This is the first of a series of four papers, the goal of which is to identify the overcontact
eclipsing binary star systems for which a solid case can be made for mass exchange. To …

We performed photometric and spectroscopic studies on four W Ursae Majoris eclipsing
binaries (V384 Ser, AQ Psc, V480 Gem and 2MASS J07095549+ 3643564). The binaries …

We present multi-colour time-series CCD photometry of the solar-age galactic open cluster
M 67 (NGC 2682). About 3600 frames spread over 28 nights were obtained with the 1.5 m …

The first photometric, spectroscopic and period variation studies of neglected short-period
eclipsing binary V2840 Cygni are presented. High mass ratio contact binaries (HMRCBs) …

Based on O− C curves, we present detailed period investigations of two weak-contact
binaries CC Com and BV Dra. It is found that the periods of these two binaries have varied in …

In this paper, we present new BVRI light curves of short-period contact eclipsing binaries
V1101 Her and AD Phe from our observations carried out from 2014 to 2015 using the …

Aims. We report identification of cyclical changes in the orbital period of the eclipsing
cataclysmic variable HT Cas. Methods. We measured new white-dwarf mid-eclipse timings …

New CCD four-color light curves of TY Boo made on eight nights over 2010–2011 were
analyzed in comparison with historical light curves obtained from 1969 through 2011. The …

Photometric observations were conducted on the short-period and highly active M dwarf BX
Tri from 2016 to 2023. From ground-based observations and data from the Transiting …

New CCD photometric light curves of the short-period (P= 0.285 d) eclipsing binary RW Dor
are presented. The observations were performed with the PROMPT-8 robotic telescope at …