Stars that have companions aren’t always friendly to them, as evidenced by a stellar confrontation witnessed by astronomers.
They studied the binary star system, HD101584, using the Atacama Large Millimeter/submillimeter Array of telescopes in Chile to find out what happened.
They discovered that the stars violently lashed out at each other. And it makes for a beautiful image.
The main star in the system inflated as it burned through its hydrogen stores and became a red giant, one of the last phases of stellar evolution before the star dies and becomes a white dwarf. Typical of red giants, the star swelled well beyond its original size, overtaking the other, lower-mass star.
But the small star lashed out in response, rather than withering away. It moved in a spiral motion toward the red giant’s core. Collision was averted, but the aggressive move was enough to cause the red giant to lose its outer layers of gas. Those layers scattered and the star’s core was exposed.
A study of the system was recently published in the journal Astronomy & Astrophysics.
“The star system HD101584 is special in the sense that this ‘death process’ was terminated prematurely and dramatically as a nearby low-mass companion star was engulfed by the giant,” said Hans Olofsson, lead study author at the Chalmers University of Technology in Sweden.
The end result of the stellar fight created a stunning nebula, comprised of ejected material and rings of gas layers in different colors.
Witnessing an event like this provides a better understanding for what our sun will go through as it evolves.
“Currently, we can describe the death processes common to many Sun-like stars, but we cannot explain why or exactly how they happen,” said Sofia Ramstedt, study co-author from Uppsala University in Sweden. “HD101584 gives us important clues to solve this puzzle since it is currently in a short transitional phase between better studied evolutionary stages. With detailed images of the environment of HD101584 we can make the connection between the giant star it was before, and the stellar remnant it will soon become.”
Future telescopes will enable astronomers to get a better look at the stars and determine more about them. For now, the star pair is too distant from us, and the stars are too close together, to learn more.