Astronomy:HD 154577

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Short description: Star in the constellation Ara
HD 154577
Observation data
Equinox J2000.0]] (ICRS)
Constellation Ara
Right ascension  17h 10m 10.35091s[1]
Declination −60° 43′ 43.5757″[1]
Apparent magnitude (V) 7.385[2]
Characteristics
Spectral type K2.5Vk:[3]
U−B color index +0.53[4]
B−V color index +0.89[4]
Astrometry
Radial velocity (Rv)+8.8[5] km/s
Proper motion (μ) RA: 70.96[1] mas/yr
Dec.: 589.86[1] mas/yr
Parallax (π)73.41 ± 0.70[1] mas
Distance44.4 ± 0.4 ly
(13.6 ± 0.1 pc)
Absolute magnitude (MV)6.71[2]
Details
Mass0.68[6] M
Radius0.68[7] R
Luminosity0.24[8] L
Surface gravity (log g)4.70[3] cgs
Temperature4,850[3] K
Metallicity [Fe/H]−0.70[9] dex
Rotational velocity (v sin i)0.2[10] km/s
Age3.2[11] Gyr
Other designations
CD-60 6576, GCTP, GJ 656, HD 154577, HIP 83990, LHS 3268, LTT 6833, SAO 253819.[12]
Database references
SIMBADdata
ARICNSdata

HD 154577 (Gliese 656) is a solar-type star in the southern constellation of Ara. It is a high proper motion star and, based upon an annual parallax shift of 73.41 mas,[1] is located about 44 light years from the Sun. The star is too faint to be readily visible to the naked eye, having an apparent visual magnitude of 7.4.[2] It is moving away from the Sun with a radial velocity of +9 km/s.[5]

This star has only 68% of the Sun's mass and radius, an effective temperature of 4,850 K and a stellar classification of K2.5Vk:,[3] which indicates it is a K-type main sequence star. (The 'k' suffix indicates there are interstellar absorption features in the spectra, while ':' means there is some uncertainty about the classification.) It is about 3.2[11] billion years old and appears to be spinning slowly with a projected rotational velocity of 0.2 km/s.[10] The star is radiating 24%[8] of the Sun's luminosity from its photosphere at an effective temperature of 4,850 K.[3]

As of 2005, this star is not known to host any planets.[6] No excess of infrared radiation has been detected of the type that would indicate the presence of an orbiting debris disk.[11]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 Holmberg, J.; Nordström, B.; Andersen, J. (July 2009). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". Astronomy and Astrophysics Supplement Series 501 (3): 941–947. doi:10.1051/0004-6361/200811191. Bibcode2009A&A...501..941H.  Note: see VizieR catalogue V/130.
  3. 3.0 3.1 3.2 3.3 3.4 Gray, R. O. (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. doi:10.1086/504637. Bibcode2006AJ....132..161G. 
  4. 4.0 4.1 Cousins, A. W. J. (1973). "UBV photometry of some southern stars". Monthly Notes of the Astronomical Society of Southern Africa 32: 11. Bibcode1973MNSSA..32...11C. 
  5. 5.0 5.1 Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". University of Toronto: International Astronomical Union. Bibcode1967IAUS...30...57E. 
  6. 6.0 6.1 Santos, N. C. (July 2005). "Spectroscopic metallicities for planet-host stars: Extending the samples". Astronomy and Astrophysics 437 (3): 1127–1133. doi:10.1051/0004-6361:20052895. Bibcode2005A&A...437.1127S. 
  7. Takeda, Genya et al. (February 2007), "Structure and Evolution of Nearby Stars with Planets. II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog", The Astrophysical Journal Supplement Series 168 (2): 297–318, doi:10.1086/509763, Bibcode2007ApJS..168..297T. 
  8. 8.0 8.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  9. Adibekyan, V. Zh. et al. (September 2012), "Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program. Galactic stellar populations and planets", Astronomy & Astrophysics 545: 15, doi:10.1051/0004-6361/201219401, A32, Bibcode2012A&A...545A..32A. 
  10. 10.0 10.1 Valenti, Jeff A.; Fischer, Debra A. (July 2005), "Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs", The Astrophysical Journal Supplement Series 159 (1): 141–166, doi:10.1086/430500, Bibcode2005ApJS..159..141V. 
  11. 11.0 11.1 11.2 Lawler, S. M. (November 2009). "Explorations Beyond the Snow Line: Spitzer/IRS Spectra of Debris Disks Around Solar-type Stars". The Astrophysical Journal 705 (1): 89–111. doi:10.1088/0004-637X/705/1/89. Bibcode2009ApJ...705...89L. 
  12. "LHS 3268 -- High proper-motion star". SIMBAD. Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=LHS+3268.