Four New Variable Stars in Ursa Major

S. A. Veselkov^#1, E. G. Lapukhin^#1, S. V. Antipin^#2,3, N. N. Samus^#3,2

#1. Siberian State Aerospace University, Krasnoyarsk, Russia; #2. Sternberg Astronomical Institute, Lomonosov Moscow State University, Moscow, Russia; #3. Institute of Astronomy, Russian Academy of Sciences, Moscow, Russia

Received:   24.06.2011;   accepted:   30.12.2011
(E-mail for contact: slovoktk@mail.ru)

Comments:


1. MinII = 15.31.

2. MinII = 14.51.

3. MinII = 15.23. Slight O'Connell effect.

4. MinII = 12.50. The NSVS data confirm EA-type variability of the star. The star in the NSVS database: ID2672492 and ID5052816.

Remarks:
From March 05 till April 25, 2011, we obtained unfiltered CCD observations of a field in Ursa Major. Our observations were performed in the city of Krasnoyarsk with a Hamilton telescope (D = 400 mm, F = 915 mm) equipped with an FLI ML9000 CCD chip (3056x3056 pixels, pixel size 12 μm). The magnitudes were referred to red magnitudes of comparison stars from the USNO-A2.0 catalog (Monet et al. 1998). The limiting magnitude of these data is about 16^m, due to light pollution in a large city and transparency problems. MaxImDL software was used for photometry.

We have started using these observations for search for new variable stars. Four new eclisping variable stars could be discovered and studied. Our search for variable stars made use of the C-Munipack package. To search for periods, we applied WinEfk software provided by V.P. Goranskij.

Acknowledgements: The authors wish to thank Dr. V.P. Goranskij for providing his efficient period-search software. E. Lapukhin is grateful to N.Virnina for her assistance and discussion of options of the C-Munipack package.

References:
Monet, D., Bird, A., Canzian, B., et al., 1998, USNO-A2.0, A Catalog of Astrometric Standards (U.S. Naval Observatory, Washington, DC), Centre de Donnees Astronomiques de Strasbourg, I/252