{{Short description|Star in the constellation Apus}} {{Starbox begin | name = ι Apodis }} {{Starbox image | image= {{Location mark |image=Apus constellation map.svg|alt=|float=center|width=240 |label=|position=right |mark=Red circle.svg|mark_width=8|mark_link=ι Apodis |x=244|y=364 }} |caption=Location of ι Apodis (circled) }} {{Starbox observe | epoch = J2000 | ra = {{RA|17|22|05.876}}<ref name=dr3/> | dec = {{DEC|-70|07|23.54}}<ref name=dr3/> | appmag_v = 5.41<ref name=aass34_1/> (5.90/6.46)<ref name=mnras389_2_869/> | constell = Apus }} {{Starbox character | class = {{nowrap|B9 V + B9.5 V}}<ref name=mnras389_2_869/> | b-v = −0.04<ref name=aass34_1/> | u-b = −0.23<ref name=aass34_1/> | variable = }} {{Starbox astrometry | radial_v = −4.3<ref name=gcsrv/> | prop_mo_ra = −1.881 | prop_mo_dec = −11.363 | pm_footnote = <ref name=dr3/> | parallax = 3.1948 | p_error = 0.1853 | parallax_footnote = <ref name=dr3/> | absmag_v = }} {{Starbox orbit | reference = <ref name=Docobo2013/> | period = {{Val|59.32|3.0}} | axis = {{Val|0.115|0.005}} | eccentricity = {{Val|0.172|0.050}} | inclination = {{Val|69.4|3.0}} | node = {{Val|119.6|4.0}} | periastron = <!--Periastron epoch--> | periarg = {{Val|270.5|7.0}} }} {{Starbox detail | component1 = ι Aps A | mass = {{Val|3.89|1.02}}<ref name=Docobo2013/> | radius = | luminosity = | temperature = | metal_fe = | rotational_velocity = | age_myr = | component2 = ι Aps B | mass2 = {{Val|3.45|0.90}}<ref name=Docobo2013/> }} {{Starbox catalog | names={{odlist | B=ι Apodis, Iot Aps, ι Aps | FK5=642 | HD=156190 | HIP=84979 | HR=6411 | SAO=257491 | WDS=J17221−7007 | CPD=−69 2719 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = iot+Aps }} {{Starbox end}}
'''Iota Apodis''' is a binary star<ref name=mnras389_2_869/> system in the southern circumpolar constellation of Apus. Its identifier is a Bayer designation that is Latinized from ι Apodis, and abbreviated Iot Aps or ι Aps, respectively. This system is a faint target at an apparent visual magnitude of 5.41,<ref name=aass34_1/> but still visible to the naked eye from suitably dark skies. The distance to this star can be gauged from parallax measurements, yielding an estimate of {{Convert|1,020|ly|pc|abbr=off|lk=on}} with a 6% margin of error.<ref name=dr3/> The system is drifting closer with a heliocentric radial velocity of −4.3 km/s.<ref name=gcsrv/>
The dual nature of this system was announced by W. S. Finsen in 1960, who reported an angular separation of {{val|0.104|ul=arcseconds}}.<ref name=Finsen_1960/> Their orbit has an angular separation of 0.091 arcseconds<ref name=mnras389_2_869/> with an estimated orbital period of 59.32 years and an eccentricity (ovalness) of 0.17.<ref name=Docobo2013/> Both stars are B-type main sequence stars, which indicates they shine with a blue-white hue.<ref name=csiro/> The brighter component has a stellar classification of B9 V and an apparent magnitude 5.90, while the second member is a B9.5 V star with a magnitude of 6.46. They are about 3.89 and 3.45 times as massive as the Sun, respectively.<ref name=Docobo2013/>
==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 ι Apodis, ζ Apodis, β Apodis, γ Apodis, δ Octantis, δ<sup>1</sup> Apodis, η Apodis, α Apodis and ε Apodis. Consequently, ι Apodis itself is known as {{lang|zh|異雀二}} ({{lang|zh-Latn|Yì Què èr}}, {{langx|en|the Second Star of Exotic Bird}}.)<ref>{{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>
==References== {{reflist|30em|refs=
<ref name=dr3>{{cite Gaia DR3|5810861541976948096}}</ref>
<ref name=Docobo2013>{{citation | title=Dynamical and physical properties of 22 binaries discovered by W. S. Finsen | last1=Docobo | first1=J. A. | last2=Andrade | first2=M. | journal=Monthly Notices of the Royal Astronomical Society | volume=428 | issue=1 | pages=321–339 | date=January 2013 | doi=10.1093/mnras/sts045 | bibcode=2013MNRAS.428..321D | postscript=. | doi-access=free }}</ref>
<ref name=gcsrv>{{citation | last=Wilson | first=Ralph Elmer | year=1953 | title=General Catalogue of Stellar Radial Velocities | journal=Carnegie Institute Washington D.C. Publication | publisher=Carnegie Institution of Washington | location=Washington | bibcode=1953GCRV..C......0W | postscript=. }}</ref>
<ref name=aass34_1>{{citation | last1=Nicolet | first1=B. | year=1978 | title=Photoelectric photometric Catalogue of homogeneous measurements in the UBV System | journal=Astronomy and Astrophysics Supplement Series | volume=34 | pages=1–49 | bibcode=1978A&AS...34....1N | postscript=. }}</ref>
<ref name=mnras389_2_869>{{citation | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=869–879 |date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E | postscript=. |arxiv = 0806.2878 | s2cid=14878976 }}</ref>
<ref name=SIMBAD>{{cite simbad | title=* iot Aps | accessdate=2012-07-09 | 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 |url-status=dead |archiveurl=https://web.archive.org/web/20120318151427/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html |archivedate=March 18, 2012 }}</ref>
<ref name=Finsen_1960>{{citation | postscript=. | title=New Double Stars (XVII) | last=Finsen | first=W. S. | journal=Monthly Notes of the Astronomical Society of Southern Africa | volume=19 | page=178 | year=1960 | bibcode=1960MNSSA..19..178F }}</ref>
}}
==External links== * [http://aladin.u-strasbg.fr/AladinPreview?-c=17+22+05.8760-70+07+23.549&ident=CCDM+J17221-7007AB&submit=Aladin+previewer Image Iota Apodis]
{{Stars of Apus}}
Category:B-type main-sequence stars Category:Binary stars Category:Apus Apodis, Iota 6411 Category:Durchmusterung objects 156190 084979 Apodis, 58