New Variable Stars in the Field of V2335 Oph

T. Kryachko^#1, A. Samokhvalov^#2, B. Satovskiy^#1

#1. Astrotel Observatory, Karachay-Cherkessia, Russia; #2. Surgut, Russia

Received:   27.12.2010;   accepted:   7.04.2011
(E-mail for contact: bredfild@mail.ru, sav@surgut.ru, bs25@mail.ru)

Comments:


1. Period 0^d.2948 is also possible. Min_II = 18^m.08.

2. Min_II = 19^m.06.

3. Infrared colors J–H = 0.626, H–K = 0.153, J–K = 0.779 (2MASS) are consistent with the dK spectral type (Bessell and Brett 1988) and BY classification.

4. Periods 0^d.24130 or 0^d.27448 are also possible. Primary minimum: HJD(TT) 2455502.1597 ± 0.0008. Min_II = 17^m.40.

5. Period 0^d.32572 and ELL type are also possible.

6. O'Connell effect. Primary minimum: HJD(TT) 2455438.2338 ± 0.0006. Min_II = 13^m.21:.

7. Min_II = 17^m.63:.

8. Maxima:

HJD(TT)	±
2455438.235	0.001
2455502.1611	0.0005

9. A close pair of two stars: USNO-A2.0 0900-11502589 and a faint star, not presented in any catalogues. USNO-A2.0 0900-11502589 varies.

10. O'Connell effect. Primary minimum: HJD(TT) 2455434.241 ± 0.001. Min_II = 16^m.82:.

11. Periods 0^d.05010 and 0^d.05274 are also possible. Maxima:

HJD(TT)	±
2455437.2556	0.0006
2455438.2541	0.0008

12. A close pair of two stars not presented in any catalogues separately. Primary minimum: HJD(TT) 2455502.143 ± 0.002. Min_II = 13^m.40.

13. Periods 0^d.3190 or 0^d.3797 are also possible. Min_II = 15^m.65.

Remarks:
During observations of the field of the cataclysmic variable V2335 Oph, we discovered fourteen new variable stars. Our observations were carried out at the Astrotel-Caucasus observatory using the 300-mm Ritchey-Chretien telescope, equipped with an unfiltered Apogee Alta U9000 CCD camera. A total of 172 images with 5-minute exposures were obtained on JD 2455358–2455513. For basic reductions for dark current, flat fields, bias, and for removing cosmic rays hits we used IRAF routines. For search and photometry of new variable stars, we applied VaST software by Sokolovsky and Lebedev (2005). The comparison star was USNO-A2.0 0900-11460273 = USNO-B1.0 0950-0327798 (α=18^h04^m33^s.51, δ=+05°05′ 43″.8, J2000; 2MASS), R₁ = 14^m.20, R₂ = 14^m.49 (USNO-B1.0). Unfiltered magnitudes were calibrated using the comparison star, assuming R_comp = 14^m.345. The coordinates of the variable stars in the table were drawn from the 2MASS catalogue (Skrutskie et al. 2006) except for the stars USNO-A2.0 0900-11358267 and USNO-A2.0 0900-11543547; their coordinates were drawn from the USNO-A2.0 catalogue (Monet et al. 1998). For search for periods and epochs of extrema, we use Peranso software.

Acknowledgements: We would like to thank S. V. Antipin for helpful discussion.

References:
Bessell, M.S., Brett, J.M., 1988, PASP, 100, 1134
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
Skrutskie, M.F., Cutri, R.M., Stiening, R., et al., 2006, AJ, 131, 1163
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