W Coronae Borealis

W Coronae Borealis (W CrB) is a Mira-type long period variable star in the constellation Corona Borealis located about 7,800 light-years away. Its apparent magnitude varies between 7.8 and 14.3 over 238 days (8 months),^[8] representing about a 400–fold change in brightness. W Coronae Borealis enters solar conjunction and becomes hidden by the Sun's glare in late November. It reaches opposition in late April, when it is visible all night.

ConstellationCorona Borealis

Right ascension16^h 15^m 24.549^s[2]

Declination+37° 47′ 44.21″^[2]

Apparentmagnitude(V)7.8 - 14.3^[3]

Quick facts Constellation, Right ascension ...

W Coronae Borealis

The visual band light curve of W Coronae Borealis, from AAVSO data[1]
Observation data Epoch J2000      Equinox ICRS
Constellation	Corona Borealis
Right ascension	16h 15m 24.549s[2]
Declination	+37° 47′ 44.21″[2]
Apparent magnitude (V)	7.8 - 14.3[3]
Characteristics
Evolutionary stage	AGB[4]
Spectral type	M2e-M5e[3]
Variable type	mira[3]
Astrometry
Proper motion (μ)	RA: −9.527[2] mas/yr Dec.: −6.275[2] mas/yr
Parallax (π)	0.4201±0.0447 mas[2]
Distance	approx. 7,800 ly (approx. 2,400 pc)
Details
Mass	3.9[5] M☉
Radius	404[2] R☉
Luminosity	6,088[6] L☉
Surface gravity (log g)	1.38[5] cgs
Temperature	3,981[5] K
Other designations
HD 146560[7]
Database references
SIMBAD	data

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