A failed star calls astronomers “Accident.”

It was Dan Caselden created late on November 3, 2018, playing the video game Anti-Strike, when he made a history of astronomy. Each time he died, he jumped on his laptop to verify his automatic search with images from NASA’s space telescope.

Suddenly, in the early hours of the morning, something strange appeared. “It was very confusing,” Caselden said. “It was moving faster than I found it. He was humble and quick, which made him very weird. “

Caselden emailed the collaborating astronomers Backyard Worlds: 9. planet project. When they ruled out the possibility of having an image artifact, they realized they were seeing something completely unusual, a huge object 50 light-years away, traversing the galaxy at 200 kilometers per second. He was named WISE 1534-1043, but due to his special traits and accidental discovery, he was soon nicknamed “accident“.

Astronomers believe Caselden has discovered a brown dwarf, a failed star, with no part needed to start nuclear fusion at its base. “It looks like a star,” he said Sarah Casewell, Astronomer at the University of Leicester in the United Kingdom. “However, it never gets enough mass to get hydrogen into the helium and start burning anything.”

The discovery of the accident highlighted what we still need to learn about brown dwarfs. These objects have a mass of between 13 and 75 times or more of the estimated mass of Jupiter, but exactly where these two limits are is an ongoing dilemma. “People are constantly discussing it in congresses,” he said Beth Biller, An astronomer at the University of Edinburgh in the UK, mainly on the lower limit. 13 While the mass of Jupiter is approximately the mass deuterium fusion can occur—The characteristic that distinguishes brown dwarfs from giant gas planets — the limit can be changed. “The 13 masses on Jupiter have nothing special,” Biller said. “It’s completely ad hoc.”

Brown gnomes also vary greatly in temperature. The hottest temperatures are at surface temperatures around 2,000 degrees Celsius – “about a candle flame,” Biller said. The coldest are below 200 degrees. With no heat source of their own, brown dwarfs will gradually cool to lower temperatures over billions of years. (Sub-dwarfs, which blur the boundary between planets and brown dwarfs, may still be cooler. WISE 0855-0714 is below freezing. “It’s the coldest object we know outside of our solar system,” Biller said.)

It is also unclear what the brown dwarf might look like up close. Despite the name …Proposed by astronomer Jill Tarter In 1975, it was likely not to be brown. They are more orange or red. “It’s stuck as a name for good or bad,” he said Davy Kirkpatrick, Astronomer at the California Institute of Technology.

They also have atmospheres, and these atmospheres can show some kind of connection and occasional storms, just like Jupiter. Last year, Biller and his colleagues used these storms measure the wind speed of a brown dwarf About 34 light years away. First, they saw the characteristics of their atmosphere displayed and displayed while they were rotating, and then they compared this speed with the measurement of the speed of rotation inside the object received from its magnetic field. Comparing the two values, the researchers calculated a wind speed of 2,300 kilometers per hour — more than five times the wind of Jupiter.

Since brown dwarfs form a bridge between stars and planets, they can help both understand. At the upper end of the mass scale, the boundary between the largest brown dwarfs and the smallest stars may serve to determine how nuclear fusion begins. An object must reach high temperatures About 3 million degrees Celsius at its base to launch nuclear fusion, he said Nolan Grieves University of Geneva, Switzerland; this triggers a chain reaction that converts hydrogen into helium. But no one knows exactly how much mass is needed for this to happen, and at what point it becomes a brown dwarf star. “There are many aspects of our stellar evolution that are questionable,” Biller said. “One of those questions is where exactly that merger limit is.”