Peremennye Zvezdy

Article in PDF
"Peremennye Zvezdy",
Prilozhenie
,
vol. 23, N 1 (2023)

Variable Stars Discovered at the Maidanak Observatory: Field Center α=21h50m δ=+59°00′(2000.0)

F. Khamrakulov#1,2, E. G. Lapukhin#3, O. Burkhonov#1,2, B. Satovskiy#4, A. M. Zubareva#5,6, R. Karimov#1, B. Khafizov#1
#1.Astronomical Institute of the Uzbekistan Academy of Sciences, Tashkent, Uzbekistan;
#2.Samarkand State University, Samarkand, Uzbekistan;
#3.Reshetnev Siberian State University of Science and Technology, Krasnoyarsk, Russia;
#4.State Space Corporation "Roscosmos", Moscow, Russia;
#5.Institute of Astronomy, Russian Academy of Sciences, Moscow, Russia;
#6.Sternberg Astronomical Institute, Lomonosov Moscow State University, Moscow, Russia.

ISSN 2221–0474 DOI: 10.24412/2221-0474-2023-1-1

Received:   4.03.2023;   accepted:   28.04.2023
(E-mail for contact: slovoktk@mail.ru)


#NameOtherCoord (J2000)TypeMaxMinSystemPeriodEpoch (JD)typeSpCommentL.CurveFind.ChartData
1 2MASS 21494762+590306821:49:47.637 +59:03:06.81EA16.7117.21 9.9752459442.438min Comm. 1out07706_LC.pngch07706.pngout07706.dat
2 2MASS 21495389+591747921:49:53.927 +59:17:47.78EA:14.815.01   min Comm. 2out04237_LC.pngch04237.pngout04237.dat
3 2MASS 21495706+585917021:49:57.059 +58:59:17.12EA:15.5415.77   min Comm. 3out03438_LC.pngch03438.pngout03438.dat
4 2MASS 21501845+591936821:50:18.444 +59:19:36.87EA:14.2514.42   min Comm. 4out03774_LC.pngch03774.pngout03774.dat
5 2MASS 21503341+584959521:50:33.410 +58:49:59.41EA17.0217.5 3.8332459444.657min Comm. 5out00405_LC.pngch00405.pngout00405.dat
6 2MASS 21510036+590650921:51:00.365 +59:06:50.95EA:15.39<15.7   min Comm. 6out08312_LC.pngch08312.pngout08312.dat
7 2MASS 21513321+590607521:51:33.210 +59:06:07.51EA:16.2216.45   min Comm. 7out08630_LC.pngch08630.pngout08630.dat
8 2MASS 21513430+591703921:51:34.282 +59:17:03.86EA16.8917.40 2.8212459443.964min Comm. 8out04554_LC.pngch04554.pngout04554.dat
9 2MASS 21515214+585024321:51:52.135 +58:50:24.35EA16.1716.70 6.0122459446.472min Comm. 9out00453_LC.pngch00453.pngout00453.dat
10 2MASS 21520457+585358421:52:04.562 +58:53:58.40BY:15.5815.64 4.92459442.5max  out01654_LC.pngch01654.pngout01654.dat
11V1059 Cep2MASS 21520880+590435721:52:08.787 +59:04:35.71EA14.8315.25 2.55612459442.939min Comm. 11out08495_LC.pngch08495.pngout08495.dat
12 2MASS 21533095+591229921:53:30.947 +59:12:29.85EA:15.7316.21   min Comm. 12out06485_LC.pngch06485.pngout06485.dat

Comments:


1. MinII = 17m.28.

2. It was not possible to determine the period because only one minimum was observed. JDmin = 2459446.227.

3. It was not possible to determine the period because only one minimum was observed. JDmin = 2459447.390.

4. It was not possible to determine the period because only one minimum was observed. JDmin = 2459450.191.

5. Twice longer period is possible.

6. It was not possible to determine the period because only one minimum was observed.

7. It was not possible to determine the period because only one minimum was partially covered with observations. JDmin = 2459446.175.

8. MinII = 17m.3.

9. MinII = 16m.68.

11. MinII = 15m.22. The orbit of the star is possibly slightly eccentric.

12. It was not possible to determine the period because only one minimum was observed. JDmin = 2459451.287.

Remarks:
We present the results of searching for variable stars in a field in Cepheus with the center α=21h50m, δ=+59°00′ (2000.0). 11 stars from our sample are not mentioned as variables in the available star databases: GCVS (Samus et al. 2017), VSX, ZTF (Chen et al. 2020), and ASAS-SN Variable Stars Database. V1059 Cep was discovered by Lapukhin, Veselkov, and Zubareva (2015). We have monitoreded the star in order to improve the light curve. The coordinates were extracted from Gaia DR3 (Gaia Collaboration 2022).

Observations were carried out at the Maidanak Astronomical Observatory of the Ulugh Beg Astronomical Institute (UBAI) of the Academy of Sciences of the Republic of Uzbekistan (Ehgamberdiev 2018) using the 0.5-m AMT-1 telescope with Mathis Instruments MI-750/1000 equatorial fork mount equipped with an Apogee Alta U16M (4K×4K) CCD camera. The physical size of a CCD pixel is 9 microns. We used 2×2 binning, which corresponds to 0.907′′/pixel, and the field of view of 30.9′×30.9′. The exposure times were 120 seconds in the Bessel R filter. The temperature of the camera was set to –20°C. Calibration images: bias, dark and flat field were also obtained for each observational date. Observations were obtained during the period from August 15 to 26, 2021 (JD 2459442.3 – 2459452.2).

The VaST (Variability Search Toolkit) software package (Sokolovsky & Lebedev 2018) was used to reveal the brightness variability. The periods of brightness changes were determined by the Lafler-Kinman method in the LK program written by E. G. Lapukhin & A.V. Konovalchikov (private communication).

References:
Chen, X., Wang, S., et al., 2020, Astron. J. Suppl. Ser., 249, 18
Ehgamberdiev, Sh., 2018, Nature Astronomy, 2, 349
Gaia Collaboration, 2022, arXiv:2208.00211
Lapukhin, E. G., Veselkov, S. A., Zubareva, A. M., 2015, Perem. Zvezdy Prilozh., 15, 8
Samus, N. N., Kazarovets, E. V., Durlevich, O. V., Kireeva, N. N., Pastukhova, E. N., 2017, Astron. Rep., 61, No. 1, 80
Sokolovsky, K. V., Lebedev, A. A., 2018, Astron. and Computing, 22, 28



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