Giant star in the constellation Indus with one exoplanet
HIP 107773 is a star located 344 light years from Earth in the southern constellation Indus .[ 2] [ note 1] It is classified as a horizontal branch K-type giant star,[ 2] [ 3] having a spectral type K0III[ 1] and a radius of 11.6 R ☉ .[ 5] With an apparent magnitude of 5.6, the star can be faintly seen with the naked eye .[ 1] It has an exoplanet , HIP 107773 b, a gas giant orbiting it at a distance of 0.72 astronomical units (108,000,000 km),[ 6] about the same distance from Venus to the Sun .[ a]
Characteristics
HIP 107773 is a giant star , having a spectral type K0III,[ 1] 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.[ 3] [ 2] HIP 107773 has a radius equivalent to 11.6 solar radii , and a mass equivalent to about 2.4 solar masses .[ 3] It is cooler than the Sun, having an effective temperature of 4,945 K (4,672 °C).[ 3] [ b] Given the mass and the evolutionary stage of the star, its age is estimated to be at least about one billion years.[ 2]
Planetary system
HIP 107773 has an exoplanet , HIP 107773 b, discovered in 2015 using the radial velocity method .[ 6] [ 3] The planet is classified as a gas giant , having a minimum mass of 2 M J [ 3] and an estimated radius of 1.19 R J .[ 6] It orbits its star at a distance of 0.72 astronomical units (108,000,000 km), about the same distance as Venus is from the Sun ,[ a] and completes one orbit every 144 days (0.39 years).[ 3] Its orbit is almost circular, with an eccentricity of just 0.09.[ 3]
With a mass of 2.4 M ☉ , the star HIP 107773 is one of the most massive stars with a close-in planet.[ 3] [ 9]
See also
Notes and references
^ a b c d e f g h i j "HIP 107773" . SIMBAD . Retrieved January 21, 2024 .
^ a b c d e f g Ginski, C.; Mugrauer, M.; Adam, C.; Vogt, N.; Holstein, R. G. van (2021-05-01). "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" . Astronomy & Astrophysics . 649 : A156. arXiv :2009.10363 . doi :10.1051/0004-6361/202038964 . ISSN 0004-6361 .
^ a b c d e f g h i j k l Jones, M. I.; Jenkins, J. S.; Rojo, P.; Olivares, F.; Melo, C. H. F. (2015-08-01). "Giant planets around two intermediate-mass evolved stars and confirmation of the planetary nature of HIP 67851c" . Astronomy & Astrophysics . 580 : A14. arXiv :1505.06718 . doi :10.1051/0004-6361/201525853 . ISSN 0004-6361 .
^ a b "HIP-107773 (Star)" . In-The-Sky.org . Retrieved January 21, 2024 .
^ a b c "HIP 107773 Overview" . NASA Exoplanet Archive . Retrieved January 21, 2024 .
^ a b c d "HIP 107773b" . Exoplanet Exploration: Planets Beyound Our Solar System . Retrieved January 21, 2024 .
^ "Venus Fact Sheet" . nssdc.gsfc.nasa.gov . Retrieved January 21, 2024 .
^ "Sun Fact Sheet" . nssdc.gsfc.nasa.gov . Retrieved January 21, 2024 .
^ "HIP 107773 b" . Open Exoplanet Catalogue . Retrieved January 21, 2024 .
^ a b The distance from Venus to the Sun is 0.723 AU.[ 7]
^ For comparison, the effective temperature of the Sun is 5,772 K (5,499 °C).[ 8]
^ a b Obtained with a right ascension of 21h 50m 0.12s and a declination of −64° 42′ 45.1″[ 1] on this website .