Giant Star's Mysterious X-Rays Finally Explained After 50 Years Space
Key summary
Astronomers have discovered that the X-ray emissions from the massive blue star gamma Cassiopeia (γ Cas) are actually from a companion white dwarf siphoning material from it.
The γ Cas system is located 550 light-years away and consists of multiple stars, including a blue-white Be-type star around 15 times the mass of the Sun.
New observations using the XRISM satellite have confirmed that the high-temperature plasma responsible for the X-rays is associated with the white dwarf, not the Be star.
This discovery provides the first direct evidence of the Be-white dwarf binary system, which had been theorized but not confirmed before.
The findings will help scientists update models of binary evolution and improve understanding of interactions between these types of stars.