| Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
|---|---|
| Constellation | Libra |
| Right ascension | 15h 37m 01.45020s [1] |
| Declination | −28° 08′ 06.2926″ [1] |
| Apparent magnitude (V) | 3.628 [2] |
| Characteristics | |
| Spectral type | K3 III [3] |
| U−B color index | +1.586 [2] |
| B−V color index | +1.374 [2] |
| Astrometry | |
| Radial velocity (Rv) | −24.9±0.7 [4] km/s |
| Proper motion (μ) |
RA: −12.82
[1]
mas/
yr Dec.: −4.15 [1] mas/ yr |
| Parallax (π) | 14.58 ± 0.19 mas [1] |
| Distance | 224 ± 3
ly (68.6 ± 0.9 pc) |
| Absolute magnitude (MV) | −0.28 [5] |
| Details [6] | |
| Mass | 1.67 M☉ |
| Radius | 31.5 [7] R☉ |
| Luminosity | 309 L☉ |
| Surface gravity (log g) | 1.58 cgs |
| Temperature | 4,135±20 K |
| Metallicity [Fe/H] | −0.02 dex |
| Age | 3.14 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Upsilon Librae (υ Lib, υ Librae) is the Bayer designation for a double star [9] in the zodiac constellation Libra. With an apparent visual magnitude of 3.628, [2] it is visible to the naked eye. The distance to this star, based upon an annual parallax shift of 14.58, [1] is around 224 light years. It has a magnitude 10.8 companion at an angular separation of 2.0 arc seconds along a position angle of 151°, as of 2002. [10]
The brighter component is an evolved K-type giant star with a stellar classification of K3 III. [3] The measured angular diameter, after correction for limb darkening, is 4.27±0.05 mas. [11] At the estimated distance of the star, this yields a physical size of about 31.5 times the radius of the Sun. [7] It has 1.67 times the mass of the Sun and radiates 309 times the solar luminosity from its outer atmosphere at an effective temperature of 4,135 K. [6] The star is about three billion years old. [6]
Upsilon Librae will be the brightest star in the night sky in about 2.3 million years, [12] and will peak in brightness with an apparent magnitude of –0.46. [12]
References
- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv: 0708.1752, Bibcode: 2007A&A...474..653V, doi: 10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d Celis S., L. (October 1975), "Photoelectric photometry of late-type variable stars", Astronomy and Astrophysics Supplement Series, 22: 9–17, Bibcode: 1975A&AS...22....9C.
- ^ a b Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode: 1982mcts.book.....H
- ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv: 1208.3048, Bibcode: 2012A&A...546A..61D, doi: 10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ Ryon, Jenna; et al. (August 2009), "Comparing the Ca ii H and K Emission Lines in Red Giant Stars", Publications of the Astronomical Society of the Pacific, 121 (882): 842, arXiv: 0907.3346, Bibcode: 2009PASP..121..842R, doi: 10.1086/605456, S2CID 17821279.
- ^ a b c Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 23, arXiv: 1507.01466, Bibcode: 2015AJ....150...88L, doi: 10.1088/0004-6256/150/3/88, S2CID 118505114, 88.
- ^
a
b Lang, Kenneth R. (2006),
Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.),
Birkhäuser,
ISBN
3-540-29692-1. The radius (R*) is given by:
- ^ "ups Lib". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-01-30.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv: 0806.2878, Bibcode: 2008MNRAS.389..869E, doi: 10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode: 2001AJ....122.3466M, doi: 10.1086/323920
- ^ Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode: 2005A&A...431..773R, doi: 10.1051/0004-6361:20042039.
