Comments:
1. Maxima:HJD(TT) | ± |
2455769.437 | 0.003 |
2456047.424 | 0.005 |
2456049.468 | 0.003 |
2456189.2651 | 0.0008 |
2. A close pair of two stars: USNO-A2.0 0900-12932590 and 2MASS 18283560+0259315.
USNO-A2.0 0900-12932590 varies. Infrared colors J–H = 1.044, H–K = 0.344
and J–K = 1.388 (2MASS)
are consistent with the M spectral type (Bessell and Brett 1988) and SR: classification.
Maximum: HJD(TT) 2456186.7±0.5.
3. A close triplet of stars USNO-A2.0 0900-12933840, 2MASS 18283742+0318015, and
a faint star not contained in any catalogues. USNO-A2.0 0900-12933840 varies.
Maximum:
HJD(TT) 2456200.2274±0.0009.
4. Primary minima:HJD(TT) | ± |
2455344.3523 | 0.0007 |
2456173.2661 | 0.0008 |
2456183.2770 | 0.0004 |
2456200.2275 | 0.0009 |
MinII = 16m.26.
5. Infrared colors J–H = 0.973, H–K = 0.340 and J–K = 1.313 (2MASS)
are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
6. Infrared source IRAS 18264+0329. Infrared colors J–H = 1.102, H–K
= 0.400 and J–K = 1.502
(2MASS) are consistent with the M spectral type (Bessell and Brett 1988) and LB classification.
7. Infrared colors J–H = 1.002, H–K = 0.345 and J–K = 1.347
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
Maxima:HJD(TT) | ± |
2455747.0 |
0.9 |
2456199.5 | 0.6 |
9. Period 0d.9810 is also possible.
10. Infrared colors J–H = 1.026, H–K = 0.503 and J–K = 1.529
(2MASS)
are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
Maxima:HJD(TT) | ± |
2455803 | 1 |
2456208 | 1 |
11. A close pair of two stars: USNO-A2.0 0900-12961808 and a faint star, not contained
in any catalogues. USNO-A2.0 0900-12961808 varies. Infrared colors J–H = 1.036,
H–K = 0.374 and
J–K = 1.410 (2MASS) are consistent with the M spectral type (Bessell and Brett
1988)
and SR: classification.
12. Primary minima:HJD(TT) | ± |
2455344.3580 | 0.0004 |
2455772.4432 | 0.0007 |
2455785.3063 | 0.0002 |
2455815.3373 | 0.0008 |
2456049.4515 | 0.0010 |
2456052.511 | 0.001 |
2456173.2469 | 0.0002 |
MinII = 13m.95.
13. Infrared colors J–H = 1.021, H–K = 0.333 and J–K = 1.354
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
Maximum: HJD(TT) 2455773±1.
14. Infrared colors J–H = 1.079, H–K = 0.488 and J–K = 1.567
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and LB classification.
15. Infrared colors J–H = 1.071, H–K = 0.431 and J–K = 1.502
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
Maximum: HJD(TT) 2455778.0±1.5.
16. Infrared colors J–H = 1.094, H–K = 0.383 and J–K = 1.477
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
17. Infrared colors J–H = 0.848, H–K = 0.305 and J–K = 1.153
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
Maximum: HJD(TT) 2456203±2.
18. Infrared colors J–H = 1.043, H–K = 0.501 and J–K = 1.544
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
Maximum: HJD(TT) 2455757±1.
19. Infrared colors J–H = 0.933, H–K = 0.337 and J–K = 1.270
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
Maxima:
20. Maxima:HJD(TT) | ± |
2455772.4814 | 0.0008 |
2455784.3359 | 0.0009 |
2456183.258 | 0.002 |
2456218.2414 | 0.0005 |
21. A close pair of two stars: USNO-A2.0 0900-13004335 and a faint star, not contained
in any catalogues. USNO-A2.0 0900-13004335 varies. Infrared colors J–H = 1.000,
H–K = 0.385 and
J–K = 1.385 (2MASS) are consistent with the M spectral type (Bessell and Brett
1988)
and SR: classification.
22. Infrared colors J–H = 1.066, H–K = 0.281 and J–K = 1.347
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
23. Infrared colors J–H = 1.037, H–K = 0.440 and J–K = 1.477
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
Maxima:HJD(TT) | ± |
2455734.6 | 0.5 |
2456180.8 | 0.7 |
24. A close pair of two stars: USNO-A2.0 0900-13012157 and a faint star, not contained
in any catalogues. USNO-A2.0 0900-13012157 varies. Infrared colors J–H = 1.080,
H–K = 0.296
and J–K = 1.376 (2MASS) are consistent with the M spectral type (Bessell and
Brett 1988)
and SR: classification.
