{{short description|Star in the constellation Capricornus}} {{Starbox begin | name = Omega Capricorni }} {{Starbox image | image= {{Location mark |image=Capricornus constellation map.svg|alt=|float=center|width=280 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=ω Cap |x=556|y=779 }} | caption = Location of ω Capricorni (circled) }}{{Starbox observe | epoch = J2000.0 | equinox = J2000.0 (ICRS) | constell = Capricornus | ra = {{RA|20|51|49.291}}<ref name=GaiaDR3/> | dec = {{DEC|−26|55|08.89}}<ref name=GaiaDR3/> | appmag_v = +4.11<ref name=Nicolet1978/> }} {{Starbox character | type = horizontal branch<ref name=stock2018/> | class = K4&nbsp;III<ref name=houk1979/> | b-v = +1.64<ref name=Nicolet1978/> | u-b = +1.93<ref name=Nicolet1978/> | r-i = | variable = Suspected<ref name=AAVSO/> }} {{Starbox astrometry | radial_v = {{Val|+9.1|1.4}}<ref name=Gontcharov2006/> | prop_mo_ra = −9.016 | prop_mo_dec = −2.048 | pm_footnote = <ref name=GaiaDR3/> | parallax = 5.8975 | p_error = 0.3064 | parallax_footnote = <ref name=GaiaDR3/> | absmag_v = −2.7<ref name=Mennessier1997/> }} {{Starbox detail | source = | mass = {{Val|7.60|0.40|0.04}}<ref name=GaiaDR3/> | radius = {{Val|93.2|4.9|3.8}}<ref name=GaiaDR3/> | luminosity = {{Val|3194|344|278|fmt=commas}}<ref name=GaiaDR3/> | temperature = {{Val|4474|79|13|fmt=commas}}<ref name=GaiaDR3/> | gravity = {{Val|0.84|0.15|0.02}}<ref name=GaiaDR3/> | metal_fe = −0.24<ref name=McWilliam1990/> | rotational_velocity = 4.68<ref name=Hekker2007/> | age_myr = {{Val|48.1|8.3}}<ref name=Tetzlaff2011/> }} {{Starbox catalog | names = {{odlist | B=ω&nbsp;Cap | F=18&nbsp;Cap | CD=−27°15082 | FK5=1546 | HD=198542 | HIP=102978 | HR=7980 | SAO=189781 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = ome+Cap }} {{Starbox end}}

'''Omega Capricorni''', is an orange-hued star in the southern constellation Capricornus, near the southern constellation border with Microscopium. Its name is a Bayer designation that is Latinized from ω Capricorni, and abbreviated Omega Cap or ω Cap. This star is faintly visible to the naked eye, having an apparent visual magnitude of +4.11.<ref name=Nicolet1978/> Based upon an annual parallax shift of {{Val|5.9|ul=mas}} as seen from the Earth,<ref name=GaiaDR3/> it is located approximately {{convert|550|ly|pc|abbr=out|lk=on}} distant from the Sun. It is a candidate member of the Ursa Major Moving Group<ref name=Chupina2006/> and has a relatively high peculiar velocity of {{Val|25.7|1.9|u=km/s}}, making it is a possible runaway star.<ref name=Tetzlaff2011/>

In Chinese, {{lang|zh|天田}} ({{lang|zh-Latn|Tiān Tián}}), meaning ''Celestial Farmland'', refers to an asterism consisting of ω Capricorni, 3 Piscis Austrini, 24 Capricorni and ψ Capricorni.<ref>{{in lang|zh}} ''中國星座神話'', written by 陳久金. Published by 台灣書房出版有限公司, 2005, {{ISBN|978-986-7332-25-7}}.</ref> Consequently, the Chinese name for ω Capricorni itself is {{lang|zh|天田二}} ({{lang|zh-Latn|Tiān Tián èr}}, {{langx|en|the First Star of Celestial Farmland}}.)<ref>{{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0607/ap060703.html AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 3 日] {{Webarchive|url=https://web.archive.org/web/20110521232833/http://aeea.nmns.edu.tw/2006/0607/ap060703.html |date=2011-05-21 }}</ref>

This is an evolved K-type giant star with a stellar classification of K4&nbsp;III,<ref name=houk1979/> and is a suspected variable.<ref name=AAVSO/> With the supply of hydrogen at its core exhausted, the star has expanded to about 93<ref name=GaiaDR3/> times the radius of the Sun. It is 48<ref name=Tetzlaff2011/>&nbsp;million years old with 7.6 times the mass of the Sun. Omega Capricorni is radiating 3,194 times the luminosity of the Sun from its bloated photosphere at an effective temperature of 4,474&nbsp;K.<ref name=GaiaDR3/> It is a barium star,<ref name=Mennessier1997/> showing an overabundance of the s-process elements. This suggests that Omega Capricorni has an orbiting white dwarf companion.<ref name=gomez1997/>

