X-Ray Research Reveals New Particulars About Betelgeuse’s Elusive Companion Star – Information

Astronomers have lengthy suspected that Betelgeuse — the brilliant crimson star blazing in Orion’s shoulder — wasn’t alone. Now, due to a fleeting cosmic window and swift motion by Carnegie Mellon University researchers, the true nature of its elusive companion has been illuminated.

In a race towards time, the CMU researchers secured director’s discretionary time on each NASA’s Chandra X-ray Observatory and the Hubble Space Telescope to research the long-predicted — however by no means detected — companion star to Betelgeuse. The timing was essential: Around Dec. 6, the companion, nicknamed “Betelbuddy,” reached its most separation from the large crimson supergiant simply earlier than it will disappear behind it for 2 extra years.

“It turns out that there had never been a good observation where Betelbuddy wasn’t behind Betelgeuse,” stated Anna O’Grady, a McWilliams Postdoctoral Fellow at Carnegie Mellon’s McWilliams Center for Cosmology and Astrophysics(opens in new window). “This represents the deepest X-ray observations of Betelgeuse to date.”

During this ideally suited observational window, the Gemini North Telescope in Hawaii captured a faint picture close to Betelgeuse that might be its tiny companion. In a separate examine, the Carnegie Mellon-led workforce used Chandra to gather X-ray knowledge to find out the character of the mysterious object.

“It could have been a white dwarf. It could have been a neutron star. And those are very, very different objects,” O’Grady stated. “If it was one of those objects, it would point to a very different evolutionary history for the system.”

But it wasn’t both. O’Grady and her collaborators discovered no proof of accretion — a trademark of compact objects like neutron stars or white dwarfs. Their findings, to be revealed in The Astrophysical Journal(opens in new window), level as an alternative to a younger stellar object roughly the dimensions of the solar. A companion paper from researchers on the Flatiron Institute, utilizing Hubble knowledge, helped slender down the companion’s dimension.

Telescopes reserve a small portion of their allotted time for time-critical, distinctive or high-priority analysis proposals. To have two proposals accepted to view the identical occasion is reserved for essentially the most thrilling potential outcomes.

The thought to suggest for observing time got here up throughout a weekly McWilliams Center journal membership. “At first it seemed like an extreme longshot, but the more we talked, the more we realized our team had a unique combination of expertise to possibly succeed in getting director’s time. It was awesome to see a casual conversation turn into a super exciting discovery opportunity,” stated Katelyn Breivik,(opens in new window) the Falco DeBenedetti Career Development Professor in Physics.(opens in new window)

Astronomers have lengthy speculated that Betelgeuse may need a companion, however its sheer brightness — about 700 occasions the dimensions of our solar and hundreds of occasions brighter — makes detecting close by objects extraordinarily troublesome.

“The brightness difference between Betelgeuse and this little companion is absolutely insane,” O’Grady stated. “The fact that we can now confirm something is there shows how far our science has come.”

The discovery additionally sheds gentle on Betelgeuse’s puzzling six-year cycle of brightening and dimming. A 2024 examine by O’Grady’s co-author Jared Goldberg, a analysis fellow on the Flatiron Institute, proposed that an orbiting companion star clears away light-blocking mud, permitting Betelgeuse to seem brighter from Earth. But nobody knew for positive whether or not the companion truly existed. So, like a health care provider who would possibly order extra checks to substantiate a analysis, O’Grady, Goldberg and collaborators ordered a couple of imaging checks to take a extra thorough look.

“We ordered two that we thought would be good and that our team had relevant expertise in — UV spectroscopy and X-ray imaging,” O’Grady stated.

The implications stretch past Betelgeuse. Binary star pairs are usually thought to have related lots, however Betelgeuse is estimated to be 16 or 17 occasions the mass of the solar, whereas its companion is only one photo voltaic mass or much less — a staggering ratio that challenges standard fashions.

“This opens up a new regime of extreme mass ratio binaries,” O’Grady stated. “It’s an area that hasn’t been explored much because it’s so difficult to find them or to even identify them like we were able to do with Betelgeuse.”

In addition to O’Grady and Breivik, Carnegie Mellon’s Brendan O’Connor, a McWilliams Postdoctoral Fellow, additionally contributed to the analysis.