Received: 13.03.2012; accepted: 27.03.2012
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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).
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.
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.
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