Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquarius |
Right ascension | 20h 56m 54.02626s [1] |
Declination | −09° 41′ 51.1610″ [1] |
Apparent magnitude (V) | 5.499 [2] (5.62 + 11.4) [3] |
Characteristics | |
Spectral type | K4 III [4] |
B−V color index | +1.474±0.006 [5] |
Variable type | Suspected [6] |
Astrometry | |
Radial velocity (Rv) | −32.4±1.6 [7] km/s |
Proper motion (μ) |
RA: −5.577
[1]
mas/
yr Dec.: −10.245 [1] mas/ yr |
Parallax (π) | 4.9495 ± 0.1309 mas [1] |
Distance | 660 ± 20
ly (202 ± 5 pc) |
Absolute magnitude (MV) | −0.61 [5] |
Details | |
Radius | 46 [8] R☉ |
Luminosity | 403.66 [5] L☉ |
Surface gravity (log g) | 1.650 [2] cgs |
Temperature | 3,990 [2] K |
Metallicity [Fe/H] | −0.17 [2] dex |
Other designations | |
Database references | |
SIMBAD | data |
7 Aquarii, abbreviated 7 Aqr, is a binary star [3] system in the zodiac constellation of Aquarius. 7 Aquarii is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 5.5; [2] the brighter component is baseline magnitude 5.62 while the faint secondary is magnitude 11.4. [3] As of 2002, the pair had an angular separation of 2.10 ″ along a position angle of 165°. [10] The distance to this system, based upon an annual parallax shift of 4.9 mas, [1] is around 660 light years. It is moving closer to the Earth with a heliocentric radial velocity of −32 km/s. [7]
The primary component is an aging giant star with a stellar classification of K4 III. [4] It is a suspected variable star of unknown type with a maximum magnitude of 5.48. [6] The interferometry-measured angular diameter of this star, after correcting for limb darkening, is 2.14±0.02 mas, [11] which, at its estimated distance, equates to a physical radius of about 46 times the radius of the Sun. [8] The star is radiating 404 [5] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,990 K. [2]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquarius |
Right ascension | 20h 56m 54.02626s [1] |
Declination | −09° 41′ 51.1610″ [1] |
Apparent magnitude (V) | 5.499 [2] (5.62 + 11.4) [3] |
Characteristics | |
Spectral type | K4 III [4] |
B−V color index | +1.474±0.006 [5] |
Variable type | Suspected [6] |
Astrometry | |
Radial velocity (Rv) | −32.4±1.6 [7] km/s |
Proper motion (μ) |
RA: −5.577
[1]
mas/
yr Dec.: −10.245 [1] mas/ yr |
Parallax (π) | 4.9495 ± 0.1309 mas [1] |
Distance | 660 ± 20
ly (202 ± 5 pc) |
Absolute magnitude (MV) | −0.61 [5] |
Details | |
Radius | 46 [8] R☉ |
Luminosity | 403.66 [5] L☉ |
Surface gravity (log g) | 1.650 [2] cgs |
Temperature | 3,990 [2] K |
Metallicity [Fe/H] | −0.17 [2] dex |
Other designations | |
Database references | |
SIMBAD | data |
7 Aquarii, abbreviated 7 Aqr, is a binary star [3] system in the zodiac constellation of Aquarius. 7 Aquarii is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 5.5; [2] the brighter component is baseline magnitude 5.62 while the faint secondary is magnitude 11.4. [3] As of 2002, the pair had an angular separation of 2.10 ″ along a position angle of 165°. [10] The distance to this system, based upon an annual parallax shift of 4.9 mas, [1] is around 660 light years. It is moving closer to the Earth with a heliocentric radial velocity of −32 km/s. [7]
The primary component is an aging giant star with a stellar classification of K4 III. [4] It is a suspected variable star of unknown type with a maximum magnitude of 5.48. [6] The interferometry-measured angular diameter of this star, after correcting for limb darkening, is 2.14±0.02 mas, [11] which, at its estimated distance, equates to a physical radius of about 46 times the radius of the Sun. [8] The star is radiating 404 [5] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,990 K. [2]