The Search Is On for Betel-Buddy

The image above shows a size comparison: Betelgeuse and the sun. Credit: ESO

Betelgeuse is one of the most well-known stars in the night sky. Located about 640 light years from Earth in the constellation Orion, it’s a red supergiant nearing the end of its life, destined to explode as a supernova. It’s now over 700 times the size of the sun and has captivated astronomers with its unpredictable brightness.

In late 2019, it dimmed dramatically, sparking speculation that it might be on the verge of exploding. While that event turned out to be a massive dust cloud temporarily blocking its light, it highlighted how volatile this dying star truly is.

Betelgeuse belongs to a fascinating category of stellar objects that exhibit puzzling behavior. About one third of cool, luminous stars with large convective envelopes like Betelgeuse display long-term brightness variations known as Long Secondary Periods (LSPs).

For decades, astronomers have debated what causes these fluctuations, proposing various theories including internal pulsations, surface dust formation, and giant convection cells within the star. However, recent research has begun to converge on a more intriguing explanation: Betelgeuse may not be alone. The paper is published on the arXiv preprint server.

The evidence increasingly points toward the presence of a low-mass companion star orbiting the red supergiant every approximately 2,100 days (roughly six years) at a distance comparable to Saturn’s orbit around the sun. The hypothetical companion star would have a mass ranging from 0.5 to two times that of the sun.

(Source: phys.org)