NGC 7419 membership and variability

CBe stars are main-sequence non-supergiant B-type stars that exhibit or have exhibited Balmer-line emissions in their spectra. We perform a membership analysis using Gaia DR3 data and machine learning techniques like Gaussian mixture models and Random Forest and determine the cluster's mean distance to be 3.6^+1.0^_-0.6_kpc.

We identify 499 Gaia-based members with a mass above ~1.2M_{sun}_, and estimate the cluster's age to be 21.1^+1.6^_-0.6_Myr. Using our revised Halpha excess-based analysis, we find 42 CBe stars containing many known CBe stars, bringing the total number of CBe stars in NGC 7419 to 49 and the fraction of CBe to (B + CBe) members to 12.7 per cent. We investigate the variability of the candidate members from Zwicky Transient Facility and NEOWISE data using standard deviation, median absolute deviation, and Stetson index (J), and their periodicity using the Generalized Lomb-Scargle periodogram variability.