Astronomy:HD 154577
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Ara[1] |
| Right ascension | 17h 10m 10.35091s[2] |
| Declination | −60° 43′ 43.5757″[2] |
| Apparent magnitude (V) | 7.385[3] |
| Characteristics | |
| Spectral type | K2.5Vk:[4] |
| U−B color index | +0.53[5] |
| B−V color index | +0.89[5] |
| Astrometry | |
| Radial velocity (Rv) | +8.8[6] km/s |
| Proper motion (μ) | RA: 70.96[2] mas/yr Dec.: 589.86[2] mas/yr |
| Parallax (π) | 73.41 ± 0.70[2] mas |
| Distance | 44.4 ± 0.4 ly (13.6 ± 0.1 pc) |
| Absolute magnitude (MV) | 6.71[3] |
| Details | |
| Mass | 0.68[7] M☉ |
| Radius | 0.68[8] R☉ |
| Luminosity | 0.24[9] L☉ |
| Surface gravity (log g) | 4.70[4] cgs |
| Temperature | 4,850[4] K |
| Metallicity [Fe/H] | −0.70[10] dex |
| Rotational velocity (v sin i) | 0.2[11] km/s |
| Age | 3.2[12] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
HD 154577 (Gliese 656) is a K-type main-sequence 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,[2] 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.[3] It is moving away from the Sun with a radial velocity of +9 km/s.[6]
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:,[4] 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[12] billion years old and appears to be spinning slowly with a projected rotational velocity of 0.2 km/s.[11] The star is radiating 24%[9] of the Sun's luminosity from its photosphere at an effective temperature of 4,850 K.[4]
As of 2005, this star is not known to host any planets.[7] No excess of infrared radiation has been detected of the type that would indicate the presence of an orbiting debris disk.[12]
References
- ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific 99 (617): 695. doi:10.1086/132034. Bibcode: 1987PASP...99..695R Constellation record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 3.0 3.1 3.2 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. Bibcode: 2009A&A...501..941H. Note: see VizieR catalogue V/130.
- ↑ 4.0 4.1 4.2 4.3 4.4 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. Bibcode: 2006AJ....132..161G.
- ↑ 5.0 5.1 Cousins, A. W. J. (1973). "UBV photometry of some southern stars". Monthly Notes of the Astronomical Society of Southern Africa 32: 11. Bibcode: 1973MNSSA..32...11C.
- ↑ 6.0 6.1 Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". University of Toronto: International Astronomical Union. Bibcode: 1967IAUS...30...57E.
- ↑ 7.0 7.1 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. Bibcode: 2005A&A...437.1127S.
- ↑ 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, Bibcode: 2007ApJS..168..297T.
- ↑ 9.0 9.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 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, Bibcode: 2012A&A...545A..32A.
- ↑ 11.0 11.1 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, Bibcode: 2005ApJS..159..141V.
- ↑ 12.0 12.1 12.2 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. Bibcode: 2009ApJ...705...89L.
- ↑ "LHS 3268 -- High proper-motion star". SIMBAD. Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=LHS+3268.
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