25. Infrared colors J–H = 1.131, H–K = 0.455 and J–K = 1.586
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and LB classification.
26. A close triplet of stars USNO-A2.0 0900-13019383 and two faint stars, not contained
in any catalogues. USNO-A2.0 0900-13019383 varies. Infrared colors J–H = 1.101,
H–K = 0.429
and J–K = 1.530 (2MASS) are consistent with the M spectral type (Bessell and
Brett 1988)
and SR: classification.
Maxima:
27. A close triplet of stars USNO-A2.0 0900-13022138, NOMAD1 0935-0383912 and NOMAD1
0935-0383907. USNO-A2.0 0900-13022138 varies. Infrared colors J–H = 1.160,
H–K = 0.462
and J–K = 1.622
(2MASS) are consistent with the M spectral type (Bessell and Brett 1988) and SR:
classification.
28. Infrared colors J–H = 1.103, H–K = 0.382 and J–K = 1.485
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
29. Blazhko effect with a period of 53d.4.
Maxima:HJD(TT) | ± |
2455344.4166 | 0.0006 |
2455432.366 | 0.001 |
2456173.3065 | 0.0004 |
2456195.2942 | 0.0008 |
30. USNO-A2.0-0900-13034971 is located near the position of a known variable star,
NSVS
13891310,
discovered
by Benko and Csubry (2007) using NSVS data. The angular resolution of the ROTSE-I
instrument
is insufficient for a decision which star varies. Using our telescope, we confidently
identified the variable star and determined its variability parameters. Infrared
colors J–H
= 1.059,
H–K = 0.524 and
J–K = 1.583 (2MASS) are consistent with the M spectral type (Bessell and Brett
1988)
and Mira classification.
31. Infrared colors J–H = 0.772, H–K = 0.295 and J–K = 1.067
(2MASS) are consistent with the
K-M spectral type (Bessell and Brett 1988) and BY: classification.
32. Infrared colors J–H = 0.778, H–K = 0.245 and J–K = 1.023
(2MASS) are consistent with the
K-M spectral type (Bessell and Brett 1988) and SR: classification.
Maxima:HJD(TT) | ± |
2455733.9 | 0.7 |
2455781.6 | 0.7 |
2456193.4 | 0.3 |
33. Infrared colors J–H = 1.122, H–K = 0.482 and J–K = 1.604
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
Maxima:HJD(TT) | ± |
2455747.9 |
0.8 |
2456178.9 | 0.6 |
34. Infrared colors J–H = 1.105, H–K = 0.459 and J–K = 1.564
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
35. Infrared colors J–H = 1.125, H–K = 0.424 and J–K = 1.549
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
36. Primary minima:HJD(TT) | ± |
2456174.3115 | 0.0006 |
2456195.2510 | 0.0006 |
MinII = 14m.48.
37. Infrared colors J–H = 1.202, H–K = 0.438 and J–K = 1.640
(2MASS) are consistent with the
M spectral type (Bessell and Brett 1988) and SR: classification.
Remarks:
During observations of a field at the borderline of Ophiuchus and Serpens, we
discovered
37 new
variable stars. Our observations were carried out at the Astrotel-Caucasus observatory,
located at
the Astronomical station of the Kazan Federal university, using the 300-mm
Ritchey-Chretien telescope, equipped with an unfiltered Apogee Alta U9000 CCD camera.
A total of 1327 images with 5-minute exposures were obtained on JD 2455018–2456218.
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 0900-13006962 = USNO-B1.0 0936-0378151,
α = 18h30m09s.78, δ = +03°36′
55″.1
(J2000, 2MASS),
R1 = 13m.73, R2 = 13m.72
(USNO-B1.0). Unfiltered magnitudes were calibrated using the comparison star, assuming
Rcomp = 13m.725.
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:
Benko, J.M., Csubry, Z., 2007, Acta Astron., 57, 73
Bessell, M.S., Brett, J.M., 1988, Publ. Astron. Soc. Pacific, 100, 1134
Skrutskie, M.F., Cutri, R.M., Stiening, R., et al., 2006, Astron. J., 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