 | 2.828034 | 50.535027 | 18.73 | 0.13324 | 11.54 | EW$|$rot$|$DGS$|$RR | EW
129 | 395229487649686144 | 3.257887 | 50.272096 | 18.82 | 0.10328 | 8.6011 | EW$|$rot$|$DGS$|$RR | RS
130 | 395219248447600640 | 2.743739 | 50.244472 | 17.76 | 0.04376 | 15.9492 | EW$|$rot$|$DGS$|$RR |
131 | 395222169025392000 | 2.665364 | 50.269477 | 19.1 | 0.19956 | 8.3 | EW$|$rot$|$DGS$|$RR | EW
132 | 395341225518297600 | 3.346583 | 50.765682 | 18.34 | 0.07729 | 7.5188 | EW$|$rot$|$DGS$|$RR | EW$|$DGS
133 | 394481613585244928 | 3.720843 | 50.307102 | 17.01 | 0.07133 | 7.3288 | EW$|$rot$|$DGS$|$RR | RS$|$DGS
134 | 395265363517361024 | 2.367273 | 50.322496 | 17.14 | 0.15709 | 36.755 | EW$|$rot$|$DGS$|$RR | SL
135 | 395278347196623488 | 2.198794 | 50.603909 | 18.42 | 0.17723 | 5.79 | EW$|$rot$|$DGS$|$RR | E
136 | 394599196905954432 | 3.882717 | 50.732298 | 14.15 | 0.02923 | 27.5746 | EW$|$rot$|$DGS$|$RR | DGS
137 | 395289788989565440 | 1.929221 | 50.659614 | 18.31 | 0.11733 | 7.5378 | EW$|$rot$|$DGS$|$RR | EW
138 | 394984743233106048 | 4.069788 | 51.040912 | 17.98 | 0.10494 | 7.2828 | EW$|$rot$|$DGS$|$RR | EW
139 | 394429769036291840 | 4.011307 | 49.742144 | 13.54 | 0.18438 | 13.1884 | EW$|$rot$|$DGS$|$RR | EW$|$RR
140 | 2262865337363426688 | 284.555622 | 70.751203 | 14.37 | 0.03469 | 27.419 | EW$|$rot$|$DGS$|$RR | n/a
141 | 2262491773992539008 | 283.966466 | 70.67798 | 18.13 | 0.13379 | 9.874 | EW$|$rot$|$DGS$|$RR | EW
142 | 2262485486160392832 | 283.983567 | 70.610705 | 17.84 | 0.07613 | 19.87 | EW$|$rot$|$DGS$|$RR | BY
143 | 2262828946104484608 | 286.792306 | 71.022917 | 16.84 | 0.10555 | 5.534 | EW$|$rot$|$DGS$|$RR | EW
144 | 2262444739806093696 | 283.857291 | 70.092501 | 17.02 | 0.06864 | 6.516 | EW$|$rot$|$DGS$|$RR | EW
145 | 2262430136917524352 | 284.348247 | 69.940137 | 19.99 | 0.23023 | 5.76 | EW$|$rot$|$DGS$|$RR |
Class: Pulsating (long-period variables) |
146 | 394576622557648128 | 3.61672 | 50.394126 | 14.57 | 0.18479 | 771.36 | LPV | RS
147 | 394475845441467648 | 3.441362 | 50.133345 | 19.4 | 0.08073 | 79.0 | LPV |
148 | 395350644388701312 | 2.792577 | 50.775497 | 16.24 | 0.05701 | 330.72 | LPV | SL
149 | 2262855201241187968 | 284.889344 | 70.810036 | 16.7 | 0.0853 | 403.5 | LPV | BY$|$RS
150 | 2262438898650595840 | 284.492419 | 70.112149 | 13.78 | 0.1333 | 150.6 | LPV | BY

## References

  * [Antonyuk et al., 2019] Search for and Study of Photometric Variability of Magnetic White Dwarfs WD 2047+372 and WD 0009+501.  Astrophysical Bulletin, 74(2).
  * [Astropy Collaboration et al., 2022] The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package.  Astrophys. J., (2):167.
  * [Baran, A. S. et al., 2023] Short-period pulsating hot-subdwarf stars observed by TESS - I. Southern ecliptic hemisphere.  A&A, 669:A48.
  * [Bertin and Arnouts, 1999] SExtractor: Software for source extraction.  Astron. and Astrophys. Suppl.
