Thanks to research from The Australian National University (ANU) and China’s Yunnan Observatory, we now have new clues about a mysterious stage in the lives of binary stars.
Half of all stars exist in pairs, which are known as binary stars. We understand the lives of single stars, but the lives of star couples are more complicated.
According to the study’s co-author, Associate Professor Christian Wolf of ANU, the “common envelope phase” is especially important for binary stars, but it had never been observed before.
The research team discovered a tight binary star with an expanding shell of material around it for the first time—the remnant of the common envelope.
“In the early stages, two stars frequently circle each other with nothing happening,” Associate Professor Wolf explained.
“However, when one of the stars becomes a red giant, it does not simply claim more empty space as a single star does.”
Instead, its ’embraces’ or engulfs its companion, and the two appear as a single star hidden behind an opaque envelope. That’s when things start to heat up. The friction of their movement inside the envelope has a significant impact on what happens next for the stars. It not only causes heat but also slows the stars, causing them to spiral into ever-tighter orbits; the envelope eventually overheats and blows away.”
This particular binary star exploded around 10,000 years ago.
“The common envelope phase is a missing link in the extremely long and complex chain of events that comprise a star’s life. We are now working to repair that link “Wolf, Associate Professor, stated.
“It may even aid in the reconstruction of gravitational wave events such as black hole mergers.”
According to the researchers, this first glimpse of the phenomenon could lead to the discovery of more stars at this critical stage of their lives.
“It might be easier to spot them now that we know what to look for. Others may have been right under our noses the whole time “Wolf, Associate Professor, stated
The findings were published in the Royal Astronomical Society’s Monthly Notices.