GSC 02626-00896: an RR Lyrae star with a ceasing Blazhko effect and three new variables in the field

TL;DR

This study reanalyzed data of the RR Lyrae star GSC 02626-00896, revealing the cessation of its Blazhko effect, and discovered three new eclipsing variables in its field, providing updated ephemerides and light curve characteristics.

Contribution

It provides the first detailed analysis showing the Blazhko effect has ceased in GSC 02626-00896 and reports three newly identified variable stars in the same field.

Findings

GSC 02626-00896 no longer shows Blazhko modulation.

Three new eclipsing variables were identified in the field.

Updated ephemerides and light curve data for all variables.

Abstract

By analysis of Superwasp data, Srdoc and Bernhard (2012) have shown recently that GSC 02626-00896 (18:09:30.34 + 32:45:13.52) is an RRc type variable showing indications of Blazhko effect. A night by night reanalysis of the data shows that in fact a 26 d secondary period is present in the 2004 observations. However, no trace of this can be found in the 2007 and 2008 data. CCD observations of the star on 19 nights in 2012 yielded a strictly repeating light curve with a broad maximum similar to those derived from the second and third SWASP data group. A slightly revised ephemeris Max.(HJD) = 2456069.3919(43) + 0.32272138(60) d x E could be derived. The CCD observations also revealed three short period eclipsing variables in the field of GSC 02626-00896. The 15.16 R mag. GSC2.3 star N25F001920 (18:09:24.282 +32:44:51.72) shows 0.15 and 0.1 mag. shallow eclipses with the ephemeris Max.(HJD) = 2456064.5155(13) + 0.389228(18) d x E. The 15.39 R mag. GSC 2.3 N25D013720 (18:09:41.141 +32:33:46.99) is a W UMa type star with the ephemeris Min.(HJD) = 2456072.4354(4) + 0.393563(7) d x E and 0.45 mag. amplitude. The 16.13 R mag. GSC 2.3 N25D015132 (18:09:01.767 +32:36:53.59) is also a W UMa type star with the ephemeris Min.(HJD) = 2456072.4909(2) + 0.287800(3) d x E with an amplitude of 0.75 and 0.5 mag respectively.