Dr. CHEN Xinghao from Yunnan Observatories of the Chinese Academy of Sciences (CAS) and his cooperators conducted a systematic search for δ Scuti-type pulsations in the 6,431 eclipsing binaries with orbital periods shorter than 13 days.

They found a total of 242 pulsators in these systems, including 123 newly discovered δ Scuti-type pulsating stars, which increases the total number of eclipsing binaries with δ Scuti-type pulsations by about 35%.

This study was published in The Astrophysical Journal Supplement Series on Dec. 5.

Eclipsing binaries with pulsating components are becoming popular in recent decades in understanding the theory of stellar structure and evolution. The binarity provides us with accurate ways to measure physical parameters of the system, and the oscillations offer us significant insight into the physics behind the pulsation nature of stars.

Pulsating stars include δ Scuti-type, γ Doradus-type, pulsating red giants, etc. Due to the relatively short periods and large amplitudes, the δ Scuti-type pulsating stars in eclipsing binaries are much more than other types of pulsators. Up to now, about 350 δ Scuti-type pulsators have been identified in eclipsing binaries.

Based on 6,431 eclipsing binaries observed by TESS in the 2-minute cadence photometric data from sectors 1-50, after eliminating the light changes due to eclipses and removing the orbital-harmonic peaks, the researchers found 242 binaries showing pulsations, of which 143 objects were newly discovered.

They examined their pulsation properties and the relationships between the dominant pulsation period, orbital period and effective temperature. As a result, 216 targets were identified to be likely δ Scuti-type pulsating stars, including 123 new discoveries.

The study provides a vast sample of eclipsing binaries with pulsating components, which will improve our knowledge of stellar structure and evolution as well as the characteristics of pulsation in eclipsing binaries.