Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Lupus |
Right ascension | 15h 35m 53.24806s [2] |
Declination | −44° 57′ 30.1982″ [2] |
Apparent magnitude (V) | 4.55 [3] (4.66 + 6.62) [4] |
Characteristics | |
Spectral type | B3 V + B6 V [5] |
B−V color index | −0.175±0.003 [3] |
Variable type | Be [6] |
Astrometry | |
Radial velocity (Rv) | +6.5±2.8 [7] km/s |
Proper motion (μ) |
RA: −20.53
[2]
mas/
yr Dec.: −21.23 [2] mas/ yr |
Parallax (π) | 7.62 ± 0.43 mas [2] |
Distance | 430 ± 20
ly (131 ± 7 pc) |
Absolute magnitude (MV) | −1.03 [3] |
Details | |
KT Lup A | |
Mass | 5.9±0.1 [8] M☉ |
Radius | 3.00±0.06 [9] R☉ |
Luminosity | 794+791 −396 [10] L☉ |
Surface gravity (log g) | 3.50±0.04 [9] cgs |
Temperature | 18,400±184 [9] K |
Rotational velocity (v sin i) | 30±0.6 [9] km/s |
Age | 21.0±10.6 [8] Myr |
KT Lup B | |
Mass | 2.79 [11] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
KT Lupi is a visual binary star [5] system in the constellation Lupus. It is visible to the naked eye with a combined apparent visual magnitude of 4.55. [3] As of 1983, the pair had an angular separation of 2.19 ″±0.03 ″. [10] Based upon an annual parallax shift of 7.6 mas [2] as seen from Earth's orbit, it is located 430 light-years from the Sun. The system is moving further from the Earth with a heliocentric radial velocity of +6.5 km/s. [7] It is a member of the Lower Centaurus–Crux sub-group of the Scorpius–Centaurus association. [5]
The primary, component A, is a variable Be star, [6] with the variation being modulated by rotation. [13] It is visual magnitude 4.66 [4] with a stellar classification of B3 V, [5] matching a B-type main-sequence star. Hiltner et al. (1969) gave a class of B3 IVp, [14] which is still used in some studies. [8] [9] [10] It is a helium-weak chemically peculiar star showing an enhanced silicon patch near the equator and a silicon-weak region close to the pole. [10] The star is about 21 million years old with nearly six [8] times the mass of the Sun and three times the Sun's radius. [9] It is radiating roughly 794 [10] times the Sun's luminosity from its photosphere at an effective temperature of 18,400 K. [9]
The secondary companion, component B, is of magnitude 6.62 [4] with a class of B6 V. [5] It has 2.79 times the Sun's mass. [11]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Lupus |
Right ascension | 15h 35m 53.24806s [2] |
Declination | −44° 57′ 30.1982″ [2] |
Apparent magnitude (V) | 4.55 [3] (4.66 + 6.62) [4] |
Characteristics | |
Spectral type | B3 V + B6 V [5] |
B−V color index | −0.175±0.003 [3] |
Variable type | Be [6] |
Astrometry | |
Radial velocity (Rv) | +6.5±2.8 [7] km/s |
Proper motion (μ) |
RA: −20.53
[2]
mas/
yr Dec.: −21.23 [2] mas/ yr |
Parallax (π) | 7.62 ± 0.43 mas [2] |
Distance | 430 ± 20
ly (131 ± 7 pc) |
Absolute magnitude (MV) | −1.03 [3] |
Details | |
KT Lup A | |
Mass | 5.9±0.1 [8] M☉ |
Radius | 3.00±0.06 [9] R☉ |
Luminosity | 794+791 −396 [10] L☉ |
Surface gravity (log g) | 3.50±0.04 [9] cgs |
Temperature | 18,400±184 [9] K |
Rotational velocity (v sin i) | 30±0.6 [9] km/s |
Age | 21.0±10.6 [8] Myr |
KT Lup B | |
Mass | 2.79 [11] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
KT Lupi is a visual binary star [5] system in the constellation Lupus. It is visible to the naked eye with a combined apparent visual magnitude of 4.55. [3] As of 1983, the pair had an angular separation of 2.19 ″±0.03 ″. [10] Based upon an annual parallax shift of 7.6 mas [2] as seen from Earth's orbit, it is located 430 light-years from the Sun. The system is moving further from the Earth with a heliocentric radial velocity of +6.5 km/s. [7] It is a member of the Lower Centaurus–Crux sub-group of the Scorpius–Centaurus association. [5]
The primary, component A, is a variable Be star, [6] with the variation being modulated by rotation. [13] It is visual magnitude 4.66 [4] with a stellar classification of B3 V, [5] matching a B-type main-sequence star. Hiltner et al. (1969) gave a class of B3 IVp, [14] which is still used in some studies. [8] [9] [10] It is a helium-weak chemically peculiar star showing an enhanced silicon patch near the equator and a silicon-weak region close to the pole. [10] The star is about 21 million years old with nearly six [8] times the mass of the Sun and three times the Sun's radius. [9] It is radiating roughly 794 [10] times the Sun's luminosity from its photosphere at an effective temperature of 18,400 K. [9]
The secondary companion, component B, is of magnitude 6.62 [4] with a class of B6 V. [5] It has 2.79 times the Sun's mass. [11]