View source for Astronomy:Omicron Coronae Borealis

{{Short description|Star in the constellation Corona Borealis}}
{{Starbox begin 
| name = o Coronae Borealis
}} 
{{Starbox image
| image =
{{Location mark
|image=Corona Borealis constellation map.svg|alt=|float=center|width=280
|label=|position=right
|mark=Red circle.svg|mark_width=10|mark_link=o CrB
|x=738|y=523
}}
|caption=Location of o Coronae Borealis (circled)
}}
{{Starbox observe 
| epoch = J2000.0
| constell = [[Astronomy:Corona Borealis|Corona Borealis]]
| ra = {{RA|15|20|08.559}}<ref name="van Leeuwen2007"/>
| dec = {{DEC|+29|36|58.35}}<ref name="van Leeuwen2007"/>
| appmag_v = +5.53<ref name=Jennens1975/>
}}
{{Starbox character
| class = K0&nbsp;III<ref name=Anderson2012/>
| b-v = +1.009<ref name=Jennens1975/>
| u-b = +0.786<ref name=Jennens1975/>
}}
{{Starbox astrometry 
| radial_v = {{Val|−54.15|0.20}}<ref name=jofre2015/>
| prop_mo_ra = {{Val|−117.98|0.18}}<ref name="van Leeuwen2007"/> 
| prop_mo_dec = {{Val|−42.44|0.31}}<ref name="van Leeuwen2007"/> 
| parallax = 12.08 
| p_error = 0.44
| parallax_footnote = <ref name="van Leeuwen2007"/>
| absmag_v = +0.92<ref name=Anderson2012/>
}}
{{Starbox detail 
| source = <ref name=jofre2015/>
| age_gyr = {{Val|5.54|2.79}}
| metal_fe = {{Val|−0.24|0.01}}
| mass = {{Val|1.07|0.19}}
| gravity = {{Val|2.70|0.06}}
| temperature = {{Val|4812|13|fmt=commas}}
| radius = {{Val|10.13|0.40}}
| luminosity = 50.1
| rotational_velocity = {{Val|0.47|0.61}}
}}
{{Starbox catalog
}}
{{Starbox reference
| Simbad = HD+136512
| NSTED = HD+136512
| EPE = HD+136512
}}
{{Starbox end}}

'''Omicron Coronae Borealis''', [[Social:Latinisation of names|Latinized]] from o Coronae Borealis, is a [[Astronomy:Star|star]] in the northern [[Astronomy:Constellation|constellation]] of [[Astronomy:Corona Borealis|Corona Borealis]]. It is a faint star but visible to the naked eye on a dark night with an [[Astronomy:Apparent visual magnitude|apparent visual magnitude]] of +5.53.<ref name=Jennens1975/> The annual [[Astronomy:Stellar parallax|parallax shift]] of the star as seen from Earth is 12.08&nbsp;mas, which provides a distance estimate of around 270&nbsp;[[Light year|light year]]s. It is moving closer to the Sun with a [[Astronomy:Radial velocity|radial velocity]] of −54&nbsp;km/s.<ref name=jofre2015/>

Based upon the [[Spectrum|spectrum]] of this star, it has a [[Astronomy:Stellar classification|stellar classification]] of K0&nbsp;III.<ref name=Anderson2012/> This indicates this is an [[Astronomy:Stellar evolution|evolved]] [[Astronomy:K-type star|K-type]] [[Astronomy:Giant star|giant star]] that has exhausted the hydrogen at its core and has left the [[Astronomy:Main sequence|main sequence]]. This is a [[Astronomy:Red clump|red clump]] star, which means it is now generating energy through helium fusion at its [[Astronomy:Stellar core|core]]. It has 107% of the mass of the Sun and has expanded to over ten times the Sun's radius. The star is radiating 50 times the Sun's luminosity from its expanded [[Astronomy:Photosphere|photosphere]] at an [[Astronomy:Effective temperature|effective temperature]] of 4,812&nbsp;K.<ref name="Sato2012"/>
==Planetary system==
Omicron Coronae Borealis has one confirmed planet, believed to be, along with [[Astronomy:HD 100655|HD 100655 b]], one of the two least massive planets known around [[Astronomy:Red clump|red clump]] giants.<ref name="Sato2012" /> The planet was detected by measuring changes in radial velocity of the host star caused by gravitational perturbation of the orbiting object. It is orbiting with a period of 188&nbsp;days, at a semimajor axis 83% of the mean separation between the Earth and the Sun, and an [[Astronomy:Orbital eccentricity|eccentricity]] of 0.19.<ref name="Sato2012"/>

