Study of the variable star ASASSN-V j104912.47+274312.7; a rare peculiar RRc star

TL;DR

This study refines the period of a peculiar RRc variable star, revealing it belongs to a rare subgroup with two close frequencies and unusual period ratios, similar to other known stars.

Contribution

It identifies and characterizes a rare subgroup of RRc stars with two close frequencies and high period ratios, expanding understanding of stellar pulsation modes.

Findings

Refined the star's period through 16 nights of observations.

Discovered the star's belonging to a rare subgroup with two close frequencies.

Identified similarities with other peculiar RRc stars in literature.

Abstract

During a screening in ASAS-SN database searching candidates of Delta Scuti stars with short period, our attention was drawn to the variable star ASASSN-V J104912.47+274312.7, we considered interesting to follow. It is an ASAS-SN discovery, classified by them as a RRc. We observed it for 16 nights in 2021, obtaining several maxima that allow us to refine its period. After a frequency analysis, we conclude that this star belongs to a small subgroup of RRc stars having the peculiarity to show two close frequencies with ratio greater than 0.96, without 0.61 or 0.68 period ratio mode. This behaviour is very similar to two stars found by Netzel & Smolec (2019) in OGLE data, and one star in NGC 6362, studied by Smolec et al. (2017). This large period ratios are also found as additional mode to standard double mode RRc stars (Px/Pl= 0.61-0.68) by Netzel et al. (2023).