Astronomers have captured the first image of Betelgeuse's companion star, Betelgeuse B, which is 2-3 times heavier than the Sun. The discovery, published in Astronomy & Astrophysics, solves a long-standing mystery about the star's flickering brightness.
TL;DR
- Astronomers have captured the first image of Betelgeuse's companion star, Betelgeuse B, which is 2-3 times heavier than the Sun.
- The discovery was made using the European Southern Observatory's Very Large Telescope in Chile.
- The companion star's unexpected mass allowed astronomers to spot it despite Betelgeuse's overwhelming brightness.
What happened
Astronomers have unveiled the first image of Betelgeuse's companion star, Betelgeuse B, according to a study published in Astronomy & Astrophysics. The image was captured using the European Southern Observatory's Very Large Telescope in Chile in December 2024.
The companion star was initially thought to have only 1.5 times the Sun's mass, but observations revealed it is significantly heavier, weighing 2-3 times more than the Sun. This increased mass allowed astronomers to spot it despite Betelgeuse's overwhelming brightness, which is 1,000 times bigger than the Sun.
Why it matters
The discovery solves a long-standing mystery about Betelgeuse's flickering brightness, which has been observed for thousands of years by ancient Egyptians and Indigenous Australians. The companion star's orbit around Betelgeuse causes the star's brightness to change in regular cycles.
The findings also provide new insights into the behavior of red supergiant stars and their companions. While more observations are needed to definitively prove the companion's existence, the evidence is compelling, with astronomers stating there is very little space left for doubt.
Key facts
- Betelgeuse is one of the brightest and most famous stars in the night sky, known as the hunter's shoulder in the Orion constellation.
- The companion star, Betelgeuse B, is 2-3 times heavier than the Sun, significantly more than initially thought.
- The image was captured using the European Southern Observatory's Very Large Telescope in Chile in December 2024.
- The study was published in the journal Astronomy & Astrophysics.
- Betelgeuse previously surprised astronomers by dramatically dimming for five months between 2019 and 2020, initially thought to be a sign of an impending supernova explosion.
- Further observations revealed the dimming was caused by a massive amount of material ejected from the surface, creating a dust cloud that blocked the star's light.
Context
Betelgeuse has been a subject of fascination for astronomers and stargazers alike for centuries. Its dramatic dimming events and fluctuating brightness have sparked numerous studies and theories.
The discovery of Betelgeuse B provides a new avenue for understanding the complex interactions between stars and their companions. It also highlights the capabilities of advanced telescopes in uncovering previously hidden celestial phenomena.
As astronomers continue to study Betelgeuse and its companion, they hope to gain deeper insights into the life cycles of red supergiant stars and the dynamics of binary star systems.