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18"Peremennye Zvezdy", Prilozhenie, vol. 23, N 1 (2023)
Variable Stars Discovered at the Maidanak Observatory: Field Center a=21h50m ô=+59°00'(2000.0)
F. Khamrakulov#1'2. E. G. Lapukhin#3. O. Burkhonov#1'2. B. Satovskiy#4, A. M. Zuhareva#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)
#| Name Other Coord (J2000) Ty-P-e Max Min System Period Epoch JD) iyP-£ Sp. Comment L.Curve Find.Chart Data
1 2MASS 21494762+5903068 21 49:47.637 +59:03:06.81 EA 16.71 17.21 9.975 2459442.438 min Comm. 1 out07706 LC.pne ch07706.pne out07706.dat
2 2MASS 21495389+5917479 21 49:53.927 +59:17:47.78 EA 14.8 15.01 min Comm. 2 out04237 LC.pne ch04237.pne out04237.dat
3 2MASS 21495706+5859170 21 49:57.059 +58:59:17.12 EA 15.54 15.77 min Comm. 3 out03438 LC.pne ch03438.pne out03438.dat
4 2MASS 21501845+5919368 21 50:18.444 +59:19:36.87 EA 14.25 14.42 min Comm. 4 out03774 LC.pne ch03774.pne out03774.dat
5 2MASS 21503341+5849595 21 50:33.410 +58:49:59.41 EA 17.02 17.5 3.833 2459444.657 min Comm. 5 out00405 LC.png ch00405.pne out00405.dat
6 2MASS 21510036+5906509 21 51:00.365 +59:06:50.95 EA: 15.39 <15.7 min Comm. 6 out08312 LC.pne ch08312.pne out08312.dat
7 2MASS 21513321+5906075 21 51:33.210 +59:06:07.51 EA: 16.22 16.45 min Comm. 7 out08630 LC.png ch08630.pne out08630.dat
8 2MASS 21513430+5917039 21 51:34.282 +59:17:03.86 EA 16.89 17.40 2.821 2459443.964 min Comm. 8 out04554 LC.pne ch04554.pne out04554.dat
9 2MASS 21515214+5850243 21 51:52.135 +58:50:24.35 EA 16.17 16.70 6.012 2459446.472 min Comm. 9 out00453 LC.png ch00453.pne out00453.dat
10 2MASS 21520457+5853584 21 52:04.562 +58:53:58.40 BY: 15.58 15.64 4.9 2459442.5 max out01654 LC.pne ch01654.pne out01654.dat
11 V1059 Cep 2MASS 21520880+5904357 21 52:08.787 +59:04:35.71 EA 14.83 15.25 2.5561 2459442.939 min Comm. 11 out08495 LC.png ch08495.pne out08495.dat
12 2MASS 21533095+5912299 21 53:30.947 +59:12:29.85 EA: 15.73 16.21 min Comm. 12 out06485 LC.pne ch06485.pne out06485.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. Minjj = 17m. 3.
9. Minjj = 16m.68.
11. Minn = 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 a=21h50m, S=+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
