Betlegeuze is one of the shoulder stars of Orion and one of the brightest stars in the night sky. Now astronomers have discovered a partner star of this red. With the help of the Gemini North Telescope in Hawaii, they managed to prove and map this much smaller, light -wealther companion for the first time. This discovery explains why Betägeuze changes its brightness every almost six years. The newly discovered accompanying star is only around 1.5 solar masses heavy and shines bluish. Unlike Betleigeuze, he is still at the beginning of his life cycle. Nevertheless, this star will not last long because the gravity of its far more massive partner attracts him. In around 10,000 years, Betägeuz’s accompanying star will therefore be destroyed by the tidal forces of the Red Tower, as the astronomers report.
Betlegeuze is only 650 light years from us in the Orion constellation. The red tuning has a diameter of around 700 times and the more than ten thousand times the luminosity of our sun. In the night sky he shines as the tenth star. Betägeuze is only around ten million years old and is still young after Stellar. Nevertheless, he is already approaching his end: Due to his large mass of 16 to 19 solar masses, he quickly consumed his fusion fuel and has already bloated enormously. Astronomers assume that the outdoor giant could soon explode in a supernova, when this will be the case, whether in a few years, centuries or millennia, but is unknown. In 2019, Betägeuze caused a sensation because his brightness suddenly decreased very much. Astronomers first saw this as the first sign of a supernova, but further observations then showed that a huge plasma eruption had created a darkening dust cloud.
Tracked down thanks to Speckle-Imming
Now astronomers have found the solution to another puzzle around Betlegeuze. In addition to an activity cycle of around 400 days based on internal processes, the outdoors also show brightness fluctuations that fluctuate with almost six years. These so -called long secondary period (LSP) of this and some other outdoors cannot be explained with well -known mechanisms and cycles of star activity. Therefore, astronomers have long suspected that Betlegeuze may have an accompanying star. According to the first indications, the latter would have to circle the red torch, around 20 times lighter and around one million times light weaknesses. This could explain why this small, close partner star has not yet been discovered despite the intensive, decades of observations by the prominent giant star: the much lighter, larger boredian is completely outshone.
Nevertheless, a team around Steve Howell from the AMES Research Center of NASA has now managed to demonstrate the accompanying star of the Betägeuze and to map them for the first time. This was made possible by a favorable position of the two stars in June 2024, which at that time had a particularly large distance from us to track down the light-tuning companion next to the bright output, the astronomers used the so-called Speckle image at Gemini North Telescope in Hawaii. This instrument allows a lot of recordings with a short exposure time to create directly in a row – quasi ultra -short snapshots. These images are then combined in such a way that the interference effects of the earth’s atmosphere can be calculated and particularly sharp, high -contrast recordings are created.
(Video: Noirab Astro)
Young, bluish and soon destroyed
Through this technology, the astronomer team managed to map the long -looking partner star of Betlegeuze. It is the first time that a closely surrounding partner star of an output could be made visible. “The high angle resolution of Gemini North and his sharp contrasts made it possible to prove Betäneuzes companion directly,” explains Howell. The recordings confirm that the partner star of the Betleigeuze has less than a tenth of the red outer outer output, it is only difficult for around 1.5 solar masses. In the visible light, the companion also appears six magnitudes as a prayer and does not shine reddish, but rather bluish, as the astronomers report. The proof of this small accompanying star now also provides the explanation for the long -periodian brightness fluctuations from Betleigeuze: his small, darker companion regularly passes in front of his larger, lighter partner and influences its brightness. “The solution to the centuries-old Betelgeuse problem is an impressive highlight and will be remembered for a long time,” comments Martin Still, program director for the Gemini Observatory from the US National Science Foundation.
The small mass of the newly discovered partner star has several consequences for this compared to Betlegeuze. On the one hand, the companion has developed far more slowly than the red tuning: While it has already reached the end of his stellar life cycle, the accompanying star is even a hot, bluish young star whose core fusion has just started. Nevertheless, his days are also counted: the strong attraction of his larger partner is approaching the smaller accompanying star closer and closer to Betägeu. According to estimates by the astronomers, the smaller partner could come so close to the outdoors in the next 10,000 years that he is torn by his enormous tidal forces.
Source: Steve Howell (Ames Research Center, California) et al., The Astrophysical Journal Letters, DOI: 10.3847/2041-8213/ADEAAF
