Epsilon Apodis
{{Short description|Star in the constellation Apus}}
{{Starbox begin
| name = ε Apodis
}}
{{Starbox image
| image=
{{Location mark
|image=Apus constellation map.svg|alt=|float=center|width=260
|label=|position=right
|mark=Red circle.svg|mark_width=10|mark_link=ε Apodis
|x=648|y=720
}}
|caption=Location of ε Apodis (circled)
}}
{{Starbox observe
| epoch = J2000
| dec = {{DEC|−80|06|32.2053}}
| constell = Apus
}}
{{Starbox character
| variable = γ Cas
}}
{{Starbox astrometry
| parallax = 5.06
| p_error = 0.22
}}
{{Starbox detail
| temperature = 17,100{{±|171}}
| rotational_velocity = 150{{±|3}}
}}
{{Starbox catalog
| names = {{odlist | B=ε Aps | CD=-79°559 | HD=124771 | HIP=70248 | HR=5336 | SAO=257142 }}
}}
{{Starbox reference
| Simbad=eps+Aps
}}
{{Starbox end}}
Epsilon Apodis is a star in the southern circumpolar constellation of Apus. Its identifier is a Bayer designation that is Latinized from ε Apodis, and abbreviated Eps Aps or ε Aps, respectively. This star has an apparent visual magnitude of 5.06, which is bright enough to be viewed from dark suburban skies. Based upon parallax measurements, it is at a distance of roughly {{Convert|640|ly|pc|abbr=off|lk=on}} from Earth. The star is drifting further away with a heliocentric radial velocity of +4.5 km/s.
File:EpsilonApsLightCurve.png for Epsilon Apodis, plotted from Hipparcos data]]
Based upon a stellar classification of B3 V, this is a massive, B-type main sequence star that is generating energy through the fusion of hydrogen at its core. Epsilon Apodis has more than six times the mass of the Sun and over four times the Sun's radius. It is radiating 1,614 times as much luminosity as the Sun from its photosphere at an effective temperature of 17,100 K. At this heat, it has a blue-white glow that is a characteristic of B-type stars.
Epsilon Apodis is spinning rapidly, with a projected rotational velocity of 150 km/s giving a lower bound for the azimuthal velocity along the equator. Epsilon Apodis is classified as a Gamma Cassiopeiae type variable star and its brightness varies between magnitudes 4.99 and 5.04.
Naming
In Chinese caused by adaptation of the European southern hemisphere constellations into the Chinese system, {{lang|zh|異雀}} ({{lang|zh-Latn|Yì Què}}), meaning Exotic Bird, refers to an asterism consisting of ε Apodis, ζ Apodis, ι Apodis, β Apodis, γ Apodis, δ Octantis, δ1 Apodis, η Apodis and α Apodis. Consequently, ε Apodis itself is known as {{lang|zh|異雀九}} ({{lang|zh-Latn|Yì Què jiǔ}}, {{langx|en|the Ninth Star of Exotic Bird}}.)
References
{{reflist|30em|refs=
| 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 | s2cid=119257644 | postscript=. }}
| title=Stellar parameters and H α line profile variability of Be stars in the BeSOS survey
| last1=Arcos | first1=C. | last2=Kanaan | first2=S.
| last3=Chávez | first3=J. | last4=Vanzi | first4=L.
| last5=Araya | first5=I. | last6=Curé | first6=M.
| journal=Monthly Notices of the Royal Astronomical Society
| volume=474 | issue=4 | pages=5287–5299 | date=March 2018
| doi=10.1093/mnras/stx3075 | doi-access=free
| arxiv=1711.08675
| bibcode=2018MNRAS.474.5287A | display-authors=1 }}
{{citation | last1=Evans | first1=D. S. | date=June 20–24, 1966 | editor1-last=Batten | editor1-first=Alan Henry | editor2-last=Heard | editor2-first=John Frederick | contribution=The Revision of the General Catalogue of Radial Velocities | title=Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 | volume=30 | page=57 | location=University of Toronto | publisher=International Astronomical Union | bibcode=1967IAUS...30...57E | postscript=. }}
{{citation | last1=Tetzlaff | first1=N. | last2=Neuhäuser | first2=R. | last3=Hohle | first3=M. M. | title=A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun | journal=Monthly Notices of the Royal Astronomical Society | volume=410 | issue=1 | pages=190–200 |date=January 2011 | doi=10.1111/j.1365-2966.2010.17434.x | doi-access=free | bibcode=2011MNRAS.410..190T | postscript=. |arxiv = 1007.4883 | s2cid=118629873 }}
{{citation | title=eps Aps -- Be Star | work=SIMBAD | publisher=Centre de Données astronomiques de Strasbourg | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+124771 | accessdate=2012-07-08 | postscript=. }}
{{citation |title=The Colour of Stars |date=December 21, 2004 |work=Australia Telescope, Outreach and Education |publisher=Commonwealth Scientific and Industrial Research Organisation |url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html |accessdate=2012-01-16 |postscript=. |url-status=dead |archiveurl=https://web.archive.org/web/20120318151427/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html |archivedate=2012-03-18 }}
{{citation | last1=Samus | first1=N. N. | last2=Durlevich | first2=O. V. | last3=Kazarovets | first3=R. V. | title=eps Aps | work=General Catalogue of Variable Stars | publisher=Sternberg Astronomical Institute | url=http://www.sai.msu.su/gcvs/cgi-bin/ident.cgi?cat=HD++&num=124771 | accessdate=2012-07-09 | postscript=. }}
}}
External links
- [http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Epsilon+Apodis&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id Simbad]
- [http://aladin.u-strasbg.fr/AladinPreview?-c=14+22+23.1600-80+06+32.203&ident=*+eps+Aps&submit=Aladin+previewer Image Epsilon Apodis]
{{Stars of Apus}}
{{DEFAULTSORT:Epsilon Apodis}}
Category:B-type main-sequence stars
Category:Gamma Cassiopeiae variable stars