[ad_1]
Scientists finally solved the mystery surrounding a brilliant blue ring of light that was unlike anything astronomers had seen before.
Astronomers spent years trying to understand why the mysterious object in space had a circle of blue light around it, analyzing images taken with telescopes both on the ground and in space.
Scientists now believe they have figured out how blue light formed, ending the 16-year mystery and describing the story of a spectacular and dramatic object in distant space.
Astronomers argue that the blue ring is not a ring at all, but a cone. The cloud of fluorescent debris probably formed after a sun-like star swallowed a smaller companion, and since one of the cones faces directly towards Earth, it looks like a ring from here.
(The ring isn’t strictly blue either, but color is instead a way to represent the otherwise invisible light surrounding the object.)
The observation is the first time that astronomers have witnessed a rare phase in the evolution of stars that occurs only a few thousand years after the start, and lasts only perhaps thousands of years, a short period on the scale of the stars.
The two stars began life floating in space, but as the sun-like star expanded and approached the other star, the smaller of the two began pouring material from its older brother.
Eventually, as the smaller star consumed itself, the collision launched a cloud of debris that was split in two by a gas disk from the smaller star, thus creating the two cone-shaped debris clouds.
The hydrogen molecules in the debris were then excited by the shock wave, causing them to glow with ultraviolet light, giving the cloud its titular hue.
“The merger of two stars is quite common, but they are quickly obscured by a lot of dust as the ejection from them expands and cools into space, which means we can’t see what really happened,” says the lead author of the study Keri Hoadley, the David and Ellen Lee Postdoctoral Scholar in Physics at Caltech.
“We think this object represents an advanced stage of these transient events, when the dust finally clears and we have a good view,” says Hoadley. “But we also detected the process before it was too long; after time, the nebula will dissolve into the interstellar medium and we wouldn’t be able to tell that anything happened.”
The mystery has baffled scientists for years since it was discovered. “Whenever we thought we understood this, something would tell us ‘No, that’s not right,'” said Mark Seibert, an astrophysicist with the Carnegie Institution for Science and a member of the GALEX team.
“It’s a scary thing as a scientist. But I also like how unique this object is and the effort so many people put in to understand it.”
While trying to figure out what caused the star, scientists came up with numerous ideas. Using Caltech’s Hale telescope at Palomar Observatory, near San Diego, and WM Keck Observatory in Hawaii, they tried to find evidence of a shock wave around the star that would suggest a gas cloud was sent into space. .
Later, it was speculated that the star could destroy an invisible planet nearby, but data from the Habitable Zone Planet Finder which was released in 2017 showed that there was no such object orbiting the star.
While it took a surprisingly long time to uncover the cause of the blue rings, the use of new technology means that old programs are still revealing new information.
“Whenever you look at the sky at new wavelengths, you inevitably get new discoveries years later and beyond,” said Christopher Martin, a physics professor at Caltech and former principal investigator at GALEX.
Source link
