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]
Database references

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:0708.1752Freely accessible. 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/0609258Freely accessible. 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; 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/0105216Freely accessible. 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/0408109Freely accessible. 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:1007.0414Freely accessible. 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/0611682Freely accessible. Bibcode:2006ApJ...652.1674B. doi:10.1086/508449.