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Eta Canis Majoris
Star in the constellation Canis Major / From Wikipedia, the free encyclopedia
Eta Canis Majoris (η Canis Majoris, abbreviated Eta CMa, η CMa), also named Aludra /əˈluːdrə, əˈljuːdrə/,[10] is a star in the constellation of Canis Major. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.[11]
Quick Facts Observation data Epoch J2000 Equinox J2000, Constellation ...
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Canis Major |
Right ascension | 07h 24m 05.70228s[1] |
Declination | –29° 18′ 11.1798″[1] |
Apparent magnitude (V) | 2.450[2] |
Characteristics | |
Spectral type | B5 Ia[3] |
U−B color index | −0.708[2] |
B−V color index | −0.087[2] |
Variable type | α Cyg[4] |
Astrometry | |
Radial velocity (Rv) | 41.1[5] km/s |
Proper motion (μ) | RA: −4.14[1] mas/yr Dec.: 5.81[1] mas/yr |
Parallax (π) | 1.64 ± 0.40 mas[1] |
Distance | approx. 2,000 ly (approx. 600 pc) |
Absolute magnitude (MV) | −7.0[6] |
Details | |
Mass | 18.19[7] M☉ |
Radius | 54[8] R☉ |
Luminosity | 135,000 - 174,000[8] L☉ |
Surface gravity (log g) | 2.00[8] cgs |
Temperature | 15,000 - 16,000[8] K |
Rotational velocity (v sin i) | 40[8] km/s |
Age | 8.3[9] Myr |
Other designations | |
Database references | |
SIMBAD | data |
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