A space telescope observes a long-known star

A research team thinks they know the star well, and they're sorely mistaken. The James Webb Space Telescope reveals a big surprise.

WASHINGTON, D.C. – The star WL 20S is part of a young group of stars called WL 20 that has been closely studied by at least five telescopes since the 1970s. “After studying this source for decades, we thought we knew it pretty well,” says astronomer Marie Barsoni, lead author of a new study on WL 20S. The James Webb Space Telescope (JWST) was used in the investigation, and the research team was surprised by an unexpected discovery.

The star WL 20S is not just a single star, but an entire binary star system that formed about two to four million years ago, the JWST MIRI instrument shows. “Our jaws dropped,” Barsone recalls. NASA announcement. “If it wasn't for MIRI we wouldn't have known it was two stars. This is really amazing. It's like having completely new eyes.” The result was presented at the 244th meeting of the American Astronomical Society on June 12.

One of the stars in the system appears to be much younger than the others

“What we discovered was absolutely wild,” Barsone says in one of them. notice National Radio Astronomy Observatory. “We have known about the WL 20 star system for a long time. “But what we noticed was that one of the stars in this system appeared much younger than the others.”

Additional observations from the ALMA telescope in Chile confirmed the new discovery. “Using MIRI and ALMA, we saw that this star was actually two stars next to each other. “Each of these stars was surrounded by a disk, and each disk was emitting rays parallel to the other,” Barsoni explains. Disks of gas and dust around the stars could indicate that Planets form in these disks.

“The power of these two telescopes together is truly incredible.”

“The power of these two telescopes together is truly incredible,” confirms Mike Ressler, co-author of the study. “If we had not seen that there were two stars, the ALMA results would have looked like a single disk with a gap in the middle. Instead, we now have new data about two stars passing through At a critical stage in their lives.

The fact that the research team made this discovery was just a big coincidence, explains Ressler. He had some time left to observe the James Webb Space Telescope, and decided to observe WL 20 – a star system he had been studying for nearly 30 years. “We were very lucky with what we found and the results were amazing.”

WL 20S is located in the Rho Ophiuchi star-forming region

WL 20 is located in the well-studied Rho Ophiuchi star-forming region, about 400 light-years from Earth. The region is surrounded by dense clouds of gas and dust that block most visible light. However, the James Webb Space Telescope can detect infrared light penetrating these layers. MIRI detects the longest infrared wavelengths of all the instruments on board the telescope and is therefore particularly suitable for looking at obscure star-forming regions such as WL 20.