Phi2 Lupi

Phi² Lupi, Latinized from φ² Lupi, is a solitary^[10] star in the southern constellation of Lupus. With an apparent magnitude of 4.535,^[2] it is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 6.28 mas as seen from Earth, it is located around 520 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.052±0.013 due to interstellar dust. It is a member of the Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association.^[11]

For other stars with this Bayer designation, see φ Lupi.

Phi² Lupi

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Lupus
Right ascension	15h 23m 09.35005s[1]
Declination	−36° 51′ 30.5521″[1]
Apparent magnitude (V)	4.535[2]
Characteristics
Spectral type	B4 V[3][4]
U−B color index	−0.648[2]
B−V color index	−0.161[2]
Astrometry
Radial velocity (Rv)	+0.80±2.70[5] km/s
Proper motion (μ)	RA: −18.24[1] mas/yr Dec.: −20.72[1] mas/yr
Parallax (π)	6.28 ± 0.20 mas[1]
Distance	520 ± 20 ly (159 ± 5 pc)
Absolute magnitude (MV)	−1.47[6]
Details
Mass	6.1±0.1[4] M☉
Radius	3.4[7] R☉
Luminosity	800[8] L☉
Temperature	16,780[3] K
Rotational velocity (v sin i)	141±6[3] km/s
Age	39.9±10.1[4] Myr
Other designations
φ2 Lup, CD−36° 10103, FK5 1403, HD 136664, HIP 75304, HR 5712, SAO 206580.[9]
Database references
SIMBAD	data

This is an ordinary B-type main sequence star with a stellar classification of B4 V.^[3][4] It has an estimated 6.1^[4] times the mass of the Sun and about 3.4^[7] times the Sun's radius. The star is roughly 40^[4] million years and is spinning with a projected rotational velocity of 141 km/s.^[3] It is radiating about 800^[8] times the solar luminosity from its photosphere at an effective temperature of 16,780 K.^[3]

References

1. 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.
2. Kozok, J. R. (September 1985), "Photometric observations of emission B-stars in the southern Milky Way", Astronomy and Astrophysics Supplement Series, 61: 387–405, Bibcode:1985A&AS...61..387K.
3. Bragança, G. A.; et al. (November 2012), "Projected Rotational Velocities and Stellar Characterization of 350 B Stars in the Nearby Galactic Disk", The Astronomical Journal, 144 (5): 10, arXiv:1208.1674, Bibcode:2012AJ....144..130B, doi:10.1088/0004-6256/144/5/130, S2CID 118868235, 130.
4. Tetzlaff, N.; et al. (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, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
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. Pasinetti Fracassini, L. E.; et al. (2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy & Astrophysics, 367 (2): 521–24, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
8. 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.
9. "phi02 Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-10.{{cite web}}: CS1 maint: postscript (link)
10. 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.
11. 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.