Epsilon Coronae Australis
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Corona Australis |
| Right ascension | 18h 58m 43.37714s [1] |
| Declination | −37° 06′ 26.4865″ [1] |
| Spectral type | F2V[2] |
Epsilon Coronae Australis (ε CrA), is a star located in the constellation Corona Australis. Epsilon Coronae Australis is also known as HR 7152, and HD 175813.
Epsilon Coronae Australis is an F4V dwarf star with an effective temperature of 6000 Kelvin. It ranges between apparent magnitudes of 4.74 to 5 over 14 hours,[2] an absolute magnitude of +2.45, and a mass of 1.1 solar masses. Epsilon Coronae Australis is an W Ursae Majoris variable, indicating that it has a contact companion within the Roche Limit of the primary. The star is located at a distance of 30 pc (97 light years) from the Sun.[3] Yildiz and colleagues estimated the age of the system at 2.83 ± 0.28 billion years based on study of the properties of the system and estimated rate of mass transfer. They found the current masses of the primary and secondary to be 1.72 ± 0.04 and 0.22 ± 0.02 solar masses respectively, from their original masses of 1.06 ± 0.03 and 2.18 ± 0.06 solar masses.[4]
References
- 1 2 "V* eps CrA -- Eclipsing binary of W UMa type (contact binary)". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 22 January 2014.
- 1 2 BSJ (4 January 2010). "Epsilon Coronae Australis". AAVSO Website. American Association of Variable Star Observers. Retrieved 22 January 2014.
- ↑ Eker, Z.; Bilir, S.; Yaz, E.; Demircan, O.; Helvaci, M. (2009). "New absolute magnitude calibrations for W Ursa Majoris type binaries". Astronomische Nachrichten. 330 (1): 68–77. arXiv:0807.4989
. Bibcode:2009AN....330...68E. doi:10.1002/asna.200811041. - ↑ Yildiz (2014). "Origin of W UMa-type contact binaries - age and orbital evolution". Monthly Notices of the Royal Astronomical Society. 437 (1): 185–94. arXiv:1310.5526. Bibcode:2014MNRAS.437..185Y. doi:10.1093/mnras/stt1874.