Lambda Ursae Minoris
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ursa Minor |
| Right ascension | 17h 16m 56.4107s[1] |
| Declination | +89° 02′ 15.734″[1] |
| Apparent magnitude (V) | +6.38[2] |
| Characteristics | |
| Spectral type | M3+ IIIa[3] |
| U−B color index | +1.79[4] |
| B−V color index | +1.57[4] |
| Variable type | SRb[5] |
| Astrometry | |
| Radial velocity (Rv) | +0.19[1] km/s |
| Proper motion (μ) | RA: −23.989[1] mas/yr Dec.: 3.463[1] mas/yr |
| Parallax (π) | 3.7084 ± 0.1329 mas[1] |
| Distance | 880 ± 30 ly (270 ± 10 pc) |
| Absolute magnitude (MV) | −0.85[6] |
| Details | |
| Radius | 64[1] R☉ |
| Luminosity | 741[1] L☉ |
| Temperature | 3,772[1] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Lambda Ursae Minoris (λ UMi, λ Ursae Minoris) is a star in the constellation Ursa Minor. It is an M-type red giant with an apparent magnitude of +6.38 and is approximately 880 light years from Earth.
Lambda Ursae Minoris is an asymptotic giant branch (AGB) star, a star that has exhausted its core hydrogen and helium and is now fusing material in shells outside its core.[7] AGB stars are often unstable and tend to pulsate, and Lambda Ursae Minoris is classified as a semiregular variable star and its brightness varies by about 0.1 magnitudes.[5] Its variability was discovered from Hipparcos astrometry and it was entered into the General Catalogue of Variable Stars in 1999.[8]
References
- ^ a b c d e f g h i 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.
- ^ Ducati, J. R. (2002). "VizieR On-line Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". VizieR On-line Data Catalog. Bibcode:2002yCat.2237....0D.
- ^ Yamashita, Y. (1967). "MK Spectral Types of Bright M-Type Stars". Publications of the Dominion Astrophysical Observatory Victoria. 13: 47. Bibcode:1967PDAO...13...47Y.
- ^ a b Hoffleit, Dorrit; Jaschek, Carlos (1991). The Bright star catalogue. Bibcode:1991bsc..book.....H.
- ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/GCVS. Bibcode:2009yCat....102025S.
- ^ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
- ^ Eggen, Olin J. (1992). "Asymptotic Giant Branch Stars Near the Sun". The Astronomical Journal. 104: 275. Bibcode:1992AJ....104..275E. doi:10.1086/116239.
- ^ Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (1999). "The 74th Special Name-list of Variable Stars". Information Bulletin on Variable Stars. 4659: 1. Bibcode:1999IBVS.4659....1K.
External links
- Lambda Ursae Minoris on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
- LAMBDA UMI (Lambda Ursae Minoris) – Jim Kaler
