Eta Piscis Austrini
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Piscis Austrinus |
Right ascension | 22h 00m 50.22537s[1] |
Declination | −28° 27′ 13.4639″[1] |
Apparent magnitude (V) | +5.43[2] (5.742 + 6.825)[3] |
Characteristics | |
Spectral type | B8 V[4] or B7 IVe[5] |
U−B color index | −0.30[2] |
B−V color index | −0.10[2] |
Astrometry | |
Proper motion (μ) | RA: +15.57[1] mas/yr Dec.: −1.03[1] mas/yr |
Parallax (π) | 3.99 ± 0.48 mas[1] |
Distance | approx. 820 ly (approx. 250 pc) |
Absolute magnitude (MV) | −1.53[5] |
Details | |
η PsA A | |
Mass | 4.01±0.18[4] M☉ |
Luminosity | 604[4] L☉ |
Surface gravity (log g) | 3.84[6] cgs |
Temperature | 11,272[4] K |
Rotational velocity (v sin i) | 265[4] km/s |
Age | 115[6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Eta Piscis Austrini (η Piscis Austrini) is binary star[3] system in the southern constellation of Piscis Austrinus. As of 2000, the two components had an angular separation of 1.818 arc seconds along a position angle of 113.4°. The pair have a combined apparent visual magnitude of +5.43,[2] which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 3.99 mas as seen from the Earth,[1] the system is located roughly 820 light years from the Sun.
The magnitude 5.7 primary, component A,[3] is a blue-white hued Be star[6] with a stellar classification B8 V.[4] At the age of 115,[6] the star is spinning rapidly with a projected rotational velocity of 265.[4] It has an estimated four times the mass of the Sun and is radiating 604 times the solar luminosity at an effective temperature of 11,272 K.[4] The secondary, component B, has a visual magnitude of 6.8.[3]
Eta Piscis Austrini is moving through the Galaxy at a speed of 11.3 km/s relative to the Sun. Its projected Galactic orbit carries it between 23,600 and 30,800 light years from the center of the Galaxy.[8][unreliable source?]
References
- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d Feinstein, A.; Marraco, H. G. (November 1979), "The photometric behavior of Be Stars", Astronomical Journal, 84: 1713–1725, Bibcode:1979AJ.....84.1713F, doi:10.1086/112600.
- ^ a b c d Fabricius, C.; Makarov, V. V. (April 2000), "Two-colour photometry for 9473 components of close Hipparcos double and multiple stars", Astronomy and Astrophysics, 356: 141–145, Bibcode:2000A&A...356..141F.
- ^ a b c d e f g h Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
- ^ a b Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c d Zorec, J.; et al. (October 2005), "On the evolutionary status of Be stars. I. Field Be stars near the Sun", Astronomy and Astrophysics, 441 (1): 235–248, arXiv:astro-ph/0509119, Bibcode:2005A&A...441..235Z, doi:10.1051/0004-6361:20053051, S2CID 17592657.
- ^ "eta PsA -- Be Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-05-18.
- ^ Eta Piscis Austrini (HIP 108661)
- Articles with short description
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- All articles lacking reliable references
- Articles lacking reliable references from May 2017
- A-type main-sequence stars
- Binary stars
- Bayer objects
- Piscis Austrinus
- Durchmusterung objects
- Flamsteed objects
- Henry Draper Catalogue objects
- Hipparcos objects
- Bright Star Catalogue objects