Comments:
3. Strong period changes. Two additional phased light curves for
narrow JD intervals are presented in the Figure (lc3.jpg).
5. Period changes.
7. Period changes.
8. MinII = 14.38.
10. An Algol-subtype eclipsing variable with narrow minima (D ~ 0.03).
The minima from plates of Moscow collection, ROTSE-I/NSVS database (Wozniak
et al. 2004),
and Catalina Sky Surveys were combined to determine the orbital period with higher
precision. The NSVS and Moscow photographic data shows presence of a secondary
minimum shifted from the phase 0.5 (orbital eccentricity). The phases of the
secondary minima are 0.454 and 0.464 (Moscow plates) and 0.453 (NSVS data).
Minima:
minima
| HJD |
Min |
Source |
| 2441804.515 |
I |
Moscow plate archive |
| 2441829.353 |
I |
Moscow plate archive |
| 2442364.184 |
II |
Moscow plate archive |
| 2442369.160 |
II |
Moscow plate archive |
| 2442869.471 |
I |
Moscow plate archive |
| 2445882.411 |
II |
Moscow plate archive |
| 2451286.721 |
II |
ROTSE-I/NSVS |
| 2451453.665 |
I |
ROTSE-I/NSVS |
| 2451463.659 |
I |
ROTSE-I/NSVS |
| 2454548.942 |
I |
Catalina Surveys |
13. Blazhko effect.
Remarks:
In the mid-1990s, I performed a search for new variable stars using plates
of the Moscow
collection in two fields centered at η Herculis and ξ Coronae Borealis (e.g.,
Antipin 1996a, Antipin 1996b). Some of the discovered variables could not be investigated
at that time. A recent inspection of this old list of discoveries shows that thirteen
objects still
remained
not announced as variable stars till present.
The new possibility of using the online
photometry of the Catalina
Surveys Data Release 1 (Drake et al. 2009) has allowed me to investigate the earlier
suspected stars, to derive their light
elements and variability types. A small number of bad data points that deviate strongly
from the
phased
light curves were rejected from the analysis.
Surprisingly, all RRC-type stars in the sample indicate noticeable periods changes,
while the RRAB-type stars show stable phased light curves.
The WinEfk software developed by Dr. V.P. Goranskij was used to search for periodicity.
The coordinates in the Table are from the 2MASS catalog (Skrutskie et al. 2006).
Acknowledgements: This study was supported, in part, by the Russian Foundation for
Basic Research through grant No. 11-02-00495. The CSS survey is funded by the National
Aeronautics
and Space Administration under Grant No. NNG05GF22G issued through the Science Mission
Directorate Near-Earth Objects Observations Program. The CRTS survey is supported
by
the U.S. National Science Foundation under grants AST-0909182.
References:
Antipin, S.V., 1996a, Inform. Bull. Var. Stars, No. 4343
Antipin, S.V., 1996b, Inform. Bull. Var. Stars, No. 4360
Drake, A.J., Djorgovski, S.G., Mahabal, A., et al., 2009, Astrophys. J., 696, 870
Skrutskie, M.F., Cutri, R.M., Stiening, R., et al., 2006, Astron. J., 131, 1163
Wozniak, P.R., Vestrand, W.T., Akerlof, C.W., et al., 2004, Astron. J., 127, 2436
