Astronomy:Zeta Lupi
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 15h 12m 17.09595s[1] |
| Declination | −52° 05′ 57.2919″[1] |
| Apparent magnitude (V) | 3.41[2] (3.50 + 6.74)[3] |
| Characteristics | |
| Spectral type | G7 III[4] |
| U−B color index | +0.66[2] |
| B−V color index | +0.92[2] |
| Astrometry | |
| Radial velocity (Rv) | −10.0±0.6[5] km/s |
| Proper motion (μ) | RA: −112.92[1] mas/yr Dec.: −71.18[1] mas/yr |
| Parallax (π) | 27.80 ± 0.15[1] mas |
| Distance | 117.3 ± 0.6 ly (36.0 ± 0.2 pc) |
| Absolute magnitude (MV) | 0.65[6] |
| Details | |
| ζ Lup A | |
| Mass | 2.29[6] M☉ |
| Radius | 10[7] R☉ |
| Luminosity | 53[8] L☉ |
| Surface gravity (log g) | 3.01[9] cgs |
| Temperature | 5,335[8] K |
| Metallicity [Fe/H] | 0.00±0.02[9] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
ζ Lupi (Latinised as Zeta Lupi) is the brighter component of a wide double star in the constellation Lupus, consisting of an orange-hued primary and a fainter secondary with a golden-yellow hue.[11] It is visible to the naked eye with a combined apparent visual magnitude of 3.41.[2] Based upon an annual parallax shift of 27.80[1] mas as seen from Earth, it is located 117.3 light-years from the Sun.
This is a probable binary star system.[12] As of 2013, the pair had an angular separation of 71.20 arcseconds along a position angle of 249°.[3] The primary, component A, is an evolved G-type giant star with a visual magnitude of 3.50[3] and a stellar classification of G7 III.[4] This is a red clump star, indicating that it is generating energy through the thermonuclear fusion of helium in its core region.[13] Its measured angular diameter is 2.55±0.13 mas,[14] which, at the estimated distance of Zeta Lupi, yields a physical size of about 10 times the radius of the Sun.[7]
The secondary, component B, has a visual magnitude of 6.74.[3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 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.
- ↑ 2.0 2.1 2.2 2.3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode: 1966CoLPL...4...99J.
- ↑ 3.0 3.1 3.2 3.3 Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M, http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds, retrieved 2015-07-22
- ↑ 4.0 4.1 Gray, R. O. et al. (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.
- ↑ 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, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ 6.0 6.1 Pizzolato, N. et al. (September 2000), "Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases", Astronomy and Astrophysics 361: 614–628, Bibcode: 2000A&A...361..614P.
- ↑ 7.0 7.1 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41. The radius (R*) is given by:
- [math]\displaystyle{ \begin{align} 2\cdot R_* & = \frac{(36.0\cdot 2.55\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\ & \approx 19.7\cdot R_{\bigodot} \end{align} }[/math]
- ↑ 8.0 8.1 McDonald, I. et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–57, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode: 2012MNRAS.427..343M.
- ↑ 9.0 9.1 Soubiran, Caroline et al. (June 2016), "The PASTEL catalogue: 2016 version", Astronomy & Astrophysics 591: 7, doi:10.1051/0004-6361/201628497, A118, Bibcode: 2016A&A...591A.118S.
- ↑ "zet Lup". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=zet+Lup.
- ↑ Streicher, M. (June 2007), "Lupus: a wild animal", Monthly Notes of the Astronomical Society of South Africa 66 (5 and 6): 124–127, Bibcode: 2007MNSSA..66..124S.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Laney, C. D. et al. (2012). "A new Large Magellanic Cloud K-band distance from precision measurements of nearby red clump stars". Monthly Notices of the Royal Astronomical Society 419 (2): 1637. doi:10.1111/j.1365-2966.2011.19826.x. Bibcode: 2012MNRAS.419.1637L.
- ↑ Richichi, A. et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431 (2): 773–777, doi:10.1051/0004-6361:20042039, Bibcode: 2005A&A...431..773R.
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