HD 4208

HD 4208 is a star in the southern constellation of Sculptor. It has a yellow hue with an apparent visual magnitude of 7.78,[2] making it too dim to be visible to the naked eye. But with binoculars or small telescope it should be an easy target. This object is located at a distance of 111.6 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +57 km/s.[2]

HD 4208
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Sculptor
Right ascension  00h 44m 26.6507s[1]
Declination –26° 30′ 56.4582″[1]
Apparent magnitude (V) 7.78[2]
Characteristics
Spectral type G7V Fe-1 CH-0.5[3]
B−V color index 0.664±0.004[2]
Astrometry
Radial velocity (Rv)+56.77±0.09[2] km/s
Proper motion (μ) RA: 313.484±0.064[1] mas/yr
Dec.: 149.500±0.047[1] mas/yr
Parallax (π)29.2163 ± 0.0577[1] mas
Distance111.6 ± 0.2 ly
(34.23 ± 0.07 pc)
Absolute magnitude (MV)5.23[2]
Details[4]
Mass0.86±0.02 M☉
Radius0.86±0.01 R☉
Luminosity0.71±0.004 L☉
Surface gravity (log g)4.5±0.03 cgs
Temperature5,717±33 K
Metallicity [Fe/H]−0.23[5] dex
Rotational velocity (v sin i)4.4[6] km/s
Age6.6±2.1 Gyr
Other designations
Cocibolca, BD−27°223, GJ 9024, HD 4208, HIP 3479, SAO 166526, LTT 410[7]
Database references
SIMBADdata
ARICNSdata
Extrasolar Planets
Encyclopaedia		data

The star HD 4208 is named Cocibolca. The name was selected in the NameExoWorlds campaign by Nicaragua, during the 100th anniversary of the IAU. Cocibolca is the Nahuatl name for the Lake Nicaragua.[8][9]

This is a G-type main-sequence star with a stellar classification of G7V Fe-1 CH-0.5,[3] where the suffix notation indicates underabundances of iron and carbyne in the spectrum. It is roughly 6.6[4] billion years old and is spinning with a projected rotational velocity of 4.4 km/s.[6] The star has 86% of the Sun's mass and radius, and is radiating 71% of the Sun's luminosity from its photosphere at an effective temperature of 5,717 K.[4]

In 2001, a planet was discovered orbiting the star by means of the radial velocity method.[10] This body is orbiting 1.65 AU from the host star with a period of 2.27 years and a low eccentricity of 0.05.[11] The position of this planet near the star's habitable zone means that it will have a strong gravitational perturbation effect on any potential Earth-mass planet that may be orbiting within this region.[12]

The HD 4208 planetary system[11]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b > 0.804±0.073 MJ 1.650±0.096 828.0±8.1 0.052±0.040 — —

See also

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. 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.
  3. Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637.
  4. 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. Luck, R. Earle (March 2018), "Abundances in the Local Region. III. Southern F, G, and K Dwarfs", The Astronomical Journal, 155 (3): 31, Bibcode:2018AJ....155..111L, doi:10.3847/1538-3881/aaa9b5, 111.
  6. Luck, R. Earle (January 2017), "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants", The Astronomical Journal, 153 (1): 19, arXiv:1611.02897, Bibcode:2017AJ....153...21L, doi:10.3847/1538-3881/153/1/21, 21.
  7. "HD 4208". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-05.
  8. "Approved names". NameExoworlds. Retrieved 2020-01-02.
  9. "International Astronomical Union | IAU". www.iau.org. Retrieved 2020-01-02.
  10. Vogt, Steven S.; et al. (2002). "Ten Low-Mass Companions from the Keck Precision Velocity Survey". The Astrophysical Journal. 568 (1): 352–362. arXiv:astro-ph/0110378. Bibcode:2002ApJ...568..352V. doi:10.1086/338768.
  11. 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.
  12. Hinse, T. C.; et al. (September 2008). "Dynamics and stability of telluric planets within the habitable zone of extrasolar planetary systems. Numerical simulations of test particles within the HD 4208 and HD 70642 systems". Astronomy and Astrophysics. 488 (3): 1133–1147. Bibcode:2008A&A...488.1133H. doi:10.1051/0004-6361:200809822.

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