2018/02/06 by Somnath Dutta, Soumen Mondal, Santosh Joshi +4
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Photometry (optics) #Physics #Stars #Stellar, planetary, and galactic studies #Variable star #astro-ph.GA #astro-ph.SR
paper · pdf · doi:10.1093/mnras/sty329
openalex publication_date 2018/02/06 · arxiv created 2018/02/07 · arxiv updated 2018/04/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report here CCD I-band time series photometry of a young (2–5 Myr) cluster NGC 2282, in order to identify and understand the variability of pre-main-sequence (PMS) stars. The I-band photometry, down to ∼20.5 mag, enables us to probe the variability towards the lower mass end (∼0.1 M⊙) of PMS stars. From the light curves of 1627 stars, we identified 62 new photometric variable candidates. Their association with the region was established from H α emission and infrared (IR) excess. Among 62 variables, 30 young variables exhibit H α emission, near-IR (NIR)/mid-IR (MIR) excess or both and are candidate members of the cluster. Out of 62 variables, 41 are periodic variables, with a rotation rate ranging from 0.2–7 d. The period distribution exhibits a median period at ∼1 d, as in many young clusters (e.g. NGC 2264, ONC, etc.), but it follows a unimodal distribution, unlike others that have bimodality, with slow rotators peaking at ∼6–8 d. To investigate the rotation–disc and variability–disc connection, we derived the NIR excess from Δ(I − K) and the MIR excess from Spitzer [3.6]–[4.5] |μ|m data. No conclusive evidence of slow rotation with the presence of discs around stars and fast rotation for discless stars is obtained from our periodic variables. A clear increasing trend of the variability amplitude with IR excess is found for all variables.