- ^ a b Tomkin, Jocelyn (April 1998). "Once and Future Celestial Kings". Sky and Telescope. 95 (4): 59–63. Bibcode: 1998S&T....95d..59T. based on computations from HIPPARCOS data. (The calculations exclude stars whose distance or proper motion is uncertain.) PDF[ permanent dead link]
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| Galaxies |
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| Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
|---|---|
| Constellation | Libra |
| Right ascension | 15h 37m 01.45020s [1] |
| Declination | −28° 08′ 06.2926″ [1] |
| Apparent magnitude (V) | 3.628 [2] |
| Characteristics | |
| Spectral type | K3 III [3] |
| U−B color index | +1.586 [2] |
| B−V color index | +1.374 [2] |
| Astrometry | |
| Radial velocity (Rv) | −24.9±0.7 [4] km/s |
| Proper motion (μ) |
RA: −12.82
[1]
mas/
yr Dec.: −4.15 [1] mas/ yr |
| Parallax (π) | 14.58 ± 0.19 mas [1] |
| Distance | 224 ± 3
ly (68.6 ± 0.9 pc) |
| Absolute magnitude (MV) | −0.28 [5] |
| Details [6] | |
| Mass | 1.67 M☉ |
| Radius | 31.5 [7] R☉ |
| Luminosity | 309 L☉ |
| Surface gravity (log g) | 1.58 cgs |
| Temperature | 4,135±20 K |
| Metallicity [Fe/H] | −0.02 dex |
| Age | 3.14 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Upsilon Librae (υ Lib, υ Librae) is the Bayer designation for a double star [9] in the zodiac constellation Libra. With an apparent visual magnitude of 3.628, [2] it is visible to the naked eye. The distance to this star, based upon an annual parallax shift of 14.58, [1] is around 224 light years. It has a magnitude 10.8 companion at an angular separation of 2.0 arc seconds along a position angle of 151°, as of 2002. [10]
The brighter component is an evolved K-type giant star with a stellar classification of K3 III. [3] The measured angular diameter, after correction for limb darkening, is 4.27±0.05 mas. [11] At the estimated distance of the star, this yields a physical size of about 31.5 times the radius of the Sun. [7] It has 1.67 times the mass of the Sun and radiates 309 times the solar luminosity from its outer atmosphere at an effective temperature of 4,135 K. [6] The star is about three billion years old. [6]
Upsilon Librae will be the brightest star in the night sky in about 2.3 million years, [12] and will peak in brightness with an apparent magnitude of –0.46. [12]
References
- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv: 0708.1752, Bibcode: 2007A&A...474..653V, doi: 10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d Celis S., L. (October 1975), "Photoelectric photometry of late-type variable stars", Astronomy and Astrophysics Supplement Series, 22: 9–17, Bibcode: 1975A&AS...22....9C.
- ^ a b Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode: 1982mcts.book.....H
- ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv: 1208.3048, Bibcode: 2012A&A...546A..61D, doi: 10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ Ryon, Jenna; et al. (August 2009), "Comparing the Ca ii H and K Emission Lines in Red Giant Stars", Publications of the Astronomical Society of the Pacific, 121 (882): 842, arXiv: 0907.3346, Bibcode: 2009PASP..121..842R, doi: 10.1086/605456, S2CID 17821279.
- ^ a b c Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 23, arXiv: 1507.01466, Bibcode: 2015AJ....150...88L, doi: 10.1088/0004-6256/150/3/88, S2CID 118505114, 88.
- ^
a
b Lang, Kenneth R. (2006),
Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.),
Birkhäuser,
ISBN
3-540-29692-1. The radius (R*) is given by:
- ^ "ups Lib". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-01-30.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv: 0806.2878, Bibcode: 2008MNRAS.389..869E, doi: 10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode: 2001AJ....122.3466M, doi: 10.1086/323920
- ^ Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode: 2005A&A...431..773R, doi: 10.1051/0004-6361:20042039.
- ^ a b Tomkin, Jocelyn (April 1998). "Once and Future Celestial Kings". Sky and Telescope. 95 (4): 59–63. Bibcode: 1998S&T....95d..59T. based on computations from HIPPARCOS data. (The calculations exclude stars whose distance or proper motion is uncertain.) PDF[ permanent dead link]
| Stars |
| ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||
| |||||||||||||
| Galaxies |
| ||||||||||||