Psi2 Lupi
Psi2 Lupi (ψ2 Lup) is a triple star[7] system in the constellation Lupus. It is visible to the naked eye with an apparent magnitude of 4.75.[2] Based upon an annual parallax shift of 8.97[1] mas as seen from Earth, it is located around 360 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.016±0.009 due to interstellar dust. This system is a member of the Upper Centaurus-Lupus subgroup of the Scorpius–Centaurus Association.[8]
- For other star systems with this Bayer designation, see ψ Lupi.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 15h 42m 41.02206s[1] |
| Declination | −34° 42′ 37.4617″[1] |
| Apparent magnitude (V) | 4.75[2] |
| Characteristics | |
| Spectral type | B5 V[3] |
| U−B color index | −0.570[2] |
| B−V color index | −0.146[2] |
| Variable type | Microvariable[3] |
| Astrometry | |
| Radial velocity (Rv) | +3.9±2.8[4] km/s |
| Proper motion (μ) | RA: −21.37[1] mas/yr Dec.: −29.98[1] mas/yr |
| Parallax (π) | 8.97 ± 0.27[1] mas |
| Distance | 360 ± 10 ly (111 ± 3 pc) |
| Absolute magnitude (MV) | −1.44[2] |
| Orbit[5] | |
| Period (P) | 12.26 d |
| Eccentricity (e) | 0.19 |
| Periastron epoch (T) | 2438252.97 ± 10.0 JD |
| Argument of periastron (ω) (secondary) | 82.8° |
| Semi-amplitude (K1) (primary) | 63.3 km/s |
| Semi-amplitude (K2) (secondary) | 66.4 km/s |
| Details | |
| Surface gravity (log g) | 4.29[3] cgs |
| Temperature | 15,135[3] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
The inner pair of stars in this system form a double-lined spectroscopic binary with an orbital period of 12.26 days and an eccentricity of 0.19. The two components are described as similar in appearance.[5] They have the spectrum of a B-type main sequence star with a stellar classification of B5 V.[3] The luminosity has a micro-variability with a frequency of 0.94483 cycles per day and an amplitude of 0.0067 in magnitude.[3] The third component is a magnitude 10 star at an angular separation of 0.51 arc seconds.[7]
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.
- Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement, 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168.
- Molenda-Zakowicz, J.; Polubek, G. (December 2005), "New beta Cephei and SPB Stars Discovered in Hipparcos Photometry", Acta Astronomica, 55: 375–388, Bibcode:2005AcA....55..375M.
- 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.
- Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy & Astrophysics, 424 (2): 727, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213.
- "psi02 Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-10.
- 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.
- 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.