Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Libra |
Right ascension | 15h 00m 58.34830s [2] |
Declination | −08° 31′ 08.2104″ [2] |
Apparent magnitude (V) | 4.93 [3] |
Characteristics | |
Spectral type | B9.5V [4] |
U−B color index | –0.10 [5] |
B−V color index | +0.00 [5] |
Variable type | Eclipsing binary of Algol type (EA/SD) [6] |
Astrometry | |
Radial velocity (Rv) | −38.7±2 [7] km/s |
Proper motion (μ) |
RA: −63.051
[2]
mas/
yr Dec.: −6.024 [2] mas/ yr |
Parallax (π) | 9.2824 ± 0.4725 mas [2] |
Distance | 350 ± 20
ly (108 ± 5 pc) |
Absolute magnitude (MV) | +0.15 [8] |
Orbit [9] | |
Period (P) | 2.3274 d |
Eccentricity (e) | 0.07 |
Semi-amplitude (K1) (primary) | 76.6 km/s |
Semi-amplitude (K2) (secondary) | 218.7 km/s |
Details | |
δ Lib A | |
Mass | 4.9±0.2 [9] M☉ |
Radius | 3.94 [10] R☉ |
Luminosity | 86 [8] L☉ |
Temperature | 8800 [10] K |
Age | 0.5 [10] Gyr |
δ Lib B | |
Mass | 1.7±0.2 [9] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
Delta Librae, Latinized from δ Librae, is a variable star in the constellation Libra. It has the traditional name Zuben Elakribi, a variant of the traditional name of Gamma Librae. [11] With μ Virginis it forms one of the Akkadian lunar mansions Mulu-izi [12](meaning "Man-of-fire" [13]).
δ Librae is approximately 300 light years from the Earth and the primary, component A, belongs to the spectral class B9.5V, indicating it is a B-type main-sequence star. It is visible to the naked eye with an apparent visual magnitude of 4.93 [3] and is moving closer to the Sun with a radial velocity of −39 km/s. [7] This is an Algol-like eclipsing binary star system, with a period of 2.3274 days and an eccentricity of 0.07. [9] Its apparent magnitude varies from 4.91m to 5.9m. [14] The secondary is filling its Roche lobe and there is evidence of large-scale mass transfer in the past, with the star being more evolved than the primary. [9]
Along with λ Tauri, it was one of the first stars on which rotational line broadening [15] was observed, by Frank Schlesinger in 1911.
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Libra |
Right ascension | 15h 00m 58.34830s [2] |
Declination | −08° 31′ 08.2104″ [2] |
Apparent magnitude (V) | 4.93 [3] |
Characteristics | |
Spectral type | B9.5V [4] |
U−B color index | –0.10 [5] |
B−V color index | +0.00 [5] |
Variable type | Eclipsing binary of Algol type (EA/SD) [6] |
Astrometry | |
Radial velocity (Rv) | −38.7±2 [7] km/s |
Proper motion (μ) |
RA: −63.051
[2]
mas/
yr Dec.: −6.024 [2] mas/ yr |
Parallax (π) | 9.2824 ± 0.4725 mas [2] |
Distance | 350 ± 20
ly (108 ± 5 pc) |
Absolute magnitude (MV) | +0.15 [8] |
Orbit [9] | |
Period (P) | 2.3274 d |
Eccentricity (e) | 0.07 |
Semi-amplitude (K1) (primary) | 76.6 km/s |
Semi-amplitude (K2) (secondary) | 218.7 km/s |
Details | |
δ Lib A | |
Mass | 4.9±0.2 [9] M☉ |
Radius | 3.94 [10] R☉ |
Luminosity | 86 [8] L☉ |
Temperature | 8800 [10] K |
Age | 0.5 [10] Gyr |
δ Lib B | |
Mass | 1.7±0.2 [9] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
Delta Librae, Latinized from δ Librae, is a variable star in the constellation Libra. It has the traditional name Zuben Elakribi, a variant of the traditional name of Gamma Librae. [11] With μ Virginis it forms one of the Akkadian lunar mansions Mulu-izi [12](meaning "Man-of-fire" [13]).
δ Librae is approximately 300 light years from the Earth and the primary, component A, belongs to the spectral class B9.5V, indicating it is a B-type main-sequence star. It is visible to the naked eye with an apparent visual magnitude of 4.93 [3] and is moving closer to the Sun with a radial velocity of −39 km/s. [7] This is an Algol-like eclipsing binary star system, with a period of 2.3274 days and an eccentricity of 0.07. [9] Its apparent magnitude varies from 4.91m to 5.9m. [14] The secondary is filling its Roche lobe and there is evidence of large-scale mass transfer in the past, with the star being more evolved than the primary. [9]
Along with λ Tauri, it was one of the first stars on which rotational line broadening [15] was observed, by Frank Schlesinger in 1911.