HD 187123

HD 187123 is an 8th magnitude G-type main sequence star located approximately 150 light-years away in the constellation of Cygnus. Like our Sun, it is a yellow dwarf (spectral type G5V). Being at a distance of about 160 light-years it is not visible to the unaided eye. However, it should be easy target with binoculars or small telescope.

HD 187123
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cygnus
Right ascension  19h 46m 58.1123s[1]
Declination +34° 25 10.2799[1]
Apparent magnitude (V) 7.89
Characteristics
Spectral type G5V
Astrometry
Proper motion (μ) RA: 142.581±0.053[1] mas/yr
Dec.: −123.603±0.063[1] mas/yr
Parallax (π)21.7316 ± 0.0336[1] mas
Distance150.1 ± 0.2 ly
(46.02 ± 0.07 pc)
Details
Other designations
BD+34°3708, HIP 97336, LTT 15779, SAO 68845
Database references
SIMBADdata
HD 187123 has a planetary system with at least two planets in it. Artist's rendition of planets HD 187123b and c.

Planetary system

In 1998 the California and Carnegie Planet Search team, after following a suggestion by Kevin Apps, a Briton who at the time was an undergraduate student[2] found a possible planet orbiting the star.[3] There were also indications of another, more distant body orbiting the star and this claim was published in 2006.[4] This planet was confirmed in 2009.[5]

The HD 187123 planetary system[6]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b >0.5074±0.0026 MJ 0.04213±0.00034 3.0965886±0.0000043 0.0093±0.0046
c >1.818±0.035 MJ 4.417±0.054 3324±46 0.280±0.022
gollark: Run them at 1000x speed, connect them to Wikipedia, and... maths?
gollark: Just simulate a mathematician's brain on an arbitrarily powerful computer, silly.
gollark: Computers can totally prove stuff!
gollark: What about the halting problem? CHECKMATE, CALCULATORISTS!
gollark: Seems reasonable, then!

See also

  • 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. "British student shows Nasa new planet". BBC News. September 25, 1998. Retrieved December 31, 2011.
  3. Butler, R. Paul; et al. (1998). "A Planet with a 3.1 Day Period around a Solar Twin". Publications of the Astronomical Society of the Pacific. 110 (754): 1389–1393. Bibcode:1998PASP..110.1389B. CiteSeerX 10.1.1.37.5463. doi:10.1086/316287.
  4. Wright, J. T.; et al. (2007). "Four New Exoplanets and Hints of Additional Substellar Companions to Exoplanet Host Stars". The Astrophysical Journal. 657 (1): 533–545. arXiv:astro-ph/0611658. Bibcode:2007ApJ...657..533W. doi:10.1086/510553.
  5. Wright, J. T.; et al. (2009). "Ten New and Updated Multi-planet Systems, and a Survey of Exoplanetary Systems". The Astrophysical Journal. 693 (2): 1084–1099. arXiv:0812.1582. Bibcode:2009ApJ...693.1084W. doi:10.1088/0004-637X/693/2/1084.
  6. Feng, Y. Katherina; et al. (2015). "The California Planet Survey IV: A Planet Orbiting the Giant Star HD 145934 and Updates to Seven Systems with Long-period Planets". The Astrophysical Journal. 800 (1). 22. arXiv:1501.00633. Bibcode:2015ApJ...800...22F. doi:10.1088/0004-637X/800/1/22.


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