{{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 | ra = {{RA|14|22|23.16467}}<ref name=aaa474_2_653/> | dec = {{DEC|−80|06|32.2053}}<ref name=aaa474_2_653/> | appmag_v = 5.06<ref name=apjs15_459/> | constell = Apus<ref name=Anderson2012/> }} {{Starbox character | class = B3 V<ref name=houk1979/> | b-v = −0.121<ref name=apjs15_459/> | u-b = −0.610<ref name=apjs15_459/> | variable = γ Cas<ref name=ibvs4659_1/> }} {{Starbox astrometry | radial_v = +4.5{{±|4.2}}<ref name=rgcrv/> | prop_mo_ra = −9.51<ref name=aaa474_2_653/> | prop_mo_dec = −14.34<ref name=aaa474_2_653/> | parallax = 5.06 | p_error = 0.22 | parallax_footnote = <ref name=aaa474_2_653/> | absmag_v = −1.41<ref name=Anderson2012/> }} {{Starbox detail | mass = {{val|6.15|0.71}}<ref name=an331_4_349/> | radius = 4.30{{±|0.09}}<ref name=Arcos_et_al_2018/> | luminosity = 1,614<ref name=an331_4_349/> | temperature = 17,100{{±|171}}<ref name=Arcos_et_al_2018/> | metal_fe = −0.02<ref name=aaa490_1_297/> | gravity = 3.50{{±|0.04}}<ref name=Arcos_et_al_2018/> | rotational_velocity = 150{{±|3}}<ref name=Arcos_et_al_2018/> | age_myr = 38.3{{±|4.4}}<ref name=mnras410_1_190/> }} {{Starbox catalog | names = {{odlist | B=ε Aps | CD=-79°559 | HD=124771 | HIP=70248 | HR=5336 | SAO=257142 }}<ref name=simbad/> }} {{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,<ref name=apjs15_459/> 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.<ref name=aaa474_2_653/> The star is drifting further away with a heliocentric radial velocity of +4.5 km/s.<ref name=rgcrv/>
[[File:EpsilonApsLightCurve.png|thumb|left|A light curve for Epsilon Apodis, plotted from ''Hipparcos'' data<ref name=HipDataAccess/>]] Based upon a stellar classification of B3 V,<ref name=houk1979/> 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<ref name=an331_4_349/> times the mass of the Sun and over four<ref name=Arcos_et_al_2018/> times the Sun's radius. It is radiating 1,614<ref name=an331_4_349/> times as much luminosity as the Sun from its photosphere at an effective temperature of 17,100 K.<ref name=Arcos_et_al_2018/> At this heat, it has a blue-white glow that is a characteristic of B-type stars.<ref name=csiro/>
Epsilon Apodis is spinning rapidly, with a projected rotational velocity of 150 km/s<ref name=Arcos_et_al_2018/> giving a lower bound for the azimuthal velocity along the equator. Epsilon Apodis is classified as a Gamma Cassiopeiae type<ref name=ibvs4659_1/> variable star and its brightness varies between magnitudes 4.99 and 5.04.<ref name=gcvs/>
==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, δ<sup>1</sup> 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}}.)<ref name=AEEA/>
==References== {{reflist|30em|refs=
<ref name=aaa474_2_653>{{citation | first=F. | last=van Leeuwen |date=November 2007 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | postscript=. |arxiv = 0708.1752 | s2cid=18759600 }}</ref>
<ref name=AEEA>{{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0607/ap060729.html AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 29 日] {{Webarchive|url=https://web.archive.org/web/20110522124325/http://aeea.nmns.edu.tw/2006/0607/ap060729.html |date=2011-05-22 }}</ref>
<ref name=Anderson2012>{{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 | s2cid=119257644 | postscript=. }}</ref>
<ref name=Arcos_et_al_2018>{{citation | 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 }}</ref>
<ref name=houk1979>{{citation | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=1 | last1=Houk | first1=Nancy | publication-place=Ann Arbor, Michigan | publisher=Dept. of Astronomy, University of Michigan | date=1979 | bibcode=1978mcts.book.....H | postscript=. }}</ref>
<ref name=HipDataAccess>{{cite web |title=Hipparcos Tools Interactive Data Access |url=https://www.cosmos.esa.int/web/hipparcos/interactive-data-access |website=Hipparcos |publisher=ESA |access-date=8 December 2021}}</ref>
<ref name=rgcrv>{{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=. }}</ref>
<ref name=apjs15_459>{{citation | last1=Gutierrez-Moreno | first1=Adelina | last2=Moreno | first2=Hugo | title=A photometric investigation of the Scorpio-Centaurus association | journal=Astrophysical Journal Supplement | volume=15 | page=459 |date=June 1968 | bibcode=1968ApJS...15..459G | doi=10.1086/190168 | postscript=. | doi-access=free }}</ref>
<ref name=an331_4_349>{{citation | last1=Hohle | first1=M. M. | last2=Neuhäuser | first2=R. | last3=Schutz | first3=B. F. | title=Masses and luminosities of O- and B-type stars and red supergiants | journal=Astronomische Nachrichten | volume=331 | issue=4 | page=349 |date=April 2010 | doi=10.1002/asna.200911355 | bibcode=2010AN....331..349H | postscript=. |arxiv = 1003.2335 | s2cid=111387483 }}</ref>
<ref name=mnras410_1_190>{{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 }}</ref>
<ref name=aaa490_1_297>{{citation | display-authors=1 | last1=Saffe | first1=C. | last2=Gómez | first2=M. | last3=Pintado | first3=O. | last4=González | first4=E. | title=Spectroscopic metallicities of Vega-like stars | journal=Astronomy and Astrophysics | volume=490 | issue=1 | pages=297–305 |date=October 2008 | doi=10.1051/0004-6361:200810260 | bibcode=2008A&A...490..297S | postscript=. |arxiv = 0805.3936 | s2cid=15059920 }}</ref>
<ref name=simbad>{{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=. }}</ref>
<ref name=ibvs4659_1>{{citation | display-authors=1 | last1=Kazarovets | first1=E. V. | last2=Samus | first2=N. N. | last3=Durlevich | first3=O. V. | last4=Frolov | first4=M. S. | last5=Antipin | first5=S. V. | last6=Kireeva | first6=N. N. | last7=Pastukhova | first7=E. N. | title=The 74th Special Name-list of Variable Stars | journal=Information Bulletin on Variable Stars | volume=4659 | page=1 |date=January 1999 | bibcode=1999IBVS.4659....1K | postscript=. }}</ref>
<ref name=csiro>{{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 }}</ref>
<ref name=gcvs>{{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=. }}</ref>
}}
==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}}
Category:B-type main-sequence stars Category:Be stars Category:Gamma Cassiopeiae variable stars Category:Apus Apodis, Epsilon Category:Durchmusterung objects 5336 124771 070248 Apodis, 09 Category:Population I stars