Astronomy:Gamma Lupi
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 15h 35m 08.44835s[1] |
| Declination | −41° 10′ 00.3247″[1] |
| Apparent magnitude (V) | 2.77[2] |
| Characteristics | |
| Spectral type | B2 IV[3] |
| U−B color index | −0.82[4] |
| B−V color index | −0.20[4] |
| Astrometry | |
| Radial velocity (Rv) | +2.3[5] km/s |
| Proper motion (μ) | RA: −15.62[1] mas/yr Dec.: −25.43[1] mas/yr |
| Parallax (π) | 7.75 ± 0.50[1] mas |
| Distance | 420 ± 30 ly (129 ± 8 pc) |
| Absolute magnitude (MV) | −2.4[2] |
| Orbit[6] | |
| Primary | Aa |
| Companion | Ab |
| Period (P) | 2.85 days |
| Semi-major axis (a) | 16.0–19.3 R☉ |
| Eccentricity (e) | 0 |
| Semi-amplitude (K1) (primary) | 26.7±1.0 km/s |
| Orbit[6] | |
| Primary | A |
| Companion | B |
| Period (P) | 167.3+21.5 −7.2 yr |
| Semi-major axis (a) | 0.970″+0.343″ −0.240″" (125 astronomical unit|AU) |
| Eccentricity (e) | 0.826+0.082 −0.181 |
| Inclination (i) | 93.04+1.45 −0.89° |
| Longitude of the node (Ω) | 91.20+0.52 −0.35° |
| Periastron epoch (T) | 1885.7+2.9 −4.0 |
| Argument of periastron (ω) (secondary) | 286.9+12.0 −5.9° |
| Details[6] | |
| γ Lup Aa | |
| Mass | 6–10 M☉ |
| Radius | 3.92–5.39 R☉ |
| Luminosity | 2,570–4,700 L☉ |
| Surface gravity (log g) | 3.867–4.130 cgs |
| Temperature | 20,900[2] K |
| Rotational velocity (v sin i) | 270[7] km/s |
| Age | 16.7+5.0 −6.6 Myr |
| γ Lup Ab | |
| Mass | 0.72–1.93 M☉ |
| Radius | 2.00–3.47 R☉ |
| Luminosity | 2.39–10.7 L☉ |
| Surface gravity (log g) | 3.515–3.803 cgs |
| Temperature | 4,140–7,210 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Gamma Lupi, Latinized from γ Lupi, is a triple star system in the constellation of Lupus. It is easily visible to the naked eye, having an apparent magnitude of 2.77. It is also known in ancient Chinese astronomy as 騎官一 or "the 1st (star) of the Cavalry Officer". With a telescope, Gamma Lupi can be resolved into a binary star system in close orbit. This is known as the Gamma Lupi AB system, often abbreviated as γ Lupi AB or γ Lup AB.
The system has a hierarchical architecture. The primary, Gamma Lupi A is itself a spectroscopic binary with an orbital period of 2.849769 days.[6] Although the system does not show eclipses, the hotter star of the pair heats the side of the cooler star that faces it, and as they orbit each other the combined starlight varies in brightness by about 0.02 magnitudes, as seen from the Earth.[10] The outer component, Gamma Lupi B, is widely-separated (125 astronomical units) and has an orbital period of 170 years.[6]
This star is a proper motion member of the Upper Centaurus–Lupus sub-group in the Scorpius–Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.[2]
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (November 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 de Geus, E. J.; de Zeeuw, P. T.; Lub, J. (June 1989), "Physical parameters of stars in the Scorpio-Centaurus OB association", Astronomy and Astrophysics 216 (1–2): 44–61, Bibcode: 1989A&A...216...44D
- ↑ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode: 2011MNRAS.410..190T
- ↑ 4.0 4.1 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
- ↑ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick, eds., "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 (University of Toronto: International Astronomical Union) 30: p. 57, Bibcode: 1967IAUS...30...57E
- ↑ 6.0 6.1 6.2 6.3 6.4 Jerzykiewicz, M.; Pigulski, A.; Michalska, G.; Moździerski, D.; Ratajczak, M.; Handler, G.; Moffat, A. F. J.; Pablo, H. et al. (June 2021). "BRITE observations of ν Centauri and γ Lupi, the first non-eclipsing members of the new class of nascent binaries". Monthly Notices of the Royal Astronomical Society 503 (4): 5554–5568. doi:10.1093/mnras/stab846. Bibcode: 2021MNRAS.503.5554J.
- ↑ Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago 239 (1): 1, Bibcode: 1970CoAsi.239....1B
- ↑ "* gam Lup". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+gam+Lup.
- ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html.
- ↑ "gam Lup". AAVSO. https://www.aavso.org/vsx/index.php?view=detail.top&oid=17893.
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