Epsilon Ursae Minoris
From Wikipedia, the free encyclopedia
Observation data Epoch J2000.0 |
|
---|---|
Constellation (pronunciation) |
Ursa Minor |
Right ascension | 16h 45m 58.1s |
Declination | +82° 02' 14" |
Apparent magnitude (V) | +4.21 |
Distance | 347 ± 25 ly (106 ± 8 pc) |
Spectral type | G5III |
Other designations | |
Epsilon Ursae Minoris (ε UMi / ε Ursae Minoris) is a triple star system in the constellation Ursa Minor. It is approximately 347 light years from Earth. Epsilon Ursae Minoris also carries the seldom used proper name Urodelus, Greek for "Conspicuous Tail" of the Bear or Dog.
The primary component, Epsilon Ursae Minoris A, is an eclipsing spectroscopic binary. It is classified as a yellow G-type giant with a mean apparent magnitude of +4.21. In addition to light changes due to eclipses, the system is also classified as an RS Canum Venaticorum type variable star and its brightness varies from magnitude +4.19 to +4.23 with a period of 39.48 days, which is also the orbital period of the binary. The binary it orbited by a third component, Epsilon Ursae Minoris B, which is an 11th magnitude star, 77 arcseconds away on the sky.