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Astronomers Uncover White Dwarf Mystery in Gamma-Cas System

3/27/2026

Summary

Story summary

Astronomers resolved a 50-year mystery about gamma-Cas in the Cassiopeia constellation by linking X-rays to a white dwarf companion.
The XRISM space telescope confirmed the X-ray emission arises from the white dwarf accreting material.
Yaël Nazé of the University of Liège led the study identifying gamma-Cas as part of a new Be-star–white-dwarf binary class.
The findings suggest such binaries are rarer than expected and were published in Astronomy & Astrophysics.

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Story summary

Astronomers resolved a 50-year mystery about gamma-Cas in the Cassiopeia constellation by linking X-rays to a white dwarf companion.
The XRISM space telescope confirmed the X-ray emission arises from the white dwarf accreting material.
Yaël Nazé of the University of Liège led the study identifying gamma-Cas as part of a new Be-star–white-dwarf binary class.
The findings suggest such binaries are rarer than expected and were published in Astronomy & Astrophysics.