HD 4391

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HD 4391
Observation data
Epoch J2000      Equinox J2000
Constellation Phoenix
Right ascension 00h 45m 45.5930s[1]
Declination –47° 33′ 07.1438″[1]
Apparent magnitude (V) 5.80[2]
Spectral type G3V[3]
B−V color index +0.64[2]
Radial velocity (Rv) –11.4[4] km/s
Proper motion (μ) RA: 183.99[1] mas/yr
Dec.: 78.81[1] mas/yr
Parallax (π) 65.97 ± 0.39[1] mas
Distance 49.4 ± 0.3 ly
(15.16 ± 0.09 pc)
Mass 1.22 ± 0.04[5] M
Surface gravity (log g) 4.85[5] cgs
Temperature 5,955[5] K
Metallicity [Fe/H] 0.01[5] dex
Rotation 12 days[6]
Rotational velocity (v sin i) 3.5[3] km/s
Age 1.2[6] Gyr
Other designations
CD-48 176, HD 4391, GJ 1021, HIP 3583, HR 209, SAO 215232.[7]

HD 4391 is a triple star system[8] in the constellation Phoenix that is located at a distance of 48.7 light years from the Sun. The primary has a stellar classification of G3V, which is a G-type main sequence star. The physical properties of this star are similar to the Sun, making it a solar analog. However, it is believed to have 22% greater mass than the Sun and is only 1.2 billion years old.[5] The spectrum for this star displays an abnormally low level of beryllium, which may be the result of some form of mixing process.[6]

No planet has been detected in orbit around this star,[5] nor does it emit a statistically significant excess of infrared radiation that might indicate a debris disk.[9] However, it has two companions that share a common proper motion through space with HD 4391, effectively making it a triple star system. The first, a red dwarf of type M4, lies at an angular separation of 17″ from the primary. The second is a type M5 star at a separation of 49″.[8]


  1. ^ a b c d e van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. 
  2. ^ a b Johnson, H. L. et al. (1966). "UBVRIJKL photometry of the bright stars.". Communications of the Lunar and Planetary Laboratory 4: 99. Bibcode:1966CoLPL...4...99J. 
  3. ^ a b Torres, C. A. O. et al. (December 2006). "Search for associations containing young stars (SACY). I. Sample and searching method". Astronomy and Astrophysics, 460 (3): 695–708. arXiv:astro-ph/0609258. Bibcode:2006A&A...460..695T. doi:10.1051/0004-6361:20065602. 
  4. ^ Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". In Alan Henry Batten and John Frederick Heard. Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: Academic Press, London. p. 57. Bibcode:1967IAUS...30...57E. 
  5. ^ a b c d e f Santos, N. C. et al. (July 2001). "The metal-rich nature of stars with planets". Astronomy and Astrophysics 373: 1019–1031. arXiv:astro-ph/0105216. Bibcode:2001A&A...373.1019S. doi:10.1051/0004-6361:20010648. 
  6. ^ a b c Santos, N. C. et al. (October 2004). "Beryllium anomalies in solar-type field stars". Astronomy and Astrophysics 425: 1013–1027. arXiv:astro-ph/0408109. Bibcode:2004A&A...425.1013S. doi:10.1051/0004-6361:20040510. 
  7. ^ "HD 4391 -- Pre-main sequence Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-07-13. 
  8. ^ a b Raghavan, Deepak et al. (September 2010). "A Survey of Stellar Families: Multiplicity of Solar-type Stars". The Astrophysical Journal Supplement 190 (1): 1–42. arXiv:1007.0414. Bibcode:2010ApJS..190....1R. doi:10.1088/0067-0049/190/1/1. 
  9. ^ Beichman, C. A. et al. (December 2006). "New Debris Disks around Nearby Main-Sequence Stars: Impact on the Direct Detection of Planets". The Astrophysical Journal 652 (2): 1674–1693. arXiv:astro-ph/0611682. Bibcode:2006ApJ...652.1674B. doi:10.1086/508449.