New Variable Stars in the Field of V496 Aur

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

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

Received:   23.04.2011;   accepted:   20.07.2011
(E-mail for contact: bredfild@mail.ru, sav@surgut.ru, bs25@mail.ru)

Comments:


2. Primary minima:

HJD(TT)	±
2455520.4759	0.0006
2455521.5925	0.0002
2455537.5630	0.0005
2455563.5573	0.0003

Min_II = 15^m.56.

3. Min_II = 15^m.92.

4. The infrared colors J–H = 0.666, H–K = 0.152 and J–K = 0.818 (2MASS) are consistent with the dK spectral type (Bessell and Brett 1988) and BY: classification.

5. ELL type is also possible. Variability with P₁ = 0^d.2969 is probably caused by non-spherical shapes of the stars; variability with P₂ = 0^d.2980 is caused by a spotted photosphere region of one of the close binary's components. P₁ differing from P₂ means that, in this case, we can deal with a system whose components are not in corotation.
Primary minima:

HJD(TT)	±
2455503.5448	0.0008
2455511.5627	0.0007
2455537.4018	0.0005
2455538.5893	0.0005

Min_II = 14^m.87.

6. Min_II = 13^m.14.

7. O'Connell effect. Primary minima:

HJD(TT)	±
2455502.5442	0.0004
2455503.5074	0.0004
2455510.5678	0.0005
2455538.4928	0.0006
2455563.5337	0.0003

Min_II = 15^m.69.

Remarks:
During observations of the field of the cataclysmic variable V496 Aur, we discovered seven 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 664 images with 5-minute exposures were obtained on JD 2455503 – 2455563. For basic reductions for dark current, flat fields, bias, and for removing cosmic-ray 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 1275-06936213 = USNO-B1.0 1304-0181013 (α = 07^h28^m26^s.86, δ = +40°25′ 00″.7, J2000; 2MASS), R₁ = 13^m.87, R₂ = 14^m.50 (USNO-B1.0). Unfiltered magnitudes were calibrated using the comparison star, assuming R_comp = 14^m.185. The coordinates of the variable stars in the Table were drawn from the 2MASS catalogue (Skrutskie et al. 2006). For search for periods and epochs of extrema, we use Peranso software.

References:
Bessell, M.S., Brett, J.M., 1988, PASP, 100, 1134
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