New Variable Stars in Ursa Major: Area of 2°.3×4°.6, Centered at α=12h00m, δ=54°30′

E. G. Lapukhin^#1, S. A. Veselkov^#1, A. M. Zubareva^#2,3

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

Received:   9.05.2013;   accepted:   29.05.2014
(E-mail for contact: slovoktk@mail.ru)

Comments:


1. The star is present in the database of the Catalina Surveys, CSS_J115211.0+554808. The Catalina data confirm the star's type and period. Independently discovered by Palaversa et al. (2013), listed as LINEAR 2681145.

2. Independently discovered by Palaversa et al. (2013), listed as LINEAR 2686769.

4. J = 12.576, H = 12.039, K = 11.947 (2MASS).

6. Twice longer period and EW type are also possible.

7. We observed one minimum only, on JD_min = 2456374.118.

8. The star is present in the database of the Catalina Surveys, CSS_J115927.1+521224. Independently discovered by Palaversa et al. (2013), listed as LINEAR 2672279. The Catalina data confirm the star's type and period.

11. This star was discovered together with pupils of school for deaf children (Achinsk city). Independently discovered by Palaversa et al. (2013), listed as LINEAR 2992494.

12. The star is present in the database of the Catalina Surveys, CSS_J120433.0+553604. The Catalina data confirm the star's type and period. Independently discovered by Palaversa et al. (2013), listed as LINEAR 2997346.

13. Independently discovered by Palaversa et al. (2013), listed as LINEAR 3001254.

Remarks:
In March and April, 2013, we observed two adjacent fields in Ursa Major. Our observations were performed in the observatory of the Siberian State Aerospace University, in the city of Krasnoyarsk, with a Hamilton telescope (D = 400 mm, F = 915 mm), equipped with a FLI ML9000 CCD chip (3056 × 3056 pixels, pixel size 12 μm). The exposure time was 30 seconds for each frame. The size of the two fields taken together is 2°.3 × 4°.6.
All our CCD observations were obtained without a filter. The magnitudes were referred to red magnitudes of comparison stars from the USNO-A2.0 catalog (Monet et al. 1998).
We used the VaST software (Sokolovsky & Lebedev 2005) to search for new variable stars. We discovered 13 new variable stars. Periods were derived using the WinEfk software provided by Dr. V.P. Goranskij. The coordinates in the Table are from the USNO-A2.0 catalog (Monet et al. 1998). Observations for several stars can also be found in the Catalina Surveys (Drake et al. 2009).

From the editorial board: The discoveries from the LINEAR team (Palaversa et al. 2013) were reported in the VSX in August, 2014, i.e. after the submission of the present paper.

Acknowledgements: The authors wish to thank Dr. V.P. Goranskij for his efficient period-search software and Dr. Kirill Sokolovsky for providing VaST (a software package for detection of variable objects in a series of astronomical images).

References:
Drake, A.J., Djorgovski, S.G., Mahabal, A., et al., 2009, Astrophys. J., 696, 870
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 Données Astronomiques de Strasbourg, I/252
Palaversa, L., Ivezić, Ž., Eyer, L., et al., 2013, Astron. J., 146, 101
Sokolovsky, K., Lebedev, A., 2005, in 12th Young Scientists' Conference on Astronomy and Space Physics, Kyiv, Ukraine, April 19-23, 2005, eds.: Simon, A., Golovin, A., p.79