Chennai, Aug 3 (UNI) A team of astronomers from the Indian Institute of Astrophysics (IIA) made a ground-breaking discovery of a vampire star in M67, that sheds light on a complex rejuvenation process, known as mass-transfer in a binary system.
IIA is an autonomous institute of the Department of Science and Technology, Government of India, Astronomers at the IIA have long been chasing the formation path of vampire stars that are thought to rejuvenate their youth by sucking up material from their companion.
They have now discovered a vampire star that bears the chemical imprint of recently sucked barium-rich material from its binary companion and unambiguously detected emission from the dead-remnant of its companion.
The key to this detection was data from the UltraViolet Imaging Telescope, on board AstroSat, India’s first dedicated space observatory, ISRO said in a release.
This finding is an important missing link in the rejuvenation of these stars.
Vampire stars, known to astronomers as Blue Straggler Stars (BSS), are identified easily in star clusters. These stars defy simple models of stellar evolution and show many characteristics of younger stars.
This anomalous youth is explained theoretically as due to rejuvenation by eating up material from a binary stellar companion. Star clusters are useful test-beds to test this theory as they host a large number of binary stars, some of which can lead to the formation of vampire stars. Once rejuvenated, these stars follow a different path of evolution when compared to Sun-like single stars.
So far, the detection of sucked-up material along with the sighting of their remnant binary companion was elusive, it said.
Star clusters, being born from the same molecular cloud, can contain hundreds to thousands of stars with a wide range of masses but all contain very similar surface chemistry, making them ideal laboratories to understand how single and binary stars live and die.
One such intriguing star cluster is M67, located in the constellation Cancer. Recently, a team of astronomers from the IIA, made a ground-breaking discovery of a vampire star in M67, that sheds light on a complex rejuvenation process, known as mass-transfer in a binary system.
The research paper, to be published in The Astrophysical Journal Letters, provides rare insights into the binary star evolution process.
