HIP 107773

{{Short description|Giant star in the constellation Indus with one exoplanet}}

{{Starbox image

|image={{Location mark

|image=Indus constellation map.svg|alt=|float=center|width=220

|label=|position=right

|mark=Red circle.svg|mark_width=10

|x=410|y=914

}}|caption=Location of HIP 107773 in Indus (circled)}}

{{Starbox observe

|epoch=J2000|equinox=J2000|constell=Indus{{cite constellation|HIP 107773}}|ra={{RA|21|50|0.12}}|dec={{DEC|-64|42|45.1}}|appmag_v=5.6}}

{{Starbox character

|type=Horizontal branch|class=K0III|b-v=0.99{{Cite web |title=HIP-107773 (Star) |url=https://in-the-sky.org/data/object.php?id=TYC9119-2234-1 |access-date=January 21, 2024 |website=In-The-Sky.org}}}}

{{Starbox astrometry

|dist_pc={{val|105.5|0.8}}|dist_ly={{val|343.9|2.6}}|prop_mo_dec={{val|-37.4432|0.0893}}|prop_mo_ra={{val|-0.7032|0.0807}}|parallax=9.5919|parallax_footnote=|dist_footnote=|pm_footnote=|radial_v={{val|-0.1701|0.1237}}|absmag_v=0.54}}

{{Starbox detail

|source=|mass={{val|2.42|0.27}}|radius={{val|11.6|1.4}}|luminosity={{val|74.13|1.12|1.15}}|temperature={{val|4945|100}}|age_gyr=>1|gravity={{val|2.6|0.2}}}}

{{Starbox catalog

| names = 2MASS J21500013-6442451, FK5 3742, HD 207229, HR 8331, IRAS 21461-6456, PPM 365403, SAO 255080, TIC 406320735, TYC 9119-2234-1

}}

{{Starbox reference

|Simbad=HD+207229}}

HIP 107773 is a star located 344 light years from Earth in the southern constellation Indus.{{Cite journal |last1=Ginski |first1=C. |last2=Mugrauer |first2=M. |last3=Adam |first3=C. |last4=Vogt |first4=N. |last5=Holstein |first5=R. G. van |date=2021-05-01 |title=How many suns are in the sky? A SPHERE multiplicity survey of exoplanet host stars - I. Four new close stellar companions including a white dwarf |url=https://www.aanda.org/articles/aa/abs/2021/05/aa38964-20/aa38964-20.html |journal=Astronomy & Astrophysics |language=en |volume=649 |pages=A156 |doi=10.1051/0004-6361/202038964 |issn=0004-6361|arxiv=2009.10363 }} It is classified as a horizontal branch K-type giant star, having a spectral type K0III and a radius of 11.6 {{Solar radius|link=y}}.{{Cite web |title=HIP 107773 Overview |url=https://exoplanetarchive.ipac.caltech.edu/overview/HIP%20107773 |access-date=January 21, 2024 |website=NASA Exoplanet Archive}} With an apparent magnitude of 5.6, the star can be faintly seen with the naked eye.{{Cite web |title=HIP 107773 |url=https://simbad.cds.unistra.fr/mobile/object.html?object_name=HIP+107773 |access-date=January 21, 2024 |website=SIMBAD}} It has an exoplanet, HIP 107773 b, a gas giant orbiting it at a distance of {{convert|0.72|AU|km|lk=in}},{{Cite web |title=HIP 107773b |url=https://exoplanets.nasa.gov/exoplanet-catalog/7124/hip-107773-b/ |access-date=January 21, 2024 |website=Exoplanet Exploration: Planets Beyound Our Solar System}} about the same distance from Venus to the Sun.{{Efn|1=The distance from Venus to the Sun is 0.723 AU.{{Cite web |title=Venus Fact Sheet |url=https://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html |access-date=January 21, 2024 |website=nssdc.gsfc.nasa.gov}}|name=Venus}}

Characteristics

HIP 107773 is a giant star, having a spectral type K0III, where K0 means it is a K-type star and III (luminosity class) means it is a giant star. The star is in the horizontal branch phase of evolution. HIP 107773 has a radius equivalent to 11.6 solar radii, and a mass equivalent to about 2.4 solar masses. It is cooler than the Sun, having an effective temperature of {{convert|4945|K|C|lk=in}}.{{Efn|For comparison, the effective temperature of the Sun is {{convert|5772|K|C}}.{{Cite web |title=Sun Fact Sheet |url=https://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html |access-date=January 21, 2024 |website=nssdc.gsfc.nasa.gov}} |name=Effective temperature of the Sun}} Given the mass and the evolutionary stage of the star, its age is estimated to be at least about one billion years.

Planetary system

HIP 107773 has an exoplanet, HIP 107773 b, discovered in 2015 using the radial velocity method.{{Cite journal |last1=Jones |first1=M. I. |last2=Jenkins |first2=J. S. |last3=Rojo |first3=P. |last4=Olivares |first4=F. |last5=Melo |first5=C. H. F. |date=2015-08-01 |title=Giant planets around two intermediate-mass evolved stars and confirmation of the planetary nature of HIP 67851c |url=https://www.aanda.org/articles/aa/abs/2015/08/aa25853-15/aa25853-15.html |journal=Astronomy & Astrophysics |language=en |volume=580 |pages=A14 |doi=10.1051/0004-6361/201525853 |issn=0004-6361|arxiv=1505.06718 }} The planet is classified as a gas giant, having a minimum mass of 2 {{Jupiter mass|link=y}} and an estimated radius of 1.19 {{Jupiter radius|link=y}}. It orbits its star at a distance of {{Convert|0.72|AU|km|lk=in}}, about the same distance as Venus is from the Sun,{{Efn|name=Venus}} and completes one orbit every {{Convert|144|day|year|abbr=off}}. Its orbit is almost circular, with an eccentricity of just 0.09.

With a mass of {{Val|2.4|ul=Solar mass}}, the star HIP 107773 is one of the most massive stars with a close-in planet.{{Cite web |title=HIP 107773 b |url=https://www.openexoplanetcatalogue.com/planet/HIP%20107773%20b/ |access-date=January 21, 2024 |website=Open Exoplanet Catalogue}}

{{OrbitboxPlanet begin

|table_ref=}}

{{OrbitboxPlanet

| exoplanet = b

| mass = {{val|1.98|0.21|p=≥}}

| period = {{val|144.3|0.5}}

| semimajor ={{val|0.72|0.03}}

| eccentricity ={{val|0.09|0.06}}

| inclination =

|radius=1.19 (estimate)}}