HD 4628

From Wikipedia, the free encyclopedia
  (Redirected from Gliese 33)
Jump to navigation Jump to search
HD 4628
Observation data
Epoch J2000      Equinox J2000
Constellation Pisces
Right ascension  00h 48m 22.98s[1]
Declination +05° 16′ 50.2″[1]
Apparent magnitude (V) 5.74[2]
Spectral type K2.5 V[3]
U−B color index +0.60[3]
B−V color index +0.89[3]
Radial velocity (Rv)−10.8[4] km/s
Proper motion (μ) RA: 757.11±0.48[1] mas/yr
Dec.: −1141.33±0.34[1] mas/yr
Parallax (π)134.14 ± 0.51[1] mas
Distance24.31 ± 0.09 ly
(7.45 ± 0.03 pc)
Absolute magnitude (MV)6.37[5]
Mass0.70±0.10[6] M
Radius0.749±0.051[7] R
Luminosity0.28[6] L
Surface gravity (log g)4.39±0.16[6] cgs
Temperature5829±41[6] K
Metallicity [Fe/H]–0.22[8] dex
Rotation38.0 days[8]
Age5.4[9] Gyr
Other designations
96 G. Piscium,[10] BD +04°123, GCTP 156.00, Gl 33, HD 4628, HIP 3765, HR 222, Lal 1299, LHS 121, LTT 10285, SAO 109471, Wolf 25.[11]
Database references

HD 4628 (96 G. Piscium) is a main sequence star in the equatorial constellation of Pisces. It has a spectral classification of K2.5 V and an effective temperature of 5,829 K, giving it an orange-red hue with a slightly smaller mass and girth than our Sun. HD 4628 lies at a distance of approximately 24.3 light years from the Sun.[1] The apparent magnitude is just sufficient for this star to be viewed with the unaided eye. The star appears to be slightly older than our Sun—approximately 5.4 billion years old.[9] The surface activity is low and, based upon the detection of UV emission, it may have a relatively cool corona with a temperature of one million K.[12]

The star has a relatively high proper motion of 1.4 per year and is moving in our general direction with a radial velocity of −10.8[4] km/s. HD 4628 will make its closest approach to the Sun in about 32,000 years, when it comes within 20 ly (7.3 pc).[13] No definitive companion has yet been found in orbit around this star. In 1958 it was thought to have stellar companion that was also a flare star, but this was subsequently disproved.[14]


  1. ^ a b c d e f van Leeuwen, F. (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. Archived from the original on 2016-04-02. Vizier catalog entry
  2. ^ Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data. SIMBAD, Bibcode:1986EgUBV........0M.
  3. ^ a b c 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. ^ a b Nordström, B.; et al. (May 2014), "The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ~14000 F and G dwarfs", Astronomy and Astrophysics, 418: 989–1019, arXiv:astro-ph/0405198, Bibcode:2004A&A...418..989N, doi:10.1051/0004-6361:20035959.
  5. ^ Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191.
  6. ^ a b c d 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
  7. ^ van Belle, Gerard T.; von Braun, Kaspar (2009). "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars". The Astrophysical Journal. 694 (2): 1085–1098. arXiv:0901.1206. Bibcode:2009ApJ...694.1085V. doi:10.1088/0004-637X/694/2/1085.
  8. ^ a b Maldonado, J.; et al. (October 2010), "A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups", Astronomy and Astrophysics, 521: A12, arXiv:1007.1132, Bibcode:2010A&A...521A..12M, doi:10.1051/0004-6361/201014948
  9. ^ a b Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, arXiv:0807.1686, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785
  10. ^ Gould, B. A., Uranometria Argentina, Reprinted and updated by Pilcher, F, archived from the original on 2012-02-27, retrieved 2010-07-16
  11. ^ "HD 4628 -- High proper-motion Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-07-15.
  12. ^ Mathioudakis, M.; et al. (November 1994), "Detection of EUV emission from the low activity dwarf HD 4628: Evidence for a cool corona", Astronomy and Astrophysics, 291 (2): 517–520, Bibcode:1994A&A...291..517M.
  13. ^ Bailer-Jones, C. A. L. (March 2015), "Close encounters of the stellar kind", Astronomy & Astrophysics, 575: 13, arXiv:1412.3648, Bibcode:2015A&A...575A..35B, doi:10.1051/0004-6361/201425221, A35.
  14. ^ Hartkopf, W. I.; McAlister, H. A. (January 1984), "Binary stars unresolved by speckle interferometry. III", Publications of the Astronomical Society of the Pacific, 96: 105–116, Bibcode:1984PASP...96..105H, doi:10.1086/131309.

External links[edit]