Pre-main sequence variable stars in young open cluster NGC 1893

TL;DR

This study identifies 53 variable stars in NGC 1893, characterizes their properties, and analyzes their variability, focusing on pre-main-sequence stars likely to be T Tauri stars, using multi-epoch photometry.

Contribution

It provides the first detailed photometric variability analysis of NGC 1893, identifying T Tauri candidates and their physical parameters.

Findings

53 variable stars identified in NGC 1893

Most pre-main-sequence stars are younger than 5 Myr and have masses between 0.5 and 4 solar masses

Classical T Tauri stars show larger brightness variations than Weak line T Tauri stars.

Abstract

We present results of multi-epoch (fourteen nights during 2007-2010) $V$-band photometry of the cluster NGC 1893 region to identify photometric variable stars in the cluster. The study identified a total of 53 stars showing photometric variability. The members associated with the region are identified on the basis of spectral energy distribution, $J-H/H-K$ two colour diagram and $V/V-I$ colour-magnitude diagram. The ages and masses of the majority of pre-main-sequence sources are found to be $\lesssim$ 5 Myr and in the range 0.5 $\lesssim$ $M/M_{\odot}$ $\lesssim$ 4, respectively. These pre-main-sequence sources hence could be T Tauri stars. We also determined the physical parameters like disk mass and accretion rate from the spectral energy distribution of these T Tauri stars. The periods of majority of the T Tauri stars range from 0.1 to 20 day. The brightness of Classical T Tauri stars is found to vary with larger amplitude in comparison to Weak line T Tauri stars. It is found that the amplitude decreases with increase in mass, which could be due to the dispersal of disks of massive stars.