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Globular cluster in the constellation Delphinus
NGC 6934 (also known as Caldwell 47 ) is a
globular cluster of stars in the northern
constellation of
Delphinus , about 52
kilolight-years distant from the
Sun .
[3] It was discovered by the German-born astronomer
William Herschel on 24 September 1785.
[4] The cluster is following a highly eccentric orbit (with an
eccentricity of 0.81) through the
Milky Way along an
orbital plane that is inclined by 73° to the
galactic plane . It may share a common dynamic origin with
NGC 5466 .
[6] As of 2018, it has been poorly studied.
[9]
This appears to be a
Oosterhoff type I cluster with an intermediate
metallicity .
[10] It has an
Shapley–Sawyer Concentration Class of VIII,
[1] with a
core radius of 15″
[3] and a half-light radius of 36″ .
[5] The estimated mass is 295,000 times the
mass of the Sun .
[7] The cluster displays photometric anomalies, with a split
subgiant branch on the
HR diagram .
[9] Searches for
variable stars have discovered 85 in the cluster field, of which 79 are of the
RR Lyrae class and one is a
SX Phe variable .
[10] There is some evidence for a
tidal tail .
[11]
References
^
a
b Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin , 849 (849): 11–14,
Bibcode :
1927BHarO.849...11S .
^
a
b Goldsbury, Ryan; et al. (December 2010). "The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters". The Astronomical Journal . 140 (6): 1830–1837.
arXiv :
1008.2755 .
Bibcode :
2010AJ....140.1830G .
doi :
10.1088/0004-6256/140/6/1830 .
S2CID
119183070 .
^
a
b
c Hessels, J. W. T.; et al. (November 2007), "A 1.4 GHz Arecibo Survey for Pulsars in Globular Clusters", The Astrophysical Journal , 670 (1): 363–378,
arXiv :
0707.1602 ,
Bibcode :
2007ApJ...670..363H ,
doi :
10.1086/521780 ,
S2CID
16914232 .
^
a
b
NGC 6934 ,
SEDS , retrieved 2010-10-09
^
a
b Forbes, Duncan A.; et al. (October 2008). "Uniting old stellar systems: from globular clusters to giant ellipticals". Monthly Notices of the Royal Astronomical Society . 389 (4): 1924–1936.
arXiv :
0806.1090 .
Bibcode :
2008MNRAS.389.1924F .
doi :
10.1111/j.1365-2966.2008.13739.x .
S2CID
14108457 .
^
a
b Dinescu, Dana I.; et al. (October 2001). "Orbits of Globular Clusters in the Outer Galaxy: NGC 7006". The Astronomical Journal . 122 (4): 1916–1927.
arXiv :
astro-ph/0106259 .
Bibcode :
2001AJ....122.1916D .
doi :
10.1086/323094 .
S2CID
1232455 .
^
a
b
c Boyles, J.; et al. (November 2011), "Young Radio Pulsars in Galactic Globular Clusters", The Astrophysical Journal , 742 (1): 51,
arXiv :
1108.4402 ,
Bibcode :
2011ApJ...742...51B ,
doi :
10.1088/0004-637X/742/1/51 ,
S2CID
118649860 .
^
"NGC 6934" .
SIMBAD .
Centre de données astronomiques de Strasbourg . Retrieved 2020-10-08 .
^
a
b Marino, A. F.; et al. (June 2018).
"Metallicity Variations in the Type II Globular Cluster NGC 6934" . The Astrophysical Journal . 859 (2): 20.
arXiv :
1804.04158 .
Bibcode :
2018ApJ...859...81M .
doi :
10.3847/1538-4357/aabdea .
S2CID
119461759 . 81.
^
a
b Kaluzny, J.; et al. (March 2001). "Image-Subtraction Photometry of Variable Stars in the Field of the Globular Cluster NGC 6934". The Astronomical Journal . 121 (3): 1533–1550.
arXiv :
astro-ph/0010303 .
Bibcode :
2001AJ....121.1533K .
doi :
10.1086/319411 .
S2CID
14431121 .
^ Wilhelm, R.; et al. (December 2002). "Does NGC 6934 Have a Tidal Tail?". Bulletin of the American Astronomical Society . 34 : 1101.
Bibcode :
2002AAS...201.0702W .
External links