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Epsilon Coronae Australis
Variable star in the constellation Corona Australis / From Wikipedia, the free encyclopedia
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Epsilon Coronae Australis (ε CrA), is a star system located in the constellation Corona Australis. Varying in brightness between apparent magnitudes of 4.74 to 5 over 14 hours, it is the brightest W Ursae Majoris variable (low mass contact binary) in the night sky.
Quick Facts Constellation, Right ascension ...
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Corona Australis |
Right ascension | 18h 58m 43.37714s[2] |
Declination | −37° 06′ 26.4865″[2] |
Apparent magnitude (V) | +4.75[3] |
Characteristics | |
Spectral type | F4V Fe-0.8[4] |
U−B color index | +0.01[3] |
B−V color index | +0.39[3] |
Variable type | W UMa[5] |
Astrometry | |
Radial velocity (Rv) | 57.90 ± 1.2[6] km/s |
Proper motion (μ) | RA: −132.40[2] mas/yr Dec.: −110.62[2] mas/yr |
Parallax (π) | 33.13 ± 0.33 mas[2] |
Distance | 98.4 ± 1.0 ly (30.2 ± 0.3 pc) |
Absolute magnitude (MV) | 2.21[7] |
Orbit[8] | |
Period (P) | 0.59143357 ± 0.00000016 d |
Semi-major axis (a) | 3.795 ± 0.052 R☉ |
Eccentricity (e) | 0 |
Inclination (i) | 73.05 ± 0.16° |
Longitude of the node (Ω) | 2.0113 ± 0.0033° |
Periastron epoch (T) | JD 2442296.95907 ± 0.0070 |
Details | |
ε CrA A | |
Mass | 1.9[8] M☉ |
Radius | 2.167[8][note 1] R☉ |
Temperature | 6481 ± 20[8] K |
Rotational velocity (v sin i) | 148.5[9] km/s |
ε CrA B | |
Mass | 0.24[8] M☉ |
Radius | 0.869[8][note 1] R☉ |
Temperature | 5939 ± 19[8] K |
Other designations | |
Database references | |
SIMBAD | data |
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