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"Peremennye Zvezdy", Prilozhenie, vol. 9, N 24 (2009) |
#1. Astrotel Observatory, Karachay-Cherkessia, Russia;
#2. Surgut, Russia; #3. Space Research Institute (IKI), Russian Academy of Sciences, Moscow, Russia |
ISSN 2221–0474 |
Received: 21.06.2009; accepted: 23.09.2009
(E-mail for contact: bredfild@mail.ru, sav@surgut.ru, denis@hea.iki.rssi.ru, bs25@mail.ru)
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Comments:
1. Primary minima: HJD(TT) 2454921.4391, 2454934.4677. Min II = 16.23.
2. Infrared colors J-H = 0.315, H-K = 0.063 (2MASS) are consistent with an early G spectral type (Bessell and Brett 1988). The variability type is very uncertain, we suggest one of the possibilities.
3. Infrared colors J-H = 0.534, H-K = 0.12 (2MASS) are consistent with an early K spectral type (Bessell and Brett 1988) and with the BY classification.
4. Infrared colors J-H = 0.536, H-K = 0.112 (2MASS) are consistent with an early K spectral type (Bessell and Brett 1988) and with the BY classification.
5. Min II = 14.99.
6. A close pair of stars 2MASS 17284130+0322552 and 2MASS 17284149+0322536. The angular resolution of our telescope is insufficient to determine which of the two stars varies. The coordinates in the table are for the blend of the two stars from the USNO-A2.0 catalogue.
7. Primary minimum: HJD(TT) 2454927.5215. Min II = 16.25.
8. Min II = 17.19.
9. A close pair of stars 2MASS 17292890+0329321 and 2MASS 17292891+0329360. The angular resolution of our telescope is insufficient to determine which of the two stars varies. The coordinates in the table are for the blend of the two stars from the USNO-A2.0 catalogue. Primary minimum: HJD(TT) 2454928.5213. Min II = 15.98.
10. Primary minima: HJD(TT) 2454920.4900, 2454935.5254. Min II = 14.77.
11. Primary minima: HJD(TT) 2454927.4836, 2454933.5333, 2454948.4610. Min II = 16.51.
12. Primary minima: HJD(TT) 2454920.4527, 2454942.4692, 2454948.4403. Min II = 17.46.
13. Primary minima: HJD(TT) 2454920.4503, 2454921.4351, 2454948.4393. Min II = 17.27.
14. Primary minima: HJD(TT) 2454921.5135, 2454934.4366. Min II = 13.26.
15. Maxima: HJD(TT) 2454921.5523, 2454928.5162, 2454935.4762, 2454948.4688, 2454949.4000.
16. Primary minima: HJD(TT) 2454920.5006, 2454933.4966, 2454934.4249. Min II = 17.19.
17. Primary minimum: HJD(TT) 2454928.4379. Min II = 15.26.
18. Infrared colors J-H = 0.394, H-K = 0.137 (2MASS) are consistent with an early K spectral type (Bessell and Brett 1988) and with the BY classification.Remarks:
During observations of the field of GRB 080605 (Sbarufatti et al. 2008), we discovered 18 new variable stars. Our observations were carried out at Astrotel-Caucasus observatory using the 300-mm Ritchey-Chretien telescope, equipped with an unfiltered Apogee Alta U9000 CCD camera. A total of 527 images with 5-minute exposures were obtained on JD 2454672 - 2454954. 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 GSC 0418-001697 = USNO-B1.0 0936-0304538 (17:30:50.65, +03:41:37.1, J2000; R1 = 13.39 ,R2 = 13.30). Unfiltered magnitudes were calibrated using the comparison star, assuming Rcomp = 13.345. The coordinates of the variable stars in the table were drawn from the 2MASS catalogue (Cutri et al. 2003) except for the star USNO-A2.0 0900-09912621 (missing in the 2MASS catalogue) and the stars USNO-A2.0 0900-09859517 and USNO-A2.0 0900-09884501 (see the Comments); 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 (www.peranso.com)
Acknowledgements: We would like to thank S. V. Antipin and N. N. Samus for helpful discussion.References:
Bessell, M.S., Brett, J.M., 1988, PASP, 100, 1134
Cutri, R.M., Skrutskie, M.F., van Dyk, S., et al., 2003, 2MASS All Sky Catalog of Point Sources, Centre de Donnees Astronomiques de Strasbourg, II/246
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
Sbarufatti, B., Barthelmy, S.D., Burrows, D.N., et al., 2008, GRB Coordinates Network Circular, No. 7828
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