Rho Lupi

Rho Lupi, Latinized from ρ Lupi, is a solitary^[11] star in the southern constellation of Lupus. It is visible to the naked eye with an apparent visual magnitude of 4.05.^[3] Based upon an annual parallax shift of 10.32 mas as seen from Earth, it is located about 316 light years from the Sun. It is a member of the Upper Centaurus–Lupus subgroup of the nearby Scorpius–Centaurus association.^[12]

Rho Lupi

A light curve for Rho Lupi, plotted from TESS data[1]
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Lupus
Right ascension	14h 37m 53.22583s[2]
Declination	−49° 25′ 32.9798″[2]
Apparent magnitude (V)	4.05[3]
Characteristics
Spectral type	B3/4 V[4]
U−B color index	−0.56[3]
B−V color index	−0.15[3]
Astrometry
Radial velocity (Rv)	8.00±7.40[5] km/s
Proper motion (μ)	RA: −28.26[2] mas/yr Dec.: −28.82[2] mas/yr
Parallax (π)	10.32 ± 0.16 mas[2]
Distance	316 ± 5 ly (97 ± 2 pc)
Absolute magnitude (MV)	−0.88[6]
Details
Mass	4.66[7] M☉
Radius	3.4[8] R☉
Luminosity	365[9] L☉
Temperature	15,947±542[7] K
Rotational velocity (v sin i)	166[7] km/s
Age	44[7] Myr
Other designations
ρ Lup, CD−48° 9198, FK5 3158, HD 128345, HIP 71536, HR 5453, SAO 225071.[10]
Database references
SIMBAD	data

This is a B-type main sequence star with a stellar classification of B3/4 V.^[4] It is a microvariable with a period of 10.7 hours and an amplitude of 0.0046 in magnitude.^[13] With an age of just 44^[7] million years, the star is spinning with a projected rotational velocity of 166 km/s.^[7] This is giving the star an oblate shape with an equatorial bulge that is an estimated 6% larger than the polar radius.^[14] It has an estimated 4.66^[7] times the mass of the Sun and about 3.4^[8] times the Sun's radius. It is radiating 365^[9] times the solar luminosity from its outer atmosphere at an effective temperature of 15,947 K.^[7]

References

1. MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, retrieved 24 September 2022.
2. 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.
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.
4. Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
5. 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.
6. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
7. David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
8. Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (3rd ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
9. McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
10. "rho Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-10.{{cite web}}: CS1 maint: postscript (link)
11. 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.
12. Chen, Christine H.; et al. (September 2012), "A Spitzer MIPS Study of 2.5-2.0 M_⊙ Stars in Scorpius–Centaurus", The Astrophysical Journal, 756 (2): 24, arXiv:1207.3415, Bibcode:2012ApJ...756..133C, doi:10.1088/0004-637X/756/2/133, S2CID 119278056, 133.
13. Koen, Chris; Eyer, Laurent (2002), "New periodic variables from the Hipparcos epoch photometry", Monthly Notices of the Royal Astronomical Society, 331 (1): 45–59, arXiv:astro-ph/0112194, Bibcode:2002MNRAS.331...45K, doi:10.1046/j.1365-8711.2002.05150.x, S2CID 10505995.
14. Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv:1204.2572, Bibcode:2012A&ARv..20...51V, doi:10.1007/s00159-012-0051-2, S2CID 119273474.