TZ Cassiopeiae
Observation data Epoch J2000 Equinox J2000 |
|
---|---|
Constellation | Cassiopeia |
Right ascension | 23h 52m 56.23733s[1] |
Declination | 61° 00′ 08.3786″[1] |
Apparent magnitude (V) | 9.18[2] (+8.86 - +10.5[3]) |
Characteristics | |
Spectral type | M3 Iab[4] |
U−B color index | +2.43[2] |
B−V color index | +2.57[2] |
Variable type | Lc[3] |
Astrometry | |
Radial velocity (Rv) | −54.28[5] km/s |
Proper motion (μ) | RA: −2.77[1] mas/yr Dec.: −3.10[1] mas/yr |
Parallax (π) | 0.39 ± 0.76[1] mas |
Distance | 2,400[6] pc |
Absolute magnitude (MV) | −5.98[7] |
Details | |
Mass | 15[8] M☉ |
Radius | 800[7] R☉ |
Luminosity | 98,000[7] L☉ |
Surface gravity (log g) | −0.1[7] cgs |
Temperature | 3,600[7] K |
Other designations | |
Database references | |
SIMBAD | data |
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 3,600 Kelvin. It is currently around 15 M☉
TZ Cassiopeiae was reported as being variable by Williamina Fleming and published posthumously in 1911.[9] It is a slow irregular variable star with a possible period of 3,100 days.[10] It is approximately 98,000 times the luminosity of the Sun, and it is 800 times bigger than the Sun. It is a member of the Cas OB5 stellar association, together with the nearby red supergiant PZ Cassiopeiae.[11]
TZ Cas is lowing mass through a powerful stellar wind at two millionths of a solar mass each year.[6] 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 supernova, or a Wolf-Rayet star, it will inevitably end its life violently in a supernova explosion.[12]
References
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- ↑ 2.0 2.1 2.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ 7.0 7.1 7.2 7.3 7.4 Lua error in package.lua at line 80: module 'strict' not found.
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