Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Sagitta |
Right ascension | 19h 48m 58.65978s [1] |
Declination | +19° 08′ 31.3516″ [1] |
Apparent magnitude (V) | +5.00 [2] (5.64 + 6.04 + 9.01) [3] |
Characteristics | |
Spectral type | A3 Vnn [4] (A1 V + A3 V) [5] |
U−B color index | +0.06 [2] |
B−V color index | +0.10 [2] |
Astrometry | |
Proper motion (μ) |
RA: +17.63
[1]
mas/
yr Dec.: +26.27 [1] mas/ yr |
Parallax (π) | 12.79 ± 0.67 mas [1] |
Distance | 260 ± 10
ly (78 ± 4 pc) |
Absolute magnitude (MV) | +0.55 [6] |
Orbit [7] | |
Period (P) | 8487.9±4.9 d |
Semi-major axis (a) | 0.13605±0.00044″ |
Eccentricity (e) | 0.7948±0.0019 |
Inclination (i) | 132.33±0.41° |
Longitude of the node (Ω) | 340.97±0.68° |
Periastron epoch (T) | 44199.6±5.9 HMJD |
Argument of periastron (ω) (secondary) | 355.3±1.0° |
Details | |
ζ Sge A | |
Mass | 1.80 [8] M☉ |
Radius | 1.7 [9] R☉ |
Luminosity | 46 [10] L☉ |
Surface gravity (log g) | 3.89 [8] cgs |
Temperature | 8,422±286 [8] K |
Rotational velocity (v sin i) | 240 [11] km/s |
Age | 347 [8] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Zeta Sagittae (ζ Sagittae) is triple star [3] system in the northern constellation of Sagitta. It is visible to the naked eye, having a combined apparent visual magnitude of +5.00. [2] Based upon an annual parallax shift of 12.79 mas, [1] the distance to this star is approximately 260 light years.
The inner pair is a visual binary system consisting of two A-type main-sequence stars with an orbital period of 23.2 years (8,487.9 d), a semimajor axis of 0.136 arc seconds, and an eccentricity of 0.79. [7] The primary, component A, has a visual magnitude of 5.64 [3] with a stellar classification of A3 Vnn, [4] where the 'nn' suffix indicates "nebulous" lines due to rotation. It is spinning rapidly with a projected rotational velocity of 240 km/s. This is giving the star an oblate shape with an equatorial bulge that is 14% larger than the polar radius. [11]
The secondary member, component B, is a magnitude 6.04 star, while the more distant component C is magnitude 9.01 and lies at an angular separation of 8.330 arc seconds from the other two. [3]
In Chinese, 左旗 (Zuǒ Qí), meaning Left Flag, refers to an asterism consisting of ζ Sagittae, α Sagittae, β Sagittae, δ Sagittae, γ Sagittae, 13 Sagittae, 11 Sagittae, 14 Sagittae and ρ Aquilae. Consequently, the Chinese name for ζ Sagittae itself is 左旗四 (Zuǒ Qí sì, English: the Fourth Star of Left Flag.) [13]
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Sagitta |
Right ascension | 19h 48m 58.65978s [1] |
Declination | +19° 08′ 31.3516″ [1] |
Apparent magnitude (V) | +5.00 [2] (5.64 + 6.04 + 9.01) [3] |
Characteristics | |
Spectral type | A3 Vnn [4] (A1 V + A3 V) [5] |
U−B color index | +0.06 [2] |
B−V color index | +0.10 [2] |
Astrometry | |
Proper motion (μ) |
RA: +17.63
[1]
mas/
yr Dec.: +26.27 [1] mas/ yr |
Parallax (π) | 12.79 ± 0.67 mas [1] |
Distance | 260 ± 10
ly (78 ± 4 pc) |
Absolute magnitude (MV) | +0.55 [6] |
Orbit [7] | |
Period (P) | 8487.9±4.9 d |
Semi-major axis (a) | 0.13605±0.00044″ |
Eccentricity (e) | 0.7948±0.0019 |
Inclination (i) | 132.33±0.41° |
Longitude of the node (Ω) | 340.97±0.68° |
Periastron epoch (T) | 44199.6±5.9 HMJD |
Argument of periastron (ω) (secondary) | 355.3±1.0° |
Details | |
ζ Sge A | |
Mass | 1.80 [8] M☉ |
Radius | 1.7 [9] R☉ |
Luminosity | 46 [10] L☉ |
Surface gravity (log g) | 3.89 [8] cgs |
Temperature | 8,422±286 [8] K |
Rotational velocity (v sin i) | 240 [11] km/s |
Age | 347 [8] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Zeta Sagittae (ζ Sagittae) is triple star [3] system in the northern constellation of Sagitta. It is visible to the naked eye, having a combined apparent visual magnitude of +5.00. [2] Based upon an annual parallax shift of 12.79 mas, [1] the distance to this star is approximately 260 light years.
The inner pair is a visual binary system consisting of two A-type main-sequence stars with an orbital period of 23.2 years (8,487.9 d), a semimajor axis of 0.136 arc seconds, and an eccentricity of 0.79. [7] The primary, component A, has a visual magnitude of 5.64 [3] with a stellar classification of A3 Vnn, [4] where the 'nn' suffix indicates "nebulous" lines due to rotation. It is spinning rapidly with a projected rotational velocity of 240 km/s. This is giving the star an oblate shape with an equatorial bulge that is 14% larger than the polar radius. [11]
The secondary member, component B, is a magnitude 6.04 star, while the more distant component C is magnitude 9.01 and lies at an angular separation of 8.330 arc seconds from the other two. [3]
In Chinese, 左旗 (Zuǒ Qí), meaning Left Flag, refers to an asterism consisting of ζ Sagittae, α Sagittae, β Sagittae, δ Sagittae, γ Sagittae, 13 Sagittae, 11 Sagittae, 14 Sagittae and ρ Aquilae. Consequently, the Chinese name for ζ Sagittae itself is 左旗四 (Zuǒ Qí sì, English: the Fourth Star of Left Flag.) [13]