Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Sagittarius |
Right ascension | 18h 55m 07.14098s [1] |
Declination | −22° 40′ 16.8185″ [1] |
Apparent magnitude (V) | +4.98 [2] |
Characteristics | |
Spectral type | K1 Ib–II [3] |
B−V color index | +1.32 [2] |
Astrometry | |
Radial velocity (Rv) | −109.6 [2] km/s |
Proper motion (μ) |
RA: −109.04
[1]
mas/
yr Dec.: −35.25 [1] mas/ yr |
Parallax (π) | 11.91 ± 0.52 mas [1] |
Distance | 270 ± 10
ly (84 ± 4 pc) |
Absolute magnitude (MV) | +0.38 [4] |
Details | |
ν2 Sgr A | |
Mass | 1.44 [2] M☉ |
Radius | 85 [5] R☉ |
Luminosity | 120 [2] L☉ |
Surface gravity (log g) | 1.03 [6] cgs |
Temperature | 4,244±57 [2] K |
Metallicity [Fe/H] | −0.13 [6] dex |
Age | 4.52 [2] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Nu2 Sagittarii (ν2 Sagittarii) is a
binary star
[8] system in the
zodiac constellation of
Sagittarius. It is faintly visible to the naked eye, having an
apparent visual magnitude of +4.98;
[2] it is 0.16 degree north of the
ecliptic. The annual
parallax shift of 11.91
mas as seen from Earth,
[1] indicates this system is roughly 270
light years from the
Sun. Nu2 Sagittarii has a high
peculiar velocity of 86.0+11.6
−14.4 km/s and is most likely a
runaway star system.
[3]
The spectrum of the primary component displays a stellar classification of K1 Ib–II, [3] indicating this is a K-type star with a mixed luminosity class of an evolved bright giant/ supergiant star. It is a mild barium star, showing an enhanced abundance of s-process elements in its outer atmosphere. This material was most likely acquired during a previous mass transfer from its now white dwarf companion. [9] The primary has an estimated 1.4 [2] times the mass of the Sun and has expanded to 85 [5] times the Sun's radius.
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Sagittarius |
Right ascension | 18h 55m 07.14098s [1] |
Declination | −22° 40′ 16.8185″ [1] |
Apparent magnitude (V) | +4.98 [2] |
Characteristics | |
Spectral type | K1 Ib–II [3] |
B−V color index | +1.32 [2] |
Astrometry | |
Radial velocity (Rv) | −109.6 [2] km/s |
Proper motion (μ) |
RA: −109.04
[1]
mas/
yr Dec.: −35.25 [1] mas/ yr |
Parallax (π) | 11.91 ± 0.52 mas [1] |
Distance | 270 ± 10
ly (84 ± 4 pc) |
Absolute magnitude (MV) | +0.38 [4] |
Details | |
ν2 Sgr A | |
Mass | 1.44 [2] M☉ |
Radius | 85 [5] R☉ |
Luminosity | 120 [2] L☉ |
Surface gravity (log g) | 1.03 [6] cgs |
Temperature | 4,244±57 [2] K |
Metallicity [Fe/H] | −0.13 [6] dex |
Age | 4.52 [2] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Nu2 Sagittarii (ν2 Sagittarii) is a
binary star
[8] system in the
zodiac constellation of
Sagittarius. It is faintly visible to the naked eye, having an
apparent visual magnitude of +4.98;
[2] it is 0.16 degree north of the
ecliptic. The annual
parallax shift of 11.91
mas as seen from Earth,
[1] indicates this system is roughly 270
light years from the
Sun. Nu2 Sagittarii has a high
peculiar velocity of 86.0+11.6
−14.4 km/s and is most likely a
runaway star system.
[3]
The spectrum of the primary component displays a stellar classification of K1 Ib–II, [3] indicating this is a K-type star with a mixed luminosity class of an evolved bright giant/ supergiant star. It is a mild barium star, showing an enhanced abundance of s-process elements in its outer atmosphere. This material was most likely acquired during a previous mass transfer from its now white dwarf companion. [9] The primary has an estimated 1.4 [2] times the mass of the Sun and has expanded to 85 [5] times the Sun's radius.