HD 180902 b

HD 180902 b
Discovery
Discovered by	Johnson et al.
Discovery site	Keck Observatory
Discovery date	2010
Detection method	Doppler spectroscopy
Orbital characteristics
Semi-major axis	1.40±0.11 AU
Eccentricity	0.107±0.022
Orbital period (sidereal)	510.9±1.5 d
Time of perihelion	2455055±17 JD
Argument of perihelion	181±12 º
Semi-amplitude	34.25±0.84 m/s
Star	HD 180902
Physical characteristics
Mean radius	1.221 RJ
Mass	≥1.685±0.041 MJ

HD 180902 b is an extrasolar planet orbiting the K-type star HD 180902 approximately 342 light years away^[3] in the constellation Sagittarius.^[1]

Discovery

HD 180902 b, along with other planets, was discovered in 2010 by scientists at the Keck Observatory. These planets were discovered via doppler spectroscopy, which is detecting exoplanets using the star's wobble.

Properties

Orbit

HD 180902 b takes 510 days to orbit its parent star, which is longer than Earth's orbital period, which is 365 days. It orbits at a distance similar to Earth from the sun. HD 180902 orbits with mild eccentricity.

Characteristics

HD 180902 b has a minimum mass of 1.685 times the mass of Jupiter, but since its inclination is not known, the true mass of the planet cannot be detected. According to a theoretical search by the observatory, it may have a radius that is 22.1% larger than Jupiter.

Size comparison
Jupiter	HD 180902 b

References

^ ^a ^b Johnson, John Asher; et al. (2010). "Retired a Stars and Their Companions. IV. Seven Jovian Exoplanets from Keck Observatory". Publications of the Astronomical Society of the Pacific. 122 (892): 701–711. arXiv:1003.3445. Bibcode:2010PASP..122..701J. doi:10.1086/653809.
^ ^a ^b Luhn, Jacob K.; et al. (2019). "Retired A Stars and Their Companions. VIII. 15 New Planetary Signals around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts". The Astronomical Journal. 157 (4). 149. arXiv:1811.03043. Bibcode:2019AJ....157..149L. doi:10.3847/1538-3881/aaf5d0. S2CID 102486961.
^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.

External links

"HD 180902 b". Extrasolar Planets Encyclopaedia. 1995.

[Johnson2010-1] Johnson, John Asher; et al. (2010). "Retired a Stars and Their Companions. IV. Seven Jovian Exoplanets from Keck Observatory". Publications of the Astronomical Society of the Pacific. 122 (892): 701–711. arXiv:1003.3445. Bibcode:2010PASP..122..701J. doi:10.1086/653809.

[Luhn2019-2] Luhn, Jacob K.; et al. (2019). "Retired A Stars and Their Companions. VIII. 15 New Planetary Signals around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts". The Astronomical Journal. 157 (4). 149. arXiv:1811.03043. Bibcode:2019AJ....157..149L. doi:10.3847/1538-3881/aaf5d0. S2CID 102486961.

[Gaia_DR2-3] Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.

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