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Betelgeuse's New Companion Star Challenges Binary Formation Theories

10/16/2025

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Summary

Story summary

Betelgeuse has a confirmed companion star named Siwarha, which is a young Sun-like star rather than a white dwarf or neutron star.
The two stars likely formed together about 10 million years ago.
The 16–19 solar-mass Betelgeuse and the ~1 solar-mass Siwarha reveal a mass ratio that challenges existing binary star formation models.
The discovery opens new avenues for studying extreme mass-ratio binaries, a largely unexplored area in astronomy.

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Story summary

Betelgeuse has a confirmed companion star named Siwarha, which is a young Sun-like star rather than a white dwarf or neutron star.
The two stars likely formed together about 10 million years ago.
The 16–19 solar-mass Betelgeuse and the ~1 solar-mass Siwarha reveal a mass ratio that challenges existing binary star formation models.
The discovery opens new avenues for studying extreme mass-ratio binaries, a largely unexplored area in astronomy.