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.[9] 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.
| Observation data Epoch J2000.0 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 mas[1] |
| Distance | 117.3 ± 0.6 ly (36.0 ± 0.2 pc) |
| Absolute magnitude (MV) | 0.65[6] |
| Details[7] | |
| ζ Lup A | |
| Mass | 2.56±0.10 M☉ |
| Radius | 9.00±0.18 R☉ |
| Luminosity | 49.9±1.7 L☉ |
| Surface gravity (log g) | 2.930±0.094 cgs |
| Temperature | 5,114±36 K |
| Metallicity [Fe/H] | 0.022±0.024 dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a probable binary star system.[10] 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.[11] It is 2.6 times more massive than the Sun and nine times larger. Zeta Lupi is 50 times more luminous than the Sun, emmiting this energy from its photosphere at an effective temperature of 5114 K.[7]
The secondary, component B, has a visual magnitude of 6.74.[3]
References
edit- ^ 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 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.
- ^ a b c d Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22
- ^ a b 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, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
- ^ 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.
- ^ 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.
- ^ a b Ottoni, G.; Udry, S.; Ségransan, D.; Buldgen, G.; Lovis, C.; Eggenberger, P.; Pezzotti, C.; Adibekyan, V.; Marmier, M.; Mayor, M.; Santos, N. C.; Sousa, S. G.; Lagarde, N.; Charbonnel, C. (2022-01-01). "CORALIE radial-velocity search for companions around evolved stars (CASCADES). I. Sample definition and first results: Three new planets orbiting giant stars". Astronomy and Astrophysics. 657: A87. arXiv:2201.01528. Bibcode:2022A&A...657A..87O. doi:10.1051/0004-6361/202040078. ISSN 0004-6361. Zeta Lupi's database entry at VizieR.
- ^ "zet Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-03.
- ^ 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ 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. arXiv:1109.4800. Bibcode:2012MNRAS.419.1637L. doi:10.1111/j.1365-2966.2011.19826.x. S2CID 117788450.