New Variable Stars Discovered at Moscow Palace of Pioneers. Part 1. Eclipsing Binaries

D. Nasonov, D. Denisenko, A. Minkovskiy, A. Gusev
State-Funded Professional Educational Institution "Vorobyevy Gory", Moscow, Russia

Received:   21.12.2023;   accepted:   23.04.2024
(E-mail for contact: dmitry.sergevich@gmail.com)

Comments:


1. = Minkovskiy 8. Eclipse on 1993-05-27 POSS-II red plate. Min II = 16^m.5 r. D = 0.18 P.

2. = Minkovskiy 6. Min II = 17^m.56 r. FUV–NUV = – 0.22 (GALEX).

3. = Minkovskiy 5. Min II = 17^m.59 r. D = 0.15 P.

4. = Minkovskiy 15. Min II = 17^m.88 r. D = 0.06 P.

5. = Minkovskiy 21. Min II = 17^m.19 r. D = 0.14 P.

6. = Minkovskiy 4. Eclipse on 1988-07-14 POSS-II blue plate. Min II = 18^m.91 r. D = 0.12 P.

7. = Minkovskiy 23. Min II = 17^m.60 g. D = 0.12 P.

8. = Minkovskiy 19. Min II = 18^m.36 g. D = 0.17 P.

9. = Minkovskiy 11. Min II = 18^m.42 r. D = 0.10 P. The variable Minkovskiy 12 from the chart will be discussed in a subsequent paper.

10. = Minkovskiy 20. D = 0.10 P.

11. = Minkovskiy 16. Min II = 17^m.63 r. D = 0.08 P.

12. = Minkovskiy 17. Min II = 17^m.19 r. D = 0.09 P.

13. = Minkovskiy 18. Min II = 18^m.26 g. D = 0.11 P.

14. = Gusev 4. ATLAS magnitudes partially contaminated by 2MASS J21224058+4935454 (V = 17^m.4; sep. 7"). D = 0.23 P. The differences of the eclipse's depth and width in different bands could not be explained so far.
The variable Gusev3 from the chart will be discussed in a subsequent paper.

Remarks:
We report the discovery of the new variable stars by the students of after-school astronomy classes of the Moscow Palace of Pioneers at Vorobyovy Gory. The new variable objects were identified during 2021–2023 in the course of the PALEO project on the digitized Palomar Sky Survey plates (PALEO stands for PALomar Extinct Objects). This paper summarizes data on 14 eclipsing variable stars. Newly found cataclysmic and pulsating variables will be reported in parts 2 and 3, respectively.

The variability of the stars was suspected from visual inspection of the DSS colored maps using SIMBAD web interface. The stars displaying either unusually blue or extremely red color on the combined POSS-II blue+red plates were suspected to be variable. Then we checked in the VSX if the objects were already known as variable stars. We inspected the Catalina Real-Time Transient Survey (Drake et al., 2009), Zwicky Transient Facility Data Release 19 (Masci et al., 2019), Pan-STARRS1 Data Release 2 (Flewelling et al., 2020) and ATLAS Forced Photometry server (Heinze et al., 2018) to find light curves of the candidates, if available. The photometric time series from those surveys were then combined using the script written by D.N. and analysed with the period search software by K. Sokolovsky. The light elements were determined using Heliocentric Julian Days (HJD) of observations. Pan-STARRS1 data for the objects will be provided upon request, the data from other surveys are given in the table. Note that abbreviations zg, zr and zi are for ZTF g-, r- and i-bands, and ac and ao are for ATLAS cyan and orange bands respectively. We provide the finder charts with the variables being near the minimal brightness.

Stars' designations in table are from USNO-B1.0 catalogue (Monet et al., 2003). The coordinates of the stars were drawn from the Gaia DR3 catalogue (Gaia Collaboration, 2023).

The authors thank Sebastián Otero for his valuable recommendations.

References:
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