HR 5256 is a star located thirty-three[1] light-years away from the Sun in the northern circumpolar constellation of Ursa Major. It has an orange hue and is a challenge to view with the naked eye, having an apparent visual magnitude of 6.52[2] The distance to this star is very nearly 10 parsecs, so the absolute magnitude of 6.51[3] is nearly the same as the star's apparent magnitude. HR 5256 is drifting nearer to the Sun with a radial velocity of −26.4 km/s,[1] and will make its closest approach to the Sun in about 333,000±16,000 years, when it will be at a distance of 12.72 ± 0.65 light-years.[9]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| Right ascension | 13h 57m 32.0592s[1] |
| Declination | +61° 29′ 34.2994″[1] |
| Apparent magnitude (V) | 6.52[2][3] |
| Characteristics | |
| Spectral type | K3 V[4] |
| U−B color index | 0.98[5] |
| B−V color index | 1.01[5] |
| Astrometry | |
| Radial velocity (Rv) | −26.376±0.0011[1] km/s |
| Proper motion (μ) | RA: −32.074±0.063[1] mas/yr Dec.: 216.317±0.049[1] mas/yr |
| Parallax (π) | 99.2285 ± 0.0232 mas[1] |
| Distance | 32.869 ± 0.008 ly (10.078 ± 0.002 pc) |
| Absolute magnitude (MV) | 6.51[3] |
| Details[3] | |
| Mass | 0.82 M☉ |
| Radius | 0.78[6] R☉ |
| Luminosity | 0.28 L☉ |
| Surface gravity (log g) | 4.57 cgs |
| Temperature | 4,811 K |
| Metallicity [Fe/H] | 0.17[7] dex |
| Rotational velocity (v sin i) | 4.6 km/s |
| Age | 5.36 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This object is an ordinary K-type main-sequence star with a stellar classification of K3 V,[4] which indicates it is undergoing core hydrogen fusion. It is over five billion years of age and is spinning slowly with a projected rotational velocity of 4.6 km/s.[3] The star has an estimated 82%[3] of the Sun's mass and 78% of the Sun's radius.[6] It is radiating just 28% of the luminosity of the Sun from its photosphere at an effective temperature of 4,811 K.[3]
References
edit- ^ a b c d e f g h Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b Oja, T. (August 1991). "UBV photometry of stars whose positions are accurately known. VI". Astronomy and Astrophysics Supplement Series. 89 (2): 415–419. Bibcode:1991A&AS...89..415O.
- ^ a b c d e f g Luck, R. Earle (January 2017). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 19. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. S2CID 119511744. 21.
- ^ a b Marrese, P. M.; Boschi, F.; Munari, U. (August 2003). "High resolution spectroscopy over lambda lambda 8500-8750 Å for GAIA. IV. Extending the cool MK stars sample". Astronomy and Astrophysics. 406: 995–999. Bibcode:2003A&A...406..995M. doi:10.1051/0004-6361:20030647.
- ^ a b "ARICNS 4C04262". ARICNS. Astronomisches Rechen-Institut Heidelberg. March 4, 1998. Archived from the original on 2011-06-07. Retrieved 2010-12-07.
- ^ a b 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. arXiv:astro-ph/0607235. Bibcode:2007ApJS..168..297T. doi:10.1086/509763. S2CID 18775378. Data obtained from a VizieR query.
- ^ Soubiran, C.; Bienaymé, O.; Mishenina, T. V.; Kovtyukh, V. V. (March 2008). "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants". Astronomy and Astrophysics. 480 (1): 91–101. arXiv:0712.1370. Bibcode:2008A&A...480...91S. doi:10.1051/0004-6361:20078788. S2CID 16602121.
- ^ "HD 122064". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-10-14.
- ^ Bailer-Jones, C.A.L.; et al. (2018). "New stellar encounters discovered in the second Gaia data release". Astronomy & Astrophysics. 616: A37. arXiv:1805.07581. Bibcode:2018A&A...616A..37B. doi:10.1051/0004-6361/201833456. S2CID 56269929.