CSS and SuperWASP Data for Five Variable Stars Discovered on Moscow Archive Plates

S. V. Antipin
Sternberg Astronomical Institute, Lomonosov Moscow State University, and Institute of Astronomy, Russian Academy of Sciences, Moscow, Russia

Received:   23.11.2012;   accepted:   14.12.2012
(E-mail for contact: antipin@sai.msu.ru)

Comments:


1. The star was found in outburst only on three Moscow archive plates taken with the 40-cm astrograph on March 8–9, 1973 (JD2441750.517, 2441750.552, 24750.579; B_pg ~ 14.1 on all three images). A small part of the first plate is reproduced in the right panel of the finding chart (fchart1.jpg). Later USNO-B1.0 1241-0240997 = SDSS J162212.45+341147.3 was suspected to be a cataclysmic variable star from Sloan spectra (Szkody et al. 2004). Strong hydrogen Balmer and helium emission lines are present in the spectra.
The star seems to vary in minimum brightness based on Catalina Sky Surveys photometry (see lc1.jpg). The tabulated magnitude in minimum is an average of two USNO-B1.0 blue magnitudes.

3. Min_II = 15.45.

4. Min_II = 16.00.

5. 1RXS J170956.8+425027. Rotating chromospheric active star with very fast changes of its phased light curve. Three seasons of WASP data (Butters et al. 2010) gave a possibility to detect the following changes of amplitude and light elements (the observations with errors exceeding 0^m.05 were rejected from the analysis):
Max = 2453923.4 + 1.947 x E (2453827–53950); Ampl ~ 0^m.10;
Max = 2454224.73 + 1.9436 x E (2454189–54316); Ampl ~ 0^m.16;
Max = 2454620.55 + 1.9430 x E (2454553–54681); Ampl ~ 0^m.27.
The elements in the Table are for the last season of SuperWASP data. No periodic variability was found in the Catalina Sky Survey data close to the period of 1.94 days because of the long interval of observations and the mentioned fast light-curve changes.
J = 10.034, H = 9.463, K = 9.334 (2MASS) for the bright component of the close pair, which is the variable star.

Remarks:
The new possibility of using the online publicly available photometry (Catalina Sky Surveys data, Drake et al. 2009, and WASP data, Butters et al. 2010) allowed me to investigate and classify five variable stars that earlier were suspected on Moscow archive plates.
A small number of bad data points that deviate strongly from the phased light curves were rejected from the analysis.
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 Catalina Sky Surveys are funded by the National Aeronautics and Space Administration under Grant No. NNG05GF22G issued through the Science Mission Directorate Near-Earth Objects Observations Program. The author is grateful to Dr. V.P. Goranskij for providing his lightcurve analysis software.

References:
Butters, O.W., West, R.G., Anderson, D.R., et al., 2010, Astron. and Astrophys., 520, L10
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
Szkody, P., Henden, A., Fraser, O., et al., 2004, Astron. J., 128, 1882