Researchers find 155 new massive pulsating stars or candidates

Researchers led by Dr. Shi Xiangdong and Prof. Qian Shengbang from Yunnan Observatories of the Chinese Academy of Sciences (CAS) have detected a total of 155 massive pulsating stars or candidates based on TESS, LAMOST and Gaia data.

The study was published in The Astrophysical Journal Supplement Series on March 15.

Massive stars generally refer to O- and B-type stars, which have the characteristics of high mass, temperature and luminosity. They are related to many important objects and physical processes, such as neutron stars, black holes, supernovae and gravitational-wave events.

Massive pulsating stars are particular objects and their internal structure information can be obtained from asteroseismology. Slowly pulsating B (SPB) stars and β Cephei pulsating (BCEP) stars are the only two recognized classes of massive pulsating stars in the upper main sequence. However, limited by observational conditions, only hundreds of such objects have been detected so far.

In this study, the researchers found 155 OB-type pulsating stars or candidates, including 38 Oe/Be stars, from the data observed by TESS, LAMOST and Gaia, which are almost new. Among the 155 objects, 87 samples were identified as SPB stars, 14 samples as BCEP stars, 52 samples as candidates of them, and two samples as particular objects with the property of both SPB and BCEP stars.

The discovery of these targets is very important for understanding the theories of evolution and structure for massive pulsating stars, and reveals the potential for massive pulsating stars to be used as a standard candle to measure distances.

The study also derives the preliminary results of period-luminosity (P-L) relation for SPB and BCEP stars, respectively, and indicates that in addition to the H-R diagram, period-temperature (P-T) and P-L diagrams are also very useful for the classification of SPB and BCEP stars.