Lambda1 Sculptoris

For other star systems with this Bayer designation, see λ Sculptoris.

Lambda¹ Sculptoris, Latinised 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	00h 42m 42.89190s[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 mas[1]
Distance	approx. 470 ly (approx. 150 pc)
Absolute magnitude (MV)	+0.27[7]
Details
λ1 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
λ1 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 arcsecond 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] The mass ratio is 0.609, meaning the secondary is only 60.9% as massive as the primary.^[11]