Sigma Sculptoris

Sigma Sculptoris

An ultraviolet light curve for Sigma Sculptoris, adapted from Manfroid and Renson (1994)[1]
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Sculptor
Right ascension	01^h 02^m 26.43280^s[2]
Declination	−31° 33′ 07.2237″[2]
Apparent magnitude (V)	+5.54[3]
Characteristics
Spectral type	A2V[4]
U−B color index	+0.13[3]
B−V color index	+0.06[3]
Astrometry
Radial velocity (Rv)	−15.40±0.50[5] km/s
Proper motion (μ)	RA: +80.50[2] mas/yr Dec.: +14.64[2] mas/yr
Parallax (π)	14.04 ± 0.32 mas[2]
Distance	232 ± 5 ly (71 ± 2 pc)
Absolute magnitude (MV)	+1.24[6]
Details[4]
A
Mass	1.95 M☉
Radius	2.0 R☉
Luminosity	25.7[7] L☉
Surface gravity (log g)	4.02±0.14[8] cgs
Temperature	8,470 K
Rotational velocity (v sin i)	82.1±1.2[9] km/s
Age	560 Myr
B
Mass	0.72 M☉
Radius	0.67 R☉
Temperature	4,530 K
Other designations
σ Scl,  Sculptoris, CD−32° 410, HD 6178, HIP 4852, HR 293, SAO 192884[10]
Database references
SIMBAD	data

Sigma Sculptoris, Latinized from σ Sculptoris, is a binary star in the southern constellation of Sculptor. It is faintly visible to the naked eye with an apparent visual magnitude of +5.54.[3] Based upon an annual parallax shift of 14.04 mas as seen from Earth,[2] it is located about 232 light years from the Sun.

The main component is an main sequence A-type star with a stellar classification of A1/A2 IV.[11] It was suspected to be an Ap star and an Alpha2 Canum Venaticorum variable,[12] but no chemical peculiarity or variability was found in 2018.[4] The star has an estimated 1.95 the mass of the Sun and around two times the Sun's radius.[4] It is spinning with a projected rotational velocity of 82 km/s[9] and is about 560 million years old.[4] Sigma Sculptoris radiates 25.7[7] times the solar luminosity from its photosphere at an effective temperature of 8,470 K.[4]

The secondary is a small star with 72% the mass of the Sun, 5.7 times fainter than the primary.[4]

References

1. Manfroid, J.; Renson, P. (January 1994). "Photometric variations of AP stars". Astronomy and Astrophysics. 281: 73–89. Bibcode:1994A&A...281...73M. Retrieved 20 September 2024.
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. Westerlund, B. E. (1963), "Three-colour photometry of early-type stars near the galactic poles", Monthly Notices of the Royal Astronomical Society, 127 (1): 83, Bibcode:1963MNRAS.127...83W, doi:10.1093/mnras/127.1.83.
4. Waisberg, Idel; Klein, Ygal; Katz, Boaz (April 2024). "Hidden Companions to Intermediate-mass Stars. XVII. Uncovering a 0.72 M⊙, 0.35 au Companion in the Spectroscopic Binary Sigma Sculptoris*". Research Notes of the AAS. 8 (4): 101. doi:10.3847/2515-5172/ad3de9. ISSN 2515-5172.
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. 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.
8. 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.
9. Díaz, C. G.; et al. (July 2011), "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum", Astronomy & Astrophysics, 531: A143, arXiv:1012.4858, Bibcode:2011A&A...531A.143D, doi:10.1051/0004-6361/201016386, S2CID 119286673.
10. "sig Scl -- Variable Star of alpha2 CVn type", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-04-13.
11. Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
12. Samus, N. N.; Durlevich, O. V.; et al. (2009). "General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/gcvs. 1. Bibcode:2009yCat....102025S.