New Variable Stars in Taurus

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

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

Received:   13.03.2010;   accepted:   18.05.2010
(E-mail for contact: bredfild@mail.ru, sav@surgut.ru, bs25@mail.ru)

Comments:


1. Min_II=18^m.83.

2. Min_II=15^m.83.

3. Primary minimum: HJD(TT) 2455131.5734 ± 0.0005. Min_II=16^m.80.

4. Infrared colors J-H=0.645, H-K=0.130 and J-K=0.775 (2MASS) are consistent with the dK spectral type (Bessell and Brett 1988) and BY classification.

5. O'Connell effect. Primary minima:

HJD(TT)	±
2455146.6091	0.0003
2455159.440	0.001
2455229.3011	0.0005
2455257.2455	0.0007

Min_II=16^m.07.

6. A close pair of two stars, not found in any catalogues separately. The angular resolution of our telescope is insufficient to determine which of the two stars varies. Primary minima:

HJD(TT)	±
2455159.5006	0.0007
2455191.424	0.002

Min_II=17^m.29.

7. Primary minima:

HJD(TT)	±
2455159.5731	0.0003
2455205.3694	0.0006

Min_II=15^m.61.

8. Primary minima:

HJD(TT)	±
2455128.5618	0.0006
2455146.6032	0.0003
2455159.4917	0.0008
2455189.4841	0.0007

Min_II=18^m.49.

Remarks:
During observations of a field in Taurus, we discovered 8 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 612 images with 5-minute exposures were obtained on JD 2455125 - 2455257. For basic reductions for dark current, flat fields, and bias, 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 1050-01424022 = USNO-B1.0 1122-0073209 ( α=04^h47^m11^s.17, δ=+22°15′ 43″.4 J2000, 2MASS); R₁=14^m.21, R₂=14^m.35 (USNO-B1.0). Unfiltered magnitudes were calibrated using the comparison star, assuming R_comp=14^m.28. 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).

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

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