Lambda¹ Sculptoris

Lambda¹ Sculptoris, Latinized from λ¹ Sculptoris, is a double star system in the southern constellation of Sculptor. It is close to the lower limit of visibility to the naked eye, with a combined apparent visual magnitude of +6.05.[2] Based upon an annual parallax shift of 6.89 mas as measured from Earth,[1] it is located roughly 470 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.026 due to interstellar dust.[10]

Lambda¹ Sculptoris

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Sculptor
Right ascension	00^h 42^m 42.89190^s[1]
Declination	−38° 27′ 48.5416″[1]
Apparent magnitude (V)	+6.05[2] (6.612 + 7.041)[3]
Characteristics
Spectral type	B9.5 V[4] + A9(V)[5]
U−B color index	−0.13[2]
B−V color index	−0.03[2]
Astrometry
Radial velocity (Rv)	11.1±0.6[6] km/s
Proper motion (μ)	RA: +2.56[1] mas/yr Dec.: −6.72[1] mas/yr
Parallax (π)	6.89 ± 0.71[1] mas
Distance	approx. 470 ly (approx. 150 pc)
Absolute magnitude (MV)	+0.27[7]
Details
λ^1 Scl A
Mass	2.83±0.13[8] M☉
Luminosity	94[8] L☉
Temperature	10,351[8] K
Rotational velocity (v sin i)	35[8] km/s
Other designations
λ^1 Scl, CD−39° 175, HD 4065, HIP 3356, HR 185, SAO 192690, WDS J00427-3828AB[9]
Database references
SIMBAD	data

The brighter star, component A, has a visual magnitude of 6.6, while the secondary, component B, is magnitude 7.0.[3] As of 2000, the pair had an angular separation of 0.737 arc seconds along a position angle of 14.0°.[3] Component A is a blue-white hued B-type main sequence star with a stellar classification of B9.5 V.[4] It has 2.8 times the mass of the Sun and radiates 94 times the solar luminosity from its photosphere at an effective temperature of 10,351 K.[8]

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. Westerlund, B. E. (1963), "Three-colour photometry of early-type stars near the galactic poles", Monthly Notices of the Royal Astronomical Society, 127: 83, Bibcode:1963MNRAS.127...83W, doi:10.1093/mnras/127.1.83.
3. Fabricius, C.; Makarov, V. V. (April 2000), "Two-colour photometry for 9473 components of close Hipparcos double and multiple stars", Astronomy and Astrophysics, 356: 141–145, Bibcode:2000A&A...356..141F.
4. Houk, Nancy (1979), "Michigan catalogue of two-dimensional spectral types for the HD stars", Michigan Catalogue of Two-dimensional Spectral Types for the HD stars. Volume_3. Declinations −40_ƒ0 to −26_ƒ0, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, 3, Bibcode:1982mcts.book.....H.
5. Beavers, W. I.; Cook, D. B. (1980). "Scanner studies of composite spectra. I – Dwarfs". Astrophysical Journal Supplement Series. 44: 489. Bibcode:1980ApJS...44..489B. doi:10.1086/190702.
6. 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.
7. 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.
8. Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
9. "lam01 Scl – Double or multiple star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-05-30.
10. Paunzen, E.; et al. (October 2006), "An empirical temperature calibration for the Δ a photometric system. II. The A-type and mid F-type stars", Astronomy and Astrophysics, 458 (1): 293–296, arXiv:astro-ph/0607567, Bibcode:2006A&A...458..293P, doi:10.1051/0004-6361:20064889, S2CID 18219735.