Peremennye Zvezdy (Variable Stars) 40, No. 2, 2020 Received 12 April; accepted 17 April. DOI 10.24411/2221-0474-2020-10003

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CCD Observations of 164 RR Lyrae variables

Muhie T.D.^1,2, L.N. Berdnikov³, A.Yu. Kniazev^3,4,5, A.K. Dambis³

1. Astronomy and Astrophysics Research Division, Entoto Observatory and Research Centre (EORC),
   Ethiopian Space Science and Technology Institute (ESSTI), P.O.Box 33679, Addis Ababa, Ethiopia;
   tesfayedagne7@gmail.com

2. Washera Geospace and Radar Science Research Laboratory, Department of Physics, Science College,
   Bahir Dar University, P.O.Box 79, Bahir Dar, Ethiopia

3. Sternberg Astronomical Institute, Moscow State University, Universitetskij pr. 13, Moscow 119992, Russia

4. South African Astronomical Observatory, P.O. Box 9, Observatory, Cape Town, 7935 South Africa

5. Southern African Large Telescope Foundation, P.O. Box 9, Observatory, Cape Town, 7935 South Africa

The CCD observations were performed between March 16 and May 31, 2016 (JD 2457464-2457540) with the 1-m reflector of the South African Astronomical Observatory (SAAO), equipped with the Sutherland High-speed Optical Camera (Coppejans et al. 2013). We used filters of the Kron-Cousins (Cousins 1976) photometric system.

We first reduced observations obtained using "all-sky" technique exclusively during photometric nights to obtain a catalog of positions and PSF magnitudes of all objects found on the best CCD frames. We then selected, from this catalog, constant stars, which we used for differential photometry of all stars in all CCD frames including those acquired during non-photometric nights. For a complete description of the observation and reduction technique employed, see Berdnikov et al. (2011).

We acquired a total of 4660 measurements for 164 RR Lyraes, which are plotted in Figures 1-12. The phases of the observations were calculated with the light elements from GCVS-V (Samus et al. 2017). Observational uncertainties are close to 0.01 mag in all bands. The observations are available in a text file in the html version of the paper.

We will use our data to study the structure and kinematics of the Galactic halo and thick disk as well as the properties of RR Lyrae stars.

Acknowledgments: This work was supported by the Russian Foundation for Basic Research (project nos. 18-02-00890 and 19-02-00611). T.D. Muhie gratefully acknowledges the support from Ethiopian Space Science and Technology Institute (ESSTI) and Bahir Dar University. This paper uses observations made at the South African Astronomical Observatory (SAAO).

References:

Berdnikov, L.N., Kniazev, A.Yu., Sefako, R., Kravtsov, V.V., Pastukhova, E.N., Zhuiko, S.V., 2011, Astron. Rep., 55, 816

Coppejans, R., Gulbis, A.A.S., Kotze, M.M., Coppejans, D.L., Worters, H.L., Woudt, P.A., Whittal, H., Cloete, J., Fourie, P., 2013, Publ. Astron. Soc. Pacif., 125, 976

Cousins, A.W.J., 1976, Mem. RAS, 81, 25

Samus, N.N., Kazarovets, E.V., Durlevich, O.V., Kireeva, N.N., Pastukhova, E.N., 2017, Astron. Rep., 61, 80

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