Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Corvus |
Right ascension | 12h 34m 23.23484s [1] |
Declination | −23° 23′ 48.3374″ [1] |
Apparent magnitude (V) | 2.647 [2] |
Characteristics | |
Spectral type | G5 II [3] |
U−B color index | +0.586 [2] |
B−V color index | +0.898 [2] |
R−I color index | +0.44 [4] |
Astrometry | |
Radial velocity (Rv) | −7.6 [5] km/s |
Proper motion (μ) |
RA: +1.11
[1]
mas/
yr Dec.: −56.56 [1] mas/ yr |
Parallax (π) | 22.39 ± 0.18 mas [1] |
Distance | 146 ± 1
ly (44.7 ± 0.4 pc) |
Absolute magnitude (MV) | –0.61 [6] |
Details | |
Mass | 3.342±0.077 [7] M☉ |
Radius | 15.841±0.72 [7] R☉ |
Luminosity | 164 [8] L☉ |
Surface gravity (log g) | 2.86 [7] cgs |
Temperature | 5,354 [7] K |
Metallicity [Fe/H] | 0.12±0.03 [7] dex |
Rotational velocity (v sin i) | 8 [9] km/s |
Age | 294±18 [7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Beta Corvi or β Corvi, officially named Kraz ( /ˈkræz/), [11] is the second-brightest star in the southern constellation of Corvus with an apparent visual magnitude of 2.647. [2] Based on parallax measurements obtained during the Hipparcos mission, it is about 146 light-years (45 parsecs) distant from the Sun.
β Corvi ( Latinised to Beta Corvi) is the star's Bayer designation.
In a 1951 publication, Atlas Coeli ( Skalnate Pleso Atlas of the Heavens) by Czech astronomer Antonín Bečvář, it bore the name Kraz, whose origin and meaning remain unknown. [12] [13] [14] In 2016, the IAU organized a Working Group on Star Names (WGSN) [15] to catalog and standardize proper names for stars. The WGSN approved the name Kraz for this star on 1 June 2018 and it is now so included in the List of IAU-approved Star Names. [11]
In Chinese, 軫宿 (Zhěn Sù), meaning Chariot (asterism), refers to an asterism consisting of Beta, Gamma, Epsilon and Delta Corvi. [16] Consequently, Beta Corvi itself is known as 軫宿四 (Zhěn Sù sì, English: the Fourth Star of Chariot). [17]
Beta Corvi has about 3.3 times the Sun's mass and is roughly 300 million years old, [7] which is old enough for a star of this mass to consume the hydrogen at its core and evolve away from the main sequence. The stellar classification is G5 II, [3] with the luminosity class of 'II' indicating this is a bright giant. The effective temperature of the star's outer envelope is about 5,350 K, [7] which produces a yellow hue common to G-type stars. [18]
Currently, Beta Corvi has expanded to 15.8 times the Sun's size [7] and is emitting about 164 times the luminosity of the Sun. [8] The abundance of elements other than hydrogen or helium, what astronomers term metallicity, is 1.32 times that of the Sun. [7] [a]
This is a variable star that ranges in apparent visual magnitude from a low of 2.66 to a high of 2.60. [19]
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Corvus |
Right ascension | 12h 34m 23.23484s [1] |
Declination | −23° 23′ 48.3374″ [1] |
Apparent magnitude (V) | 2.647 [2] |
Characteristics | |
Spectral type | G5 II [3] |
U−B color index | +0.586 [2] |
B−V color index | +0.898 [2] |
R−I color index | +0.44 [4] |
Astrometry | |
Radial velocity (Rv) | −7.6 [5] km/s |
Proper motion (μ) |
RA: +1.11
[1]
mas/
yr Dec.: −56.56 [1] mas/ yr |
Parallax (π) | 22.39 ± 0.18 mas [1] |
Distance | 146 ± 1
ly (44.7 ± 0.4 pc) |
Absolute magnitude (MV) | –0.61 [6] |
Details | |
Mass | 3.342±0.077 [7] M☉ |
Radius | 15.841±0.72 [7] R☉ |
Luminosity | 164 [8] L☉ |
Surface gravity (log g) | 2.86 [7] cgs |
Temperature | 5,354 [7] K |
Metallicity [Fe/H] | 0.12±0.03 [7] dex |
Rotational velocity (v sin i) | 8 [9] km/s |
Age | 294±18 [7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Beta Corvi or β Corvi, officially named Kraz ( /ˈkræz/), [11] is the second-brightest star in the southern constellation of Corvus with an apparent visual magnitude of 2.647. [2] Based on parallax measurements obtained during the Hipparcos mission, it is about 146 light-years (45 parsecs) distant from the Sun.
β Corvi ( Latinised to Beta Corvi) is the star's Bayer designation.
In a 1951 publication, Atlas Coeli ( Skalnate Pleso Atlas of the Heavens) by Czech astronomer Antonín Bečvář, it bore the name Kraz, whose origin and meaning remain unknown. [12] [13] [14] In 2016, the IAU organized a Working Group on Star Names (WGSN) [15] to catalog and standardize proper names for stars. The WGSN approved the name Kraz for this star on 1 June 2018 and it is now so included in the List of IAU-approved Star Names. [11]
In Chinese, 軫宿 (Zhěn Sù), meaning Chariot (asterism), refers to an asterism consisting of Beta, Gamma, Epsilon and Delta Corvi. [16] Consequently, Beta Corvi itself is known as 軫宿四 (Zhěn Sù sì, English: the Fourth Star of Chariot). [17]
Beta Corvi has about 3.3 times the Sun's mass and is roughly 300 million years old, [7] which is old enough for a star of this mass to consume the hydrogen at its core and evolve away from the main sequence. The stellar classification is G5 II, [3] with the luminosity class of 'II' indicating this is a bright giant. The effective temperature of the star's outer envelope is about 5,350 K, [7] which produces a yellow hue common to G-type stars. [18]
Currently, Beta Corvi has expanded to 15.8 times the Sun's size [7] and is emitting about 164 times the luminosity of the Sun. [8] The abundance of elements other than hydrogen or helium, what astronomers term metallicity, is 1.32 times that of the Sun. [7] [a]
This is a variable star that ranges in apparent visual magnitude from a low of 2.66 to a high of 2.60. [19]