Comments:
1. Primary minimum: HJD(TT) 2455450.3047 ± 0.0001. MinII = 14m.29.
3. A close pair of stars: 2MASS 18370480+0914472 and 2MASS 18370454+0914489;
2MASS 18370480+0914472 varies. MinII = 17m.15.
4. A close pair of stars: 2MASS 18370536+0930434 and 2MASS 18370524+0930382;
2MASS 18370524+0930382 varies. Type RRC and period 0d.21753 are also possible.
MinII = 15m.46.
5. A close pair of stars: 2MASS 18371343+0945095 and 2MASS 18371322+0945131;
2MASS 18371322+0945131 varies. Primary minimum: HJD(TT) 2455438.315 ± 0.001.
MinII
= 16m.41.
6. MinII is fainter than 17m.03.
7. MinII = 16m.34:.
8. MinII = 17m.54.
9. A close triplet of stars: USNO-A2.0 0975-12393204 and two
faint stars, not present in any catalogues separately; USNO-A2.0 0975-12393204
varies.
MinII = 15m.74.
10. MinII = 19m.09:.
11. Primary minimum: HJD(TT) 2455496.1676 ± 0.0008. MinII = 16m.98.
12. O'Connell effect. Primary minima:HJD(TT) | ± |
2455439.3367 | 0.0005 |
2455450.2928 | 0.0007 |
MinII
= 15m.90.
13. MinII = 15m.09.
14. A close pair of stars with equal brightness not found in any catalogues
separately. The light curve shape varies, presumably because of spot activity.
Type RRC and period 0d.2746 are also possible. MinII = 14m.09.
15. Infrared colors J–H = 0.960, H–K = 0.269 and J–K = 1.229
(2MASS) are consistent
with the M spectral type (Bessell and Brett 1988) and SR: classification.
16. Infrared colors J–H = 0.990, H–K = 0.315 and J–K = 1.305
(2MASS) are consistent
with the M spectral type (Bessell and Brett 1988) and SR: classification.
17. Primary minimum: HJD(TT) 2455495.1669 ± 0.0004. MinII = 14m.49.
19. A close pair of stars with equal brightness not found in any catalogues
separately.
20. MinII = 17m.35.
21. MinII = 14m.14.
22. Primary minimum: HJD(TT) 2455439.321 ± 0.001. MinII = 16m.41.
23. Primary minimum: HJD(TT) 2455496.1764 ± 0.0006. MinII = 16m.63.
25. O'Connell effect. Primary minimum: HJD(TT) 2455440.3649 ± 0.0008. MinII
= 13m.62.
27. A close triplet of stars: USNO-A2.0 0975-12500769, 2MASS
18390008+0957365 and a faint star, not found in any catalogues. MinII
= 16m.80.
28. MinII = 18m.27.
29. O'Connell effect. MinII = 16m.23.
31. A close pair of stars: 2MASS 18391835+0956282 and 2MASS 18391860+0956266;
2MASS 18391835+0956282 varies.
32. Infrared colors J–H = 0.627, H–K = 0.262 and J–K = 0.889
(2MASS) are consistent
with the K spectral type (Bessell and Brett 1988) and BY: classification.
33. MinII is fainter than 16m.01.
34. Maxima:HJD(TT) | ± |
2455439.356 | 0.001 |
2455495.1908 | 0.0002 |
35. Maxima:HJD(TT) | ± |
2455438.3228 | 0.0006 |
2455495.1886 | 0.0006 |
37. A close pair of stars with equal brightness not found in any catalogues
separately. MinII = 15m.28.
38. MinII = 19m.05.
39. A close pair of stars: 2MASS 18394906+1003199 and 2MASS 18394918+1003154;
2MASS 18394918+1003154 varies. MinII = 17m.00:.
40. A close pair of stars: 2MASS 18395488+0913386 and 2MASS 18395504+0913431;
2MASS 18395488+0913386 varies.
41. A close pair of stars: USNO-A2.0-0975-12561702 and a faint star, not found
in any catalogues. Primary minimum: HJD(TT) 2455439.3525 ± 0.0006. MinII
= 15m.27.
42. O'Connell effect. Primary minimum: HJD(TT) 2455439.317 ± 0.001. MinII
= 16m.51.
43. O'Connell effect. MinII = 16m.20.
44. A close pair of stars: 2MASS-18401586+0919466 and 2MASS 18401591+0919409;
2MASS 18401586+0919466 varies. Primary minimum: HJD(TT) 2455439.3408 ± 0.0008.
MinII
= 15m.70.
45. Maxima:HJD(TT) | ± |
2455439.3188 | 0.0008 |
2455450.2929 | 0.0006 |
46. MinII = 17m.28.
Remarks:
During observations of the field of variable star V651 Oph, we discovered 46 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 191 images with 5-minute exposures were obtained on JD 2455360–2455496.
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 0975-12485272 = USNO-B1.0 0995-0376789
(α=18h38m46s.81, δ=+09°34′ 38″.8,
J2000; 2MASS),
R1 = 14m.26, R2 = 13m.74
(USNO-B1.0). Unfiltered magnitudes were calibrated using the comparison star, assuming
Rcomp = 14m.00.
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.
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
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