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HD 2039

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HD 2039
Phoenix constellation map.png
The Phoenix constellation, where HD 2039 is located
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Phoenix
Right ascension  00h 24m 20.2782s[1]
Declination −56° 39′ 00.1818″[1]
Apparent magnitude (V) 9.00[2]
Spectral type G2/G3 IV-V[2]
B−V color index 0.66[2]
Radial velocity (Rv)8.4 ± 0.2[2] km/s
Proper motion (μ) RA: 78.454±0.042[1] mas/yr
Dec.: 14.512±0.040[1] mas/yr
Parallax (π)11.6408 ± 0.0276[1] mas
Distance280.2 ± 0.7 ly
(85.9 ± 0.2 pc)
Absolute magnitude (MV)3.96 ± 0.21 [3]
Mass1.2 ± 0.03[4] M
Radius1.4 ± 0.04[4] R
Luminosity2.18 ± 0.02[4] L
Surface gravity (log g)4.22 ± 0.03[4] cgs
Temperature5935 ± 64[4] K
Metallicity [Fe/H]0.30 ± 0.03[5] dex
Age4.4 ± 0.8[4] Gyr
Other designations
CD−57° 71, HIP 1931, SAO 232025[2]
Database references

HD 2039 is a yellow dwarf or yellow subgiant star in the constellation Phoenix. The star is not visible to the naked eye, and lies 280 light years away from the Sun. HD 2039 is a relatively stable star, and an exoplanet at least three times the mass of the planet Jupiter has been discovered in its orbit; this exoplanet, known as HD 2039 b, was the 100th exoplanet to be discovered.[6]


The designation HD 2039 from the Henry Draper Catalogue. The catalogue, which was published between 1918 and 1924, was based on the work of Annie Jump Cannon and her team between 1911 and 1915.[7][8] HD 2039 does not have a common, colloquial name that is characteristic of stars like Sirius, Procyon, and Aldebaran.


HD 2039 is a stable[9] G-type star, meaning it shines with white light that can be seen in the Sun. In terms of mass, the star exhibits almost identical properties. HD 2039 exhibits a radius approximately 40 percent larger than the Sun's.[4] The star is slightly hotter than the Sun; while HD 2039 has a temperature of 5935 K,[4] the Sun's surface temperature lies nearly 200 kelvins lower at 5778 K.[10] HD 2039 is unusually metal-rich, which has attracted the attention of astrophysicists.[9]

Distance and visibility[edit]

The star's magnitude as observed from Earth is 9; this signifies that the body is not visible with the naked eye, but can be seen with a telescope.[11] HD 2039 lies roughly 280 light years from the Sun,[1] which is about as far from the Sun as the second brightest star in the night sky, Canopus.[12]

Planetary system[edit]

In 2002, a planet was found by the Anglo-Australian Planet Search team to be orbiting the star in a very eccentric orbit.[9] It has a minimum mass more than six times that of Jupiter and has an orbital period of over three years. The planet orbits its star at a distance of approximately two AU away; the planet Earth, in comparison, orbits at a distance of one AU away from the Sun.[13] HD 2039 b's discovery was reported quietly; no press release was provided by the observatory that discovered the star's planet, and no formal announcement of the planet's existence was made.[6] The entity was the 100th exoplanet to have been verified by the scientific community.[6]

The HD 2039 planetary system[14]
(in order from star)
Mass Semimajor axis
Orbital period
Eccentricity Inclination Radius
b >6.11 ± 0.82 MJ 2.23 ± 0.13 1120 ± 23 0.715 ± 0.046

See also[edit]


  1. ^ a b c d e f 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. ^ a b c d e "HD 2039". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2008-12-06.
  3. ^ Holmberg; et al. (2009). "HD 2039". Geneva-Copenhagen Survey of Solar neighbourhood III. Retrieved 2010-12-04.
  4. ^ a b c d e f g h Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951.
  5. ^ Ghezzi, L.; et al. (September 2010), "Stellar Parameters and Metallicities of Stars Hosting Jovian and Neptunian Mass Planets: A Possible Dependence of Planetary Mass on Metallicity", The Astrophysical Journal, 720 (2): 1290–1302, arXiv:1007.2681, Bibcode:2010ApJ...720.1290G, doi:10.1088/0004-637X/720/2/1290
  6. ^ a b c Britt, Robert (July 2, 2002). "Planet Tally Soars to Near 100, Astronomers Scramble to Keep Track". Archived from the original on 9 October 2002. Retrieved 29 November 2008.
  7. ^ pp. 214–215 in The Henry Draper Memorial, Annie J. Cannon, Journal of the Royal Astronomical Society of Canada 9, #5 (May–June 1915), pp. 203–215, Bibcode1915JRASC...9..203C.
  8. ^ The Henry Draper Catalogue, Annie J. Cannon and Edward C. Pickering, Annals of Harvard College Observatory;
    hours 0 to 3, 91 (1918), Bibcode1918AnHar..91....1C;
    hours 4 to 6, 92 (1918), Bibcode1918AnHar..92....1C;
    hours 7 to 8, 93 (1919), Bibcode1919AnHar..93....1C;
    hours 9 to 11, 94 (1919), Bibcode1919AnHar..94....1C;
    hours 12 to 14, 95 (1920), Bibcode1920AnHar..95....1C;
    hours 15 to 16, 96 (1921), Bibcode1921AnHar..96....1C;
    hours 17 to 18, 97 (1922), Bibcode1922AnHar..97....1C;
    hours 19 to 20, 98 (1923), Bibcode1923AnHar..98....1C;
    hours 21 to 23, 99 (1924), Bibcode1924AnHar..99....1C.
  9. ^ a b c Tinney, C. G.; et al. (2003). "Four New Planets Orbiting Metal-enriched Stars". The Astrophysical Journal. 587 (1): 423–428. arXiv:astro-ph/0207128. Bibcode:2003ApJ...587..423T. doi:10.1086/368068.
  10. ^ "Sun Factsheet". Planetary Fact Sheet set. National Aeronautics and Space Administration. 2004. Retrieved 13 January 2009.
  11. ^ "Stellar Magnitudes". Astrophysics 162 Unit. University of Tennessee. 2008. Retrieved 20 November 2008.
  12. ^ Rao, Joe (February 17, 2005). "Great Star of the South". Retrieved 29 November 2008.
  13. ^ "Astronomical unit". Glossary. National Aeronautics and Space Administration. 2008. Retrieved 29 November 2008.
  14. ^ Butler, R. P.; et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal. 646 (1): 505–522. arXiv:astro-ph/0607493. Bibcode:2006ApJ...646..505B. doi:10.1086/504701.

External links[edit]

Coordinates: Sky map 00h 24m 20.2778s, −56° 39′ 00.171″