New Variable Stars in Auriga II

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

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

Received:   3.11.2010;   accepted:   28.01.2011
(E-mail for contact: bredfild@mail.ru, sav@surgut.ru, bs25@mail.ru)

Comments:


1. Primary minimum:HJD(TT) 2455191.296 ± 0.002. Min_II=18^m.36.

2. Primary minimum:HJD(TT) 2455275.254 ± 0.002. Min_II=17^m.93. P = 0.33285 d is also possible.

3. Min_II=17^m.85.

4. Primary minima:

HJD(TT)	±
2455275.2015	0.0007
2455306.232	0.003

Min_II=16^m.01.

5. Primary minima:

HJD(TT)	±
2455189.2551	0.0002
2455234.1884	0.0004

Min_II=17^m.93.

6. Primary minimum:HJD(TT) 2455191.255 ± 0.002. Min_II=18^m.77.

8. Infrared colors J–H = 0.350, H–K = 0.153 and J–K = 0.503 (2MASS) are consistent with the dK spectral type (Bessell and Brett 1988) and BY: classification.

9. A close pair of two stars, 2MASS 06005035+3458191 and 2MASS 06005069+3458190. The angular resulution of our telescope is insufissient to determine which of the two stars varies. Primary minimum: HJD(TT) 2455205.285 ± 0.001. Min_II=15^m.21.

10. Primary minimum: HJD(TT) 2455191.2245 ± 0.0009. Min_II=16^m.60.

11. Min_II=14^m.42.

12. Infrared colors J–H = 0.871, H–K = 0.285 and J–K = 1.156 (2MASS) are consistent with the gM spectral type (Bessell and Brett 1988) and SR classification.

13. Infrared colors J–H = 1.021, H–K = 0.300 and J–K = 1.321 (2MASS) are consistent with the gM spectral type (Bessell and Brett 1988) and SR: classification. The tabulated period is uncertain, it is longer than the time span of our observations.

Remarks:
During observations of a field in Auriga, we discovered 13 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 316 images with 5-minute exposures were obtained on JD 2455189–2455326. 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 1200-04190505 = USNO-B1.0 1251-0119138 (α = 06^h00^m32^s.51, δ = +35°11′ 08″.4, J2000, 2MASS), R₁ = 14^m.55, R₂ = 14^m.30 (USNO-B1.0). Unfiltered magnitudes were calibrated using the comparison star, assuming R_comp = 14^m.425. 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 (www.peranso.com).

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