==References== <references>

<ref name=GaiaDR3>{{cite DR3 | 6801963487915169920 | mode=cs2 | access-date=2025-09-05 | postscript=. }}</ref>

<ref name=SIMBAD>{{cite simbad | title=ome Cap | mode=cs2 | access-date=2017-05-07 | postscript=. }}</ref>

<ref name=AAVSO>{{citation | title=NSV 13351 | publisher=American Association of Variable Star Observers | url=https://www.aavso.org/vsx/index.php?view=detail.top&oid=51975 | access-date=2017-05-07 | postscript=. }}</ref>

<ref name=Gontcharov2006>{{citation | last=Gontcharov | first=G. A. | title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system | journal=Astronomy Letters | postscript=. | volume=32| issue=11| pages=759–771| date=November 2006 | doi = 10.1134/S1063773706110065 | s2cid=119231169 | bibcode=2006AstL...32..759G | arxiv=1606.08053 }}</ref>

<ref name=Mennessier1997>{{citation | title=Barium stars, galactic populations and evolution. | display-authors=1 | last1=Mennessier | first1=M. O. | last2=Luri | first2=X. | last3=Figueras | first3=F. | last4=Gomez | first4=A. E. | last5=Grenier | first5=S. | last6=Torra | first6=J. | last7=North | first7=P. | journal=Astronomy and Astrophysics | volume=326 | pages=722–730 | date=October 1997 | bibcode=1997A&A...326..722M | postscript=. }}</ref>

<ref name=gomez1997>{{citation | display-authors=1 | last1=Gomez | first1=A. E. | last2=Luri | first2=X. | last3=Grenier | first3=S. | last4=Prevot | first4=L. | last5=Mennessier | first5=M. O. | last6=Figueras | first6=F. | last7=Torra | first7=J. | title=Absolute magnitudes and kinematics of barium stars | journal=Astronomy and Astrophysics | volume=319 | pages=881 | year=1997 | bibcode=1997A&A...319..881G | postscript=. }}</ref>

<ref name=McWilliam1990>{{citation | doi=10.1086/191527 | bibcode=1990ApJS...74.1075M | title=High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances | journal=The Astrophysical Journal Supplement Series | volume=74 | pages=1075 | year=1990 | postscript=. | last=McWilliam | first=Andrew | doi-access=free }}</ref>

<ref name=Chupina2006>{{citation | display-authors=1 | last1=Chupina | first1=N. V. | last2=Reva | first2=V. G. | last3=Vereshchagin | first3=S. V. | title=Kinematic structure of the corona of the Ursa Major flow found using proper motions and radial velocities of single stars | journal=Astronomy and Astrophysics | postscript=. | volume=451 | issue=3 | pages=909–916 | date=June 2006 | doi=10.1051/0004-6361:20054009 | bibcode=2006A&A...451..909C | doi-access=free }} See table 7.</ref>

<ref name=Hekker2007>{{citation | last1=Hekker | first1=S. | last2=Meléndez | first2=J. | title=Precise radial velocities of giant stars. III. Spectroscopic stellar parameters | journal=Astronomy and Astrophysics | volume=475 | issue=3 | pages=1003–1009 | date=December 2007 | doi=10.1051/0004-6361:20078233 | bibcode=2007A&A...475.1003H | arxiv=0709.1145 | s2cid=10436552 | postscript=. }}</ref>

<ref name=Tetzlaff2011>{{citation | display-authors=1 | 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 | arxiv=1007.4883 | s2cid=118629873 | postscript=. }}</ref>

<ref name=houk1979>{{citation | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=3 | last=Houk | first=Nancy | postscript=. | publication-place=Ann Arbor, Michigan | publisher=Dept. of Astronomy, University of Michigan | date=1979 | bibcode=1982mcts.book.....H }}</ref>

<ref name=Nicolet1978>{{citation | last=Nicolet | first=B. | year=1978 | postscript=. | 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 }}</ref>

<ref name=stock2018>{{cite journal |last1=Stock |first1=Stephan |last2=Reffert |first2=Sabine |last3=Quirrenbach |first3=Andreas |title=Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search |journal=Astronomy and Astrophysics |date=2018 |volume=616 |pages=A33 |doi=10.1051/0004-6361/201833111 |arxiv=1805.04094 |bibcode=2018A&A...616A..33S }}</ref>

</references>

{{Stars of Capricornus|state=collapsed}}

<!-- Properties --> Category:K-type giants Category:Suspected variables Category:Barium stars Category:Runaway stars Category:Ursa Major moving group <!-- Identifiers/constellation --> Category:Capricornus Capricorni, Omega 7980 Category:Durchmusterung objects Capricorni, 18 198542 102978 Category:Horizontal-branch stars