| absmag_v = −1.53[6]
}}{{Starbox detail
| source =
| component1 = η PsA A
| mass = {{Val|4.01|0.18}}[5]
| radius =
| luminosity = 604[5]
| temperature = 11,272[5]
| gravity = 3.84[16]
| metal_fe =
| rotational_velocity = 265[5]
| age_myr = 115[16]
}}{{Starbox catalog
| names = η PsA, 12 Piscis Austrini, CPD−29° 6659, HD 209014, HIP 108661, HR 8386, SAO 190822, WDS J22008-2827AB[19]
}}{{Starbox reference
| Simbad = eta+PsA
}}{{Starbox end}}Eta Piscis Austrini (η Piscis Austrini) is binary star[4] 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,[3] 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,[ the system is located roughly 820 light years from the Sun.]
The magnitude 5.7 primary, component A,[4] is a blue-white hued Be star[16] with a stellar classification B8 V.[5] At the age of 115,[16] the star is spinning rapidly with a projected rotational velocity of 265.[5] 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.[5] The secondary, component B, has a visual magnitude of 6.8.[4]
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.[1]{{Unreliable source?|date=May 2017}}
References
1. ^Eta Piscis Austrini (HIP 108661)
2. ^1 2 {{citation | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | postscript=. }}
3. ^1 2 3 4 {{citation | last1=Feinstein | first1=A. | last2=Marraco | first2=H. G. | title=The photometric behavior of Be Stars | journal=Astronomical Journal | postscript=. | volume=84 | pages=1713–1725 | date=November 1979 | doi=10.1086/112600 | bibcode=1979AJ.....84.1713F }}
4. ^1 2 3 4 5 6 7 8 {{citation | last1=Zorec | first1=J. | last2=Royer | first2=F. | title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities | journal=Astronomy & Astrophysics | volume=537 | page=A120 | date=January 2012 | doi=10.1051/0004-6361/201117691 | bibcode=2012A&A...537A.120Z | arxiv=1201.2052 | postscript=. }}
5. ^1 2 3 4 {{citation | title=On the evolutionary status of Be stars. I. Field Be stars near the Sun | display-authors=1 | last1=Zorec | first1=J. | last2=Frémat | first2=Y. | last3=Cidale | first3=L. | journal=Astronomy and Astrophysics | volume=441 | issue=1 | date=October 2005 | pages=235–248 | doi=10.1051/0004-6361:20053051 | bibcode=2005A&A...441..235Z | arxiv=astro-ph/0509119 | postscript=. }}
6. ^1 2 3 4 {{citation | last1=Fabricius | first1=C. | last2=Makarov | first2=V. V. | title=Two-colour photometry for 9473 components of close Hipparcos double and multiple stars | journal=Astronomy and Astrophysics | volume=356 | pages=141–145 | date=April 2000 | bibcode=2000A&A...356..141F | postscript=. }}
7. ^1 {{citation | title=eta PsA -- Be Star | work=SIMBAD Astronomical Database | publisher=Centre de Données astronomiques de Strasbourg | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=eta+PsA | accessdate=2017-05-18 | postscript=. }}