The ‘bare, pulsating core of a massive star’ observed for the first time
A trio of researchers from the Friedrich-Alexander University Erlangen-Nuremberg, the Universität Innsbruck and the University of Geneva have discovered the “bare, pulsating core of a massive star” for the first time. In his paper published in the journal Natural astronomyAndreas Irrgang, Norbert Przybilla and Georges Meynet describe the unique object and the work they did to verify its composition.
Stellar cores, as their name suggests, are the innermost parts of stars. Most often, such cores are covered by what space scientists call their “opaque mantle.” The theory suggested that such cores could appear without an envelope if conditions arose that lead to its removal. But until now it has never been noticed.
In their paper, the researchers write that their discovery of what was believed to be an average, normal star, called γ Columbae, was purely “accidental”. They looked at a group of stars and found that their data suggested that one of them was unusual. This led them to take a closer look at the spectrum of light emitted by the star, and in the process, discover evidence of a missing envelope.
For such an object to exist, the researchers note, something had to strip the mantle from a normal star, leaving behind its core. That would leave the facility significantly smaller. They estimate that the star γ Columbae was probably about 12 times the mass of the Sun before it lost its envelope – it is now only five times the mass of the Sun.
The researchers also note that the sighting of the unique object was indeed a matter of chance – they point out that such an object would not remain as a bare core for long – perhaps only 10,000 years or so, which is a blink of an eye in astronomical terms. They also note that previous research suggests that before it was stripped, γ Columbae was probably an ordinary massive star that probably ran out of hydrogen.
This would force her envelope to expand, possibly pulling in a companion of the stars, which could have caused the envelope to be ejected. They note that currently the object is burning helium, but at some point it will begin to fuse heavier elements until it explodes as a core-bare supernova, and then it will become a neutron star.
Andreas Irrgang et al, γ Columbae as a recently stripped pulsating core of a massive star, Natural astronomy (2022). DOI: 10.1038/s41550-022-01809-6
© 2022 Science X Network
Citation: ‘Bared, Pulsating Core of Massive Star’ Spotted for First Time (2022 November 1) Retrieved November 2, 2022 from https://phys.org/news/2022-11-pulsating-core-massive-star.html
This document is subject to copyright. Except for any fair dealing for the purpose of private study or research, no part may be reproduced without written permission. The content is provided for informational purposes only.
#bare #pulsating #core #massive #star #observed #time