Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Pegasus |
Right ascension | 23h 25m 22.78350s [1] |
Declination | +23° 24′ 14.7606″ [1] |
Apparent magnitude (V) | 4.40 [2] |
Characteristics | |
Evolutionary stage | Hertzsprung gap [3] |
Spectral type | F8III [4] |
U−B color index | +0.14 [2] |
B−V color index | +0.61 [2] |
Astrometry | |
Radial velocity (Rv) | −8.59 [5] km/s |
Proper motion (μ) |
RA: +192.19
[1]
mas/
yr Dec.: +36.12 [1] mas/ yr |
Parallax (π) | 19.14 ± 0.18 mas [1] |
Distance | 170 ± 2
ly (52.2 ± 0.5 pc) |
Absolute magnitude (MV) | 0.83 [6] |
Details | |
Mass | 2.17 [7] M☉ |
Radius | 5.97+0.36 −0.19 [8] R☉ |
Luminosity | 43.2±0.8 [8] L☉ |
Surface gravity (log g) | 3.22 [7] cgs |
Temperature | 6,061+97 −176 [8] K |
Metallicity [Fe/H] | −0.01 [6] dex |
Rotational velocity (v sin i) | 73.4 [3] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Upsilon Pegasi, Latinised from υ Pegasi, is a star within the great square [10] in the northern constellation of Pegasus. It has the proper name Alkarab /ˈælkəræb/. [11] This object has a yellow-white hue and is faintly visible to the naked eye with an apparent magnitude of 4.40. [2] It is located at a distance of approximately 170 light-years from the Sun based on parallax, [1] but is drifting closer with a radial velocity of −8.6 km/s. [5] The star is moving through the galaxy at a speed of 50.6 km/s relative to the Sun. Its projected galactic orbit carries it between 18,600 and 26,300 light-years from the center of the galaxy. [6]
This object is an aging giant star with a stellar classification of F8III. [4] It is currently in the Hertzsprung gap and is a source of X-ray emission. [3] The star has 2.2 [7] times the mass of the Sun and is spinning with a projected rotational velocity of 73.4 km/s. [3] It has an iron abundance of −0.01 dex, or 97.7% of the Sun's. Upsilon Pegasi has six times the girth of the Sun and is radiating 43 times the Sun's luminosity at an effective temperature of 6,061 K. [8]
υ Pegasi is the star's Bayer designation. The star bore the traditional Arabic name Al Karab ("the Bucket-rope"). [12] In 2016, the IAU organized a Working Group on Star Names (WGSN) [13] to catalog and standardize proper names for stars. The WGSN approved the name Alkarab for this star on 5 September 2017 and it is now so included in the List of IAU-approved Star Names. [11]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Pegasus |
Right ascension | 23h 25m 22.78350s [1] |
Declination | +23° 24′ 14.7606″ [1] |
Apparent magnitude (V) | 4.40 [2] |
Characteristics | |
Evolutionary stage | Hertzsprung gap [3] |
Spectral type | F8III [4] |
U−B color index | +0.14 [2] |
B−V color index | +0.61 [2] |
Astrometry | |
Radial velocity (Rv) | −8.59 [5] km/s |
Proper motion (μ) |
RA: +192.19
[1]
mas/
yr Dec.: +36.12 [1] mas/ yr |
Parallax (π) | 19.14 ± 0.18 mas [1] |
Distance | 170 ± 2
ly (52.2 ± 0.5 pc) |
Absolute magnitude (MV) | 0.83 [6] |
Details | |
Mass | 2.17 [7] M☉ |
Radius | 5.97+0.36 −0.19 [8] R☉ |
Luminosity | 43.2±0.8 [8] L☉ |
Surface gravity (log g) | 3.22 [7] cgs |
Temperature | 6,061+97 −176 [8] K |
Metallicity [Fe/H] | −0.01 [6] dex |
Rotational velocity (v sin i) | 73.4 [3] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Upsilon Pegasi, Latinised from υ Pegasi, is a star within the great square [10] in the northern constellation of Pegasus. It has the proper name Alkarab /ˈælkəræb/. [11] This object has a yellow-white hue and is faintly visible to the naked eye with an apparent magnitude of 4.40. [2] It is located at a distance of approximately 170 light-years from the Sun based on parallax, [1] but is drifting closer with a radial velocity of −8.6 km/s. [5] The star is moving through the galaxy at a speed of 50.6 km/s relative to the Sun. Its projected galactic orbit carries it between 18,600 and 26,300 light-years from the center of the galaxy. [6]
This object is an aging giant star with a stellar classification of F8III. [4] It is currently in the Hertzsprung gap and is a source of X-ray emission. [3] The star has 2.2 [7] times the mass of the Sun and is spinning with a projected rotational velocity of 73.4 km/s. [3] It has an iron abundance of −0.01 dex, or 97.7% of the Sun's. Upsilon Pegasi has six times the girth of the Sun and is radiating 43 times the Sun's luminosity at an effective temperature of 6,061 K. [8]
υ Pegasi is the star's Bayer designation. The star bore the traditional Arabic name Al Karab ("the Bucket-rope"). [12] In 2016, the IAU organized a Working Group on Star Names (WGSN) [13] to catalog and standardize proper names for stars. The WGSN approved the name Alkarab for this star on 5 September 2017 and it is now so included in the List of IAU-approved Star Names. [11]