Astronomers at the Atacama Observatory in Northern Chile have managed to capture data on the physical and chemical consequences of a “fight” between distant stars that will enable them to understand better what the Sun’s end will be like.
The scientists spotted a gas cloud in the star system known as “HD101584”, the result of this particular “star war” between two stars.
One star grew so large it engulfed the other which, in turn, spiraled towards its partner provoking it into shedding its outer layers.
Hans Olofsson from the Chalmers University of Technology in Sweden and director of the study that used the facilities of the ALMA Observatory (of which the European Southern Observatory, ESO, is a partner), explained that this star system has special characteristics.
Red giant engulfs a nearby star
“This ‘death process’ was terminated prematurely and dramatically as a nearby low-mass companion star was engulfed by the giant,” said Olofsson in an announcement from the ESO, in which he suggested that this was akin to “a stellar fight”.
The ESO reminded us that, “like humans, stars change with age and ultimately die. For the Sun and stars like it, this change will take it through a phase where, having burned all the hydrogen in its core, it swells up into a large and bright red-giant star.”
“Eventually, the dying Sun will lose its outer layers, leaving behind its core: a hot and dense star called a white dwarf,” added the observatory.
The scientists have been able to use the Atacama facilities to understand what happened. As the main star puffed up into a red giant, it grew large enough to swallow its lower-mass partner. In response, the smaller star spiraled in towards the giant’s core but didn’t collide with it.
This maneuver triggered the larger star into an outburst, leaving its gas layers dramatically scattered and its core exposed.
The team says the complex structure of the gas in the HD101584 nebula is due to the smaller star’s spiraling towards the red giant, as well as to the jets of gas that formed in this process.
Gigantic bluish and reddish blobs
As a “deadly blow” to the already defeated gas layers, these jets blasted through the previously ejected material, forming the rings of gas and the gigantic bluish and reddish blobs seen by the observatory.
The ESO explains that, “a silver lining of a stellar fight is that it helps astronomers to better understand the final evolution of stars like the Sun.” It also says that, “currently, we can describe the death processes common to many Sun-like stars, but we cannot explain why or exactly how they happen.”
Co-author Sofia Ramstedt from Uppsala University, Sweden, says that, “HD101584 gives us important clues to solve this puzzle since it is currently in a short transitional phase between better studied evolutionary stages.”
She adds that, “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.”
The contribution of the Chilean observatory has been crucial to this, but the astronomers are already imagining what they will be able to observe when the ELT (Extremely Large Telescope) is completed.
“It will provide information on the ‘heart’ of the object,” says Olofsson, who says the new telescope will allow astronomers “a closer look” at this particular “star war”.