Photometric Search for variable stars in the field of two Northern open clusters, DOLIDGE 14 and NGC 1960

TL;DR

This study identifies and analyzes variable stars in the fields of two open clusters, NGC 1960 and DOLIDGE 14, using photometric methods to classify their types and assess their membership and evolutionary status.

Contribution

The paper presents new variable star discoveries in two open clusters and applies comprehensive photometric calibration and analysis methods to classify and evaluate their properties.

Findings

18 variable stars in NGC 1960, including 14 new discoveries

4 variable stars in DOLIDGE 14, with different types identified

Membership analysis suggests some stars are cluster members and others are not

Abstract

The aim of present work is extract and analyses the light curves of the stars in the field of two clusters, NGC 1960 and DOLIDZE 14. The photometric calibration is performed by comprehensive method of secondary standard transformation and differential photometry using two comparison stars per candidate variable star. The resultant light curves for each potential variable star are displayed and their period analyzed by two different methods. The period and classification of 18 discovered short periodic type variable stars of NGC 1960 are discussed, which consist of four known variable stars and fourteen new variable stars. In the case of DOLIDZE 14, four discovered variables consist of one miscellaneous, one rotational, two $binary$ type variable stars. In the case of NGC~1960, the 12 selected comparison stars appear to be likely candidate for long periodic variability and 4 stars may be standard stars. The variation in brightness of other twenty comparison stars is non-pulsating with an irregular pattern. Membership analysis of variable stars is performed using their distance, kinematic probability and location in $(U-B)$ vs $(B-V)$ TCD. C-M diagrams were constructed to confirm the evolutionary state of the new variable stars.