Astronomers Confirm Betelgeuse Has 2.6-3.1-Solar-Mass Companion as VLT Images Resolve Binary
Updated
Updated · ZME Science · Jul 29
Astronomers Confirm Betelgeuse Has 2.6-3.1-Solar-Mass Companion as VLT Images Resolve Binary
3 articles · Updated · ZME Science · Jul 29
Summary
VLT observations from December 2024 revealed a faint source 0.052 arcseconds from Betelgeuse, giving the clearest evidence yet that the red supergiant has a companion dubbed Betelgeuse B.
Two independent image-processing methods recovered the object from Betelgeuse’s glare at 6.1-sigma and 5.1-sigma significance after astronomers modeled and subtracted distortions from the star, atmosphere and telescope.
Betelgeuse B appears to be a hot young main-sequence star with 2.6 to 3.1 times the Sun’s mass, orbiting at roughly Saturn’s distance from the Sun—larger than earlier estimates of about one solar mass.
The find helps explain Betelgeuse’s roughly 2,200-day long secondary period, a six-year brightness cycle that had long pointed to an unseen partner.
Astronomers still need to track the object through its orbit to prove the pair are gravitationally bound, but the result could help uncover companions around other red supergiants, 20% to 40% of which are currently known binaries.