Lambda Ursae Majoris
From Wikipedia, the free encyclopedia
 Location of λ Ursae Majoris (circled) |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Ursa Major |
| Right ascension | 10h 17m 05.78287s[1] |
| Declination | +42° 54′ 51.6808″[1] |
| Apparent magnitude (V) | +3.45[2] |
| Characteristics | |
| Spectral type | A2 IV[3] |
| U−B color index | +0.06[2] |
| B−V color index | +0.03[2] |
| Astrometry | |
| Radial velocity (Rv) | +18.1[4] km/s |
| Proper motion (μ) | RA: –180.65[1] mas/yr Dec.: –46.07[1] mas/yr |
| Parallax (π) | 23.72 ± 0.78[1] mas |
| Distance | 138 ± 5 ly (42 ± 1 pc) |
| Details | |
| Surface gravity (log g) | 3.90[5] |
| Temperature | 9,280[5] K |
| Metallicity [Fe/H] | +0.20[5] dex |
| Rotational velocity (v sin i) | 50[6] km/s |
| Age | 4.1 × 108[7] years |
| Other designations | |
Lambda Ursae Majoris (λ UMa, λ Ursae Majoris) is a star in the constellation Ursa Major. It also has the proper names Tania Borealis (former Tania borealis[9]) meaning "the Northern (star) of Tania." The word Tania comes from the Arabic phrase (al-Qafzah) al-Thāniyah meaning "the Second (Leap)" (the distinctions "northern" (borealis) is added in Latin), and Alkafzah Borealis[citation needed]. With Mu Ursae Majoris, they were Chung Tae （中台）, the Middle Dignitary, in Chinese astronomy.[10]
Lambda Ursae Majoris is a white A-type subgiant with an apparent magnitude of 3.5m. It is approximately 135 light years from the Earth.
[edit] References
- ^ a b c d e van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, Bibcode 2007A&A...474..653V, doi:10.1051/0004-6361:20078357
- ^ a b c Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99), Bibcode 1966CoLPL...4...99J
- ^ Cowley, A. et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal 74: 375–406, Bibcode 1969AJ.....74..375C, doi:10.1086/110819
- ^ Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; John Frederick, Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode 1967IAUS...30...57E
- ^ a b c Hill, G. M. (February 1995), "Compositional differences among the A-type stars. 2: Spectrum synthesis up to V sin i = 110 km/s", Astronomy and Astrophysics 294 (2): 536–546, Bibcode 1995A&A...294..536H
- ^ Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics 463 (2): 671–682, Bibcode 2007A&A...463..671R, doi:10.1051/0004-6361:20065224
- ^ Su, K. Y. L. et al. (December 2006), "Debris Disk Evolution around A Stars", The Astrophysical Journal 653 (1): 675–689, Bibcode 2006ApJ...653..675S, doi:10.1086/508649
- ^ "lam UMa -- High proper-motion Star", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Lambda+Ursae+Majoris, retrieved 2012-01-20
- ^ Piazzi, G., The Palermo Catalogue, Palermo, 1814.
- ^ Allen, Richard Hinckley (1899). Star-Names and Their Meanings. New York: G. E. Stechert., p.443.
|
|||||||||||||||||
 |
This subgiant star-related article is a stub. You can help Wikipedia by expanding it. |
