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Star in the constellation Sagitta
Zeta Sagittae
Location of ζ Sagittae (circled)
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
ζ Sge ,
8 Sge ,
BD +19°4229 ,
GC 27431,
HD 187362,
HIP 97496,
HR 7546,
SAO 105298,
PPM 137034,
ADS 12973,
WDS J19490+1909AB
[12]
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]
Naming
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]
References
^
a
b
c
d
e
f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics , 474 (2): 653–664,
arXiv :
0708.1752 ,
Bibcode :
2007A&A...474..653V ,
doi :
10.1051/0004-6361:20078357 ,
S2CID
18759600 .
^
a
b
c
d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory , 4 (99): 99,
Bibcode :
1966CoLPL...4...99J .
^
a
b
c
d Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society , 389 (2): 869–879,
arXiv :
0806.2878 ,
Bibcode :
2008MNRAS.389..869E ,
doi :
10.1111/j.1365-2966.2008.13596.x ,
S2CID
14878976 .
^
a
b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal , 74 : 375–406,
Bibcode :
1969AJ.....74..375C ,
doi :
10.1086/110819 .
^ Christy, James W.; Walker, R. L. Jr. (October 1969), "MK Classification of 142 Visual Binaries", Publications of the Astronomical Society of the Pacific , 81 (482): 643,
Bibcode :
1969PASP...81..643C ,
doi :
10.1086/128831 .
^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters , 38 (5): 331,
arXiv :
1108.4971 ,
Bibcode :
2012AstL...38..331A ,
doi :
10.1134/S1063773712050015 ,
S2CID
119257644 .
^
a
b Muterspaugh, Matthew W.; et al. (December 2010), "The Phases Differential Astrometry Data Archive. II. Updated Binary Star Orbits and a Long Period Eclipsing Binary", The Astronomical Journal , 140 (6): 1623–1630,
arXiv :
1010.4043 ,
Bibcode :
2010AJ....140.1623M ,
doi :
10.1088/0004-6256/140/6/1623 ,
S2CID
6030289 .
^
a
b
c
d David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal , 804 (2): 146,
arXiv :
1501.03154 ,
Bibcode :
2015ApJ...804..146D ,
doi :
10.1088/0004-637X/804/2/146 ,
S2CID
33401607 .
^ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics , 367 (Third ed.): 521–524,
arXiv :
astro-ph/0012289 ,
Bibcode :
2001A&A...367..521P ,
doi :
10.1051/0004-6361:20000451 ,
S2CID
425754 .
^ McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society , 427 (1): 343–57,
arXiv :
1208.2037 ,
Bibcode :
2012MNRAS.427..343M ,
doi :
10.1111/j.1365-2966.2012.21873.x ,
S2CID
118665352 .
^
a
b Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review , 20 (1): 51,
arXiv :
1204.2572 ,
Bibcode :
2012A&ARv..20...51V ,
doi :
10.1007/s00159-012-0051-2 ,
S2CID
119273474 .
^
"zet Sge" .
SIMBAD .
Centre de données astronomiques de Strasbourg . Retrieved 2017-07-11 .
^ (in Chinese)
AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 3 日
External links
Kaler, James B. (August 3, 2012),
"Zeta Sagittae" , stars , University of Illinois, retrieved 2017-07-13 .