HD 187085

HD 187085 is a yellow–hued star in the southern constellation of Sagittarius. It is too faint to be visible to the naked eye, having an apparent visual magnitude of +7.225.^[2] The star is located at a distance of approximately 1,010 light years from the Sun based on parallax,^[1] and is drifting further away with a radial velocity of +18 km/s.^[4]

HD 187085

Observation data Epoch J2000      Equinox J2000
Constellation	Sagittarius
Right ascension	19h 49m 33.9667s[1]
Declination	−37° 46′ 49.981″[1]
Apparent magnitude (V)	+7.225[2]
Characteristics
Spectral type	G0V[3]
B−V color index	0.622±0.007[2]
Astrometry
Radial velocity (Rv)	+17.70±0.59[4] km/s
Proper motion (μ)	RA: −2.853±0.344[1] mas/yr Dec.: +8.514±0.363[1] mas/yr
Parallax (π)	3.2263 ± 0.1847 mas[1]
Distance	1,010 ± 60 ly (310 ± 20 pc)
Absolute magnitude (MV)	4.00[4]
Details[2]
Mass	1.189±0.023 M☉
Radius	1.270±0.066 R☉
Luminosity	2.298+0.007 −0.006[1] L☉
Surface gravity (log g)	4.279±0.041 cgs
Temperature	6,117±27 K
Metallicity [Fe/H]	+0.12±0.04 dex
Rotation	~21 days
Age	2.747±0.838 Myr
Other designations
CD–38°13701, GC 27415, HD 187085, HIP 97546, SAO 211579[5]
Database references
SIMBAD	data

This is an ordinary G-type main-sequence star with a stellar classification of G0V,^[3] which means it is generating energy through core hydrogen fusion. It is younger than the Sun with an estimated age of 2.7 billion years and is spinning with a leisurely rotation period of around 21 days. The star is 27% larger and 19% more massive than the Sun.^[2] It is radiating 2.3^[1] times the luminosity of the Sun from its photosphere at an effective temperature of 6,117 K.^[2]

In 2006, an extrasolar planet was announced orbiting HD 187085, with a minimum mass slightly below that of the planet Jupiter. It is orbiting the host star with a period of around 2.8 years.^[6] The orbit overlaps the habitable zone of this star.^[7] In 2009, the presence of an infrared excess was announced, suggesting a debris disk orbits the star.^[8]

The HD 187085 planetary system^[2]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥0.836±0.011 MJ	2.100±0.032	1,019.74+21.29 −22.58	0.251+0.221 −0.191	—	—

See also

• HD 188015
• HD 20782
• List of extrasolar planets

References

1. 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.
2. Barbato, D.; et al. (August 2018), "Exploring the realm of scaled solar system analogues with HARPS", Astronomy & Astrophysics, 615: 21, arXiv:1804.08329, Bibcode:2018A&A...615A.175B, doi:10.1051/0004-6361/201832791, S2CID 119099721, A175.
3. Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
4. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
5. "HD 187085". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-09.
6. Jones, Hugh R. A.; et al. (2006), "High-eccentricity planets from the Anglo-Australian Planet Search", Monthly Notices of the Royal Astronomical Society, 369 (1): 249–256, arXiv:astro-ph/0603335, Bibcode:2006MNRAS.369..249J, doi:10.1111/j.1365-2966.2006.10298.x, S2CID 15452372.
7. Agnew, Matthew T.; et al. (November 2017), "Stable habitable zones of single Jovian planet systems", Monthly Notices of the Royal Astronomical Society, 471 (4): 4494–4507, arXiv:1706.05805, Bibcode:2017MNRAS.471.4494A, doi:10.1093/mnras/stx1449, S2CID 119227856.
8. Kóspál, Ágnes; et al. (August 2009), "On the Relationship Between Debris Disks and Planets", The Astrophysical Journal Letters, 700 (2): L73 – L77, arXiv:0907.0028, Bibcode:2009ApJ...700L..73K, doi:10.1088/0004-637X/700/2/L73, S2CID 16636256.

External links

• "Notes for star HD 187085". Extrasolar Planets Encyclopaedia. Archived from the original on July 2, 2007.