  * [Chen et al., 2020] The Zwicky Transient Facility Catalog of Periodic Variable Stars.  The Astrophysical Journal Supplement Series, 249(1):18.
  * [Deeg and Alonso, 2018] Transit Photometry as an Exoplanet Discovery Method.  In Handbook of Exoplanets, pages 633–657. Springer International Publishing.
  * [Fetherolf et al., 2023] Variability Catalog of Stars Observed during the TESS Prime Mission.  The Astrophysical Journal Supplement Series, 268(1):4.
  * [Gaia Collaboration et al., 2016] The Gaia mission.  Astron. and Astrophys.
  * [Gaia Collaboration et al., 2022] Gaia Data Release 3: Summary of the content and survey properties.  arXiv e-prints astro-ph:2208.00211.
  * [Green et al., 2023] 15 000 ellipsoidal binary candidates in TESS: Orbital periods, binary fraction, and tertiary companions.  Monthly Notices of the Royal Astronomical Society, 522(1):29–55.
  * [Jayasinghe et al., 2018] The ASAS-SN catalogue of variable stars I: The Serendipitous Survey.  MNRAS, 477(3):3145–3163.
  * [Kovacs et al., 2002] A box-fitting algorithm in the search for periodic transits.  Astron. and Astrophys.
  * [Lang et al., 2010] Astrometry.net: Blind astrometric calibration of arbitrary astronomical images.  Astron. J.
  * [Lomb, 1976] Least-squares frequency analysis of unequally spaced data.  Astrophysics and Space Science.
  * [Norton, 2018] A Zooniverse Project to Classify Periodic Variable Stars from SuperWASP.  Research Notes of the AAS, 2(4):216.
  * [Samus’ et al., 2017] General catalogue of variable stars: Version GCVS 5.1.
  * [Scargle, 1982] Studies in astronomical time series analysis. II. Statistical aspects of spectral analysis of unevenly spaced data. .  Astrophysical Journal, 263:835–853.
  * [Skarka, M. et al., 2022] Periodic variable A-F spectral type stars in the northern TESS continuous viewing zone - I. Identification and classification.  A&A, 666:A142.
  * [Sokolovsky et al., 2016] Comparative performance of selected variability detection techniques in photometric time series data.  Monthly Notices of the Royal Astronomical Society, 464(1):274–292.
  * [Soszyński et al., 2012] The Optical Gravitational Lensing Experiment. Gaia South Ecliptic Pole Field as Seen by OGLE-IV.  Acta Astronomica, 62(3):219–245.
  * [Valeev et al., 2015] Detection of regular low-amplitude photometric variability of the magnetic dwarf WD0009+501. On the possibility of photometric investigation of exoplanets on the basis of 1-meter class telescopes of the special and crimean astrophysical observatories.  Astrophysical Bulletin, pages 318–327.
  * [Valeev et al., 2017] Search for and study of photometric variability in magnetic white dwarfs.  Astrophysical Bulletin, 72(4).
  * [Valyavin et al., 2022a] EXPLANATION: Exoplanet and Transient Events Investigation Project.  Astrophysical Bulletin, 77(4).
  * [Valyavin et al., 2022b] EXPLANATION: Exoplanet and Transient Event Investigation Project. Optical Facilities and Solutions.  Photonics, 9(12).
  * [VanderPlas, 2018] Understanding the Lomb–Scargle Periodogram.  The Astrophysical Journal Supplement Series, 236(1):16.
  * [Warren-Smith et al., 2014] CCDPACK: CCD Data Reduction Package.
  * [Watson et al., 2009] AAVSO International Variable Star Index VSX (Watson+, 2006-2010).  VizieR Online Data Catalog.
  * [Winn, 2010] Transits and Occultations.  arXiv: Earth and Planetary Astrophysics.
  * [Yakovlev et al., 2022] Exoplanet two square degree survey with SAO RAS robotic facilities.  Front. Astron. Space Sci.
  * [Yakovlev et al., 2023] Eight Exoplanet Candidates in SAO Survey.  Astrophysical Bulletin, 78(1).
  * [Zhang et al., 2019] Exoplanets in the Antarctic Sky. I. The First Data Release of AST3-II (CHESPA) and New Found Variables within the Southern CVZ of TESS.  The Astrophysical Journal Supplement Series, 240(2):16.