Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquarius |
Right ascension | 21h 39m 33.26758s [1] |
Declination | +02° 14′ 36.8173″ [1] |
Apparent magnitude (V) | +5.09 [2] |
Characteristics | |
Spectral type | K0 III [3] |
U−B color index | +0.90 [2] |
B−V color index | +1.032 [4] |
Astrometry | |
Radial velocity (Rv) | –34.63 ± 0.11 [4] km/s |
Proper motion (μ) |
RA: –29.55
[1]
mas/
yr Dec.: –83.22 [1] mas/ yr |
Parallax (π) | 14.40 ± 0.30 mas [1] |
Distance | 226 ± 5
ly (69 ± 1 pc) |
Details | |
Radius | 11 [4] R☉ |
Luminosity | 54 [4] L☉ |
Surface gravity (log g) | 2.5 [4] cgs |
Temperature | 4,721 [4] K |
Metallicity [Fe/H] | –0.17 [4] dex |
Rotational velocity (v sin i) | 2.5 [4] km/s |
Other designations | |
Database references | |
SIMBAD | data |
25 Aquarii (abbreviated 25 Aqr) is a single [3] star in the equatorial constellation of Aquarius. 25 Aquarii is the modern Flamsteed designation; in the past it held the designation 6 Pegasi. [6] It also bears the Bayer designation of d Aquarii. It is located near the border with the modern Pegasus constellation. Although faint at an apparent visual magnitude of +5.09, [2] it is bright enough to be viewed from suburban skies. Based upon an annual parallax shift of 0.01440 arcseconds, [1] it is located at a distance of around 226 light-years (69 parsecs) from Earth. The visual magnitude of the star is diminished by 0.09 from extinction caused by intervening gas and dust. [7]
The spectrum of this star matches a stellar classification of K0 III, [3] with the luminosity class of III indicating that this is a giant star that has evolved away from the main sequence after exhausting the supply of hydrogen at its core. It belongs to a population known as clump giants and hence is generating energy through the nuclear fusion of helium at the core. [8] The outer envelope has expanded to 11 times the radius of the Sun and it is radiating 54 times the Sun's luminosity. [4] This energy is being emitted from the stellar atmosphere at an effective temperature of 4,721 K, [4] causing it to glow with the orange hue of a K-type star. [9]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquarius |
Right ascension | 21h 39m 33.26758s [1] |
Declination | +02° 14′ 36.8173″ [1] |
Apparent magnitude (V) | +5.09 [2] |
Characteristics | |
Spectral type | K0 III [3] |
U−B color index | +0.90 [2] |
B−V color index | +1.032 [4] |
Astrometry | |
Radial velocity (Rv) | –34.63 ± 0.11 [4] km/s |
Proper motion (μ) |
RA: –29.55
[1]
mas/
yr Dec.: –83.22 [1] mas/ yr |
Parallax (π) | 14.40 ± 0.30 mas [1] |
Distance | 226 ± 5
ly (69 ± 1 pc) |
Details | |
Radius | 11 [4] R☉ |
Luminosity | 54 [4] L☉ |
Surface gravity (log g) | 2.5 [4] cgs |
Temperature | 4,721 [4] K |
Metallicity [Fe/H] | –0.17 [4] dex |
Rotational velocity (v sin i) | 2.5 [4] km/s |
Other designations | |
Database references | |
SIMBAD | data |
25 Aquarii (abbreviated 25 Aqr) is a single [3] star in the equatorial constellation of Aquarius. 25 Aquarii is the modern Flamsteed designation; in the past it held the designation 6 Pegasi. [6] It also bears the Bayer designation of d Aquarii. It is located near the border with the modern Pegasus constellation. Although faint at an apparent visual magnitude of +5.09, [2] it is bright enough to be viewed from suburban skies. Based upon an annual parallax shift of 0.01440 arcseconds, [1] it is located at a distance of around 226 light-years (69 parsecs) from Earth. The visual magnitude of the star is diminished by 0.09 from extinction caused by intervening gas and dust. [7]
The spectrum of this star matches a stellar classification of K0 III, [3] with the luminosity class of III indicating that this is a giant star that has evolved away from the main sequence after exhausting the supply of hydrogen at its core. It belongs to a population known as clump giants and hence is generating energy through the nuclear fusion of helium at the core. [8] The outer envelope has expanded to 11 times the radius of the Sun and it is radiating 54 times the Sun's luminosity. [4] This energy is being emitted from the stellar atmosphere at an effective temperature of 4,721 K, [4] causing it to glow with the orange hue of a K-type star. [9]