RAT J0455+1305: A rare hybrid pulsating subdwarf B star

TL;DR

This paper reports on the discovery and analysis of RAT J0455+1305, a rare hybrid pulsating subdwarf B star exhibiting both pressure and gravity modes, providing valuable data for stellar modeling.

Contribution

It presents detailed photometric analysis of a rare hybrid sdB star, identifying multiple pulsation frequencies and modes, and compares it to similar known stars to aid theoretical understanding.

Findings

Six short-period frequencies identified, including a combination mode.

Six long-period frequencies identified.

Star exhibits mode groupings similar to other hybrid sdB stars.

Abstract

We present results on the second-faintest pulsating subdwarf B (sdB) star known, RAT J0455+1305, derived from photometric data obtained in 2009. It shows both short and long periods oscillations, theoretically assigned as pressure and gravity modes. We identify six short-period frequencies (with one being a combination) and six long-period frequencies. This star is the fourth hybrid sdB star discovered so far which makes it of special interest as each type of mode probes a different part of the star. This star is similar to the sdB hybrid pulsator Balloon 090100001 in that it exhibits short-period mode groupings, which can be used to identify pulsation parameters and constrain theoretical models.