The Bételgeuse star has a “friend” who sticks to her orbit, a major observation – RTS.CH

“A boyfriend (buddyin English) for Bételgeuse “. Furthermore, titled last December a study Astronomers published in The Astrophysical Journal, predicting that a young star close to the red supergeant would explain a regular variation in its brightness. In addition, Another article of November gives radial speed and astronometric evidence of the existence of this close companion.

Bételgeuse. also named a Orionis, is clearly visible to the naked eye in the constellation d’Orion Because it is one of the brightest stars bételgeuse star “friend” who sticks in the sky: its radius is about 700 times higher than that of our sun.

It is customary of such surprises for those who observe it. For five months, between 2019 and 2020, she had pale spectacularly, suggesting an imminent end, an explosion in supernova … Then. observations concluded that a cloud of material ejected by the star and a cooling of its surface to explain the phenomenon.

>> Lire : Astronomers have clarified the mystery of the paleness of the Bételgeuse star

Bételgeuse star &quot. friend" who sticks – Bételgeuse star "friend" who sticks

Two enigmatic light curves

It remained to explain the origin of its two curves of light, the slow pulses of its apparent brightness, which are approximately 400 days respectively for one and almost six years for the other.

The head of the longest light curve is a small star. according to a study NASA astronomers to appear in The Astrophysical Journal.

His scientific name is α Orionis B. but astronomers have nicknamed him Beltelbuddy!

From a mass estimated only once. a half that of our sun, tiny compared to that of Bételgeuse, the star orbit his partner at a relatively low distance, of the order of four times that separating the earth from the sun. It is a hot and young star who has not yet started to burn hydrogen of his heart (Read box).

It is the first detection of an orbit star as close to a super giant star. according to the Noirlab press release, the American organization operating in particular the Gemini International Observatory located in Hawaii, which allowed these observations.

“The studies that predicted Bételgeuse’s companion believed that nobody would probably never be able to imagine him. ” said Steve Howellprincipal researcher at the research center Ames NASA, who led the team behind the bételgeuse star “friend” who sticks discovery.

Direct detection of the small star took time. has been particularly difficult because it is about six times less bright than Bételgeuse. It could be observed thanks to the so -called technique ofInterferometry of tavlingdeveloped in 1970: this consists in assembling fixed. very brief images – of a few milliseconds – of a star to get rid of atmospheric turbulence which disturb the observation with terrestrial telescopes.

Another opportunity to study Betelbuddy will present himself in November 2027. when the little companion returns to his most distant separation from Bételgeuse: it will therefore be easier to detect and astronomers will be able to better determine its nature.

Stéphanie Jaquet and ATS