Betelgeuse‘s Companion Star Defies Expectations, New X-Ray Data Reveals
Astronomers have solved a long-standing mystery surrounding Betelgeuse, the red supergiant star in Orion, discovering its companion star is not a massive object like a white dwarf or neutron star as previously suspected. Rather, detailed analysis of X-ray data indicates the companion, dubbed Siwarha, is a young, Sun-like F-type star. the findings, published in The Astrophysical Journal, challenge current understanding of how binary star systems form and evolve.
This revelation is important because it reveals an unexpectedly extreme mass ratio in a binary system – a massive, dying star orbiting a much smaller, younger one. Current stellar evolution models predict stars born together should have more similar masses.The unusual pairing of Betelgeuse and Siwarha suggests these models may need refinement,perhaps impacting our understanding of star formation and the lifecycles of binary systems,which are common throughout the galaxy.
Researchers led by Maria O’Grady of the Carnegie Mellon University analyzed data from the Chandra X-ray Observatory, finding no detectable X-rays emanating from Siwarha. This ruled out the presence of a dense remnant star like a white dwarf or neutron star, which would be expected to produce significant X-ray emissions. “Even assuming that the wind gusting out of Betelgeuse had obscured some of the X-rays, the non-detection rules out a white dwarf or neutron star,” the team explained.
The data suggests Siwarha is likely an F-type star, potentially still settling onto the main sequence, and formed approximately 10 million years ago alongside Betelgeuse. However, due to its smaller mass, Siwarha is in the early stages of its life while Betelgeuse is nearing the end, poised to eventually explode as a supernova.
“This opens up a new regime of extreme mass ratio binaries,” O’grady says. “it’s an area that hasn’t been explored much because it’s so challenging to find them or to even identify them like we were able to do with Betelgeuse.” Further study of this unusual binary system promises to provide valuable insights into the diverse ways stars can form and interact.
