Observational and Theoretical Studies of 27 $\delta$ Scuti Stars with Investigation of the Period-Luminosity Relation

TL;DR

This study combines observational data, Gaia parallaxes, and machine learning to analyze 27 Delta Scuti stars, deriving their physical parameters and refining the period-luminosity relation for different pulsation modes.

Contribution

It introduces new P-L relations for Delta Scuti stars using a machine learning approach and provides detailed physical parameters for a sample of 27 stars.

Findings

New period-luminosity relations for fundamental and overtone modes.

Physical parameters like masses and radii estimated for all stars.

Machine learning classification improved P-L relation accuracy.

Abstract

The multi-color CCD photometric study of 27 Delta Scuti stars is presented. By using approximately three years of photometric observations, we obtained the times of maxima and magnitude changes during the observation time interval for each star. The ephemerides of our Delta Scuti stars were calculated based on the Markov Chain Monte Carlo (MCMC) method using the observed times of maxima and the period of the stars' oscillations. We used the Gaia EDR3 parallaxes to calculate the luminosities and also the absolute magnitudes of these Delta Scuti stars. The fundamental physical parameters of all the stars in our sample such as masses and radii were estimated. We determined the pulsation modes of the stars based on the pulsation constants. Moreover, the period-luminosity (P-L) relation of Delta Scuti stars was investigated and discussed. Then, by using a machine learning classification, new P-L relations for fundamental and overtone modes are presented.