A team of astronomers led by astrophysicist Steven Howell managed to photograph for the First time in history the “companion” hidden by the star Bettelgeusethe brilliant red supergiant star located in the left “shoulder” of the Constellation of Orion (“Betelgeuse” literally means “the giant’s hand”). The discovery was obtained using the Gemini North telescopelocated on Mount Maunakea in Hawaii, thanks to a technique known as speckle imaging which made it possible to find the weak partner, of mass equal to 1.5 times That of the sun, hidden by the blinding light of the star Betelgeuse. The star orbit to about 4 astronomical units by Bettelgeuse, practically lambing the atmospherethus solving the secular enigma on the 6 -year periodicity in the light curve of the red supergiant.
How the Betelgeuse Star was discovered
Telescope Gemini Northlocated on Mount Maunakea in Hawaii, he succeeded where more famous telescopes, such as the Hubble space telescope, have failed: to resume one Direct image of the hypothesized star Betelgeuse partner. The discovery was possible using the tool ‘Alopeke (which in Hawaiian means fox) and the technique of speckle imaging. The technique consists in resuming a very high number of imagesall with very short exposure times. The latter must be lower than what are i Typical times of variation of atmospheric turbulencearound the hundredth of a second. In doing so, every short exposure is as if one resumed instantaneous of atmospheric turbulence, By increasing angular resolution observation (that is, allowing to resume very close subjects angularly with each other). Longer exposure times, in addition to saturating the room because of the brightness of Belgeuse, would mediate on a higher number of variations of the atmospheric turbulence, transforming the two stars into an indistinguishable single Blob.
What do we know about the Bettelgeuse system
The star Betelgeuse It is found in the constellation of Orion that dominates the winter skies of the boreal hemisphere. It is a star Red Supergianttwenty times more massive than the sun and with such a great diameter that its atmosphere would lain the orbit of Jupiter, if it were in the solar system. Betelgeuse is relatively young, 8.5 million yearsbut given its great mass, it is “soon” destined to explode as supernova, with a brightness that would make it visible from the earth even in broad daylight.
Being so brilliant, it has been studied for centuries and is well known as hers Various brightness on two cycles of 400 days and 6 years. In recent years, 2019 and 2020, a sudden decrease in brightness He seemed to announce the imminent explosion in supernova, only to be discovered that the decrease was caused by one expulsion of dust by the star itself. The 6 -year -old cycle has always aroused suspicions in astronomers, which for years for years hypothesize that the star could have one partner in narrow orbit around it.
Thanks to the Gemini North telescope on secular mystery of the variation of brightness of Betelgeuse was resolved. It has one Star StarOf mass equal to 1.5 times the mass of the sun, which orbit around Bettelgeuse at a distance of about 4 astronomical unitsalmost the surface launching. From the images obtained it is noted that the color of the object is Blue more than that of Bettelgeusea sign of one major surface temperature of the partner. The orbital distance of this second object is fully compatible with the cycle of 6 years of variation of brightness of betelgeuse. TO November 2027the partner will reach the maximum corner distance from Belgeuse, thus allowing astronomers to better understand the nature of the “hidden” partner for centuries of Bettelgeuse.
