Magnitude 9.18 Apparent magnitude (V) 9.18 Distance 2,400 pc | Constellation Cassiopeia Absolute magnitude (MV) −5.98 | |
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Similar Chi Cassiopeiae, Lambda Cassiopeiae, Omicron Cassiopeiae, Psi Cassiopeiae | ||
TZ Cassiopeaie (TZ Cas, HIP 117763, SAO 20912) is a variable star in the constellation Cassiopeia with an apparent magnitude of around +9 to +10. It is approximately 8,000 light-years away from Earth. The star is a red supergiant star with a spectral type of M3 and a temperature of 3,670 Kelvin. It is currently around 15 M☉
TZ Cassiopeiae was reported as being variable by Williamina Fleming and published posthumously in 1911. It is a slow irregular variable star with a possible period of 3,100 days. It is approximately 69,000 times the luminosity of the Sun, and it is 645 times bigger than the Sun. It is a member of the Cas OB5 stellar association, together with the nearby red supergiant PZ Cassiopeiae.
TZ Cas is losing mass through a powerful stellar wind at two millionths of a solar mass each year. It is unclear whether this is sufficient to cause the star to lose its atmosphere and become a blue supergiant before the core exhausts its fuel and collapses as a supernova. Either as a red or blue supergiant, or a Wolf-Rayet star, it will inevitably end its life violently in a supernova explosion when the core collapse occurs.