Omicron Lupi
Omicron Lupi (ο Lup) is a binary star[3] in the southern constellation of Lupus. It is a visible to the naked eye with a combined apparent visual magnitude of 4.323.[2] Based upon an annual parallax shift of 8.07 mas as seen from Earth,[1] it is located around 400 light years from the Sun, give or take 30 light years. At that distance, the visual magnitude of the system is diminished by an extinction factor of 0.13±0.01 due to interstellar dust.[5] It is a member of the Upper Centaurus Lupus[8] subgroup of the nearby Scorpius–Centaurus Association.[6]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 14h 51m 38.30289s[1] |
| Declination | −43° 34′ 31.2965″[1] |
| Apparent magnitude (V) | 4.323[2] (4.84 + 5.27)[3] |
| Characteristics | |
| Spectral type | B5 IV[3] |
| U−B color index | −0.620[2] |
| B−V color index | −0.159[2] |
| Astrometry | |
| Radial velocity (Rv) | +7.30±0.74[4] km/s |
| Proper motion (μ) | RA: −25.20[1] mas/yr Dec.: −27.13[1] mas/yr |
| Parallax (π) | 8.07 ± 0.59[1] mas |
| Distance | 400 ± 30 ly (124 ± 9 pc) |
| Absolute magnitude (MV) | −1.2±0.3[5] |
| Details | |
| Mass | 5.7±0.2[5] M☉ |
| Radius | 3.5[5] R☉ |
| Luminosity | 1,260[5] L☉ |
| Surface gravity (log g) | 4.1±0.1[5] cgs |
| Temperature | 18,000[6] K |
| Rotational velocity (v sin i) | 25[6] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a visual binary star system with the components having an angular separation of 0.1 arc seconds.[8] The primary, component A, is a magnitude 4.84 B-type subgiant star with a stellar classification of B5 V.[3] It displays radial velocity variations indicating it has an unseen second companion orbiting at a separation of at least 17 AU with a period of 27 years or more.[6] The spectrum of the primary displays a Zeeman effect indicating a magnetic field with a strength ranging from −94 to 677 G.[6] The visible companion, component B, has a visual magnitude of 5.27.[3]
References
- 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.
- Cousins, A. W. J. (1973), "Revised zero points and UBV photometry of stars in the Harvard E and F regions", Memoirs of the Royal Astronomical Society, 77: 223–236, Bibcode:1973MmRAS..77..223C.
- 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.
- 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, A61.
- Petit, V.; et al. (February 2013), "A magnetic confinement versus rotation classification of massive-star magnetospheres" (PDF), Monthly Notices of the Royal Astronomical Society, 429 (1): 398–422, arXiv:1211.0282, Bibcode:2013MNRAS.429..398P, doi:10.1093/mnras/sts344.
- Alecian, E.; et al. (December 2011), "First HARPSpol discoveries of magnetic fields in massive stars", Astronomy & Astrophysics, 536: 4, arXiv:1111.3433, Bibcode:2011A&A...536L...6A, doi:10.1051/0004-6361/201118354, L6.
- "omi Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-10.
- 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, 133.