{{OrbitboxPlanet begin
| table_ref = <ref name="Sato2012"/>
| period_unit = day
}}
{{OrbitboxPlanet
| exoplanet = b
| semimajor = 0.83
| eccentricity = 0.191 ± 0.085
| period = 187.83 ± 0.54
| mass = >1.5
}} 
{{Orbitbox end}}

==References==
{{reflist|refs=

<ref name="Sato2012">{{citation
 | title=Substellar Companions to Seven Evolved Intermediate-Mass Stars
 | url=https://academic.oup.com/pasj/article/64/6/135/1422181 
 | last1=Sato | first1=Bun'ei | last2=Omiya | first2=Masashi
 | last3=Harakawa | first3=Hiroki | last4=Izumiura | first4=Hideyuki
 | last5=Kambe | first5=Eiji | last6=Takeda | first6=Yoichi
 | last7=Yoshida | first7=Michitoshi | last8=Itoh | first8=Yoichi
 | last9=Ando | first9=Hiroyasu | last10=Kokubo | first10=Eiichiro
 | last11=Ida | first11=Shigeru | display-authors=1
 | journal=Publications of the Astronomical Society of Japan
 | volume=64 | issue=6 | at=135 | year=2012
 | arxiv=1207.3141 | bibcode=2012PASJ...64..135S
 | doi=10.1093/pasj/64.6.135 | s2cid=119197073 
 | postscript=. }}</ref>

<ref name=Jennens1975>{{citation | postscript=.
 | last1=Jennens | first1=P. A. | last2=Helfer | first2=H. L.
 | title=A new photometric metal abundance and luminosity calibration for field G and K giants
 | journal=[[Organization:Monthly Notices of the Royal Astronomical Society|Monthly Notices of the Royal Astronomical Society]]
 | volume=172 | issue=3 | pages=667–679 | date=September 1975
 | bibcode=1975MNRAS.172..667J | doi=10.1093/mnras/172.3.667 | doi-access=free }}</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="van Leeuwen2007">{{citation
 | title=Validation of the new Hipparcos reduction
 | last1=van Leeuwen | first1=F. | postscript=.
 | journal=Astronomy and Astrophysics
 | volume=474 | issue=2 | pages=653–664 | year=2007
 | arxiv=0708.1752 | bibcode=2007A&A...474..653V
 | doi=10.1051/0004-6361:20078357 | s2cid=18759600 }}[http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=74803 Vizier catalog entry ]</ref>

<ref name=jofre2015>{{citation
 | title=Stellar parameters and chemical abundances of 223 evolved stars with and without planets
 | last1=Jofré | first1=E | last2=Petrucci | first2=R
 | last3=Saffe | first3=C | last4=Saker | first4=L
 | last5=de la Villarmois | first5=E. Artur | last6=Chavero | first6=C
 | last7=Gómez | first7=M | last8=Mauas | first8=P. J. D
 | journal=Astronomy & Astrophysics | postscript=.
 | volume=574 | pages=A50 | id=A50 | year=2015 | display-authors=1
 | bibcode=2015A&A...574A..50J | doi=10.1051/0004-6361/201424474 | arxiv=1410.6422| s2cid=53666931 }}</ref>

}}

{{Stars of Corona Borealis}}

{{DEFAULTSORT:Omicron Coronae Borealis}}
[[Category:K-type giants]]
[[Category:Horizontal-branch stars]]
[[Category:Suspected variables]]
[[Category:Planetary systems with one confirmed planet]]
[[Category:Bayer objects|Corona Borealis, Omicron]]
[[Category:Corona Borealis]]
[[Category:Durchmusterung objects]]
[[Category:Flamsteed objects|Coronae Borealis, 01]]
[[Category:Henry Draper Catalogue objects|136512]]
[[Category:Hipparcos objects|075049]]
[[Category:Bright Star Catalogue objects|5709]]
[[Category:2MASS objects|J15200853+2936584]]

{{Sourceattribution|Omicron Coronae Borealis}}