NGC 6522

NGC 6522

32 inch telescope
Observation data (J2000 epoch)
Constellation Sagittarius
Right ascension 18h 3m 34.1s[1]
Declination −30° 2 2.3[1]
Distance 25.1 kly (7.7 kpc)[2]
Physical characteristics
Mass 3.00×105[2] M
Metallicity \begin{smallmatrix}\left[{Fe}/{H}\right]\end{smallmatrix} = –1.34[2] dex
Estimated age 12.0 Gyr[3]

NGC 6522 is a globular cluster in the constellation Sagittarius. It was discovered by William Herschel on June 24, 1784. It is centered in a region of the sky known as Baade's Window.[1]

NGC 6522 is possibly the oldest star cluster in the Milky Way,[4] with an age of more than 12 Gigayears.[5]

References

  1. 1 2 3 "SIMBAD Astronomical Database". Results for NGC 6522. Retrieved 2011-03-13.
  2. 1 2 3 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.
  3. Koleva, M.; et al. (April 2008), "Spectroscopic ages and metallicities of stellar populations: validation of full spectrum fitting", Monthly Notices of the Royal Astronomical Society 385 (4): 1998–2010, arXiv:0801.0871, Bibcode:2008MNRAS.385.1998K, doi:10.1111/j.1365-2966.2008.12908.x
  4. "VLT-FLAMES Analysis of 8 giants in the Bulge Metal-poor Globular Cluster NGC 6522: Oldest Cluster in the Galaxy?" by B. Barbuy et al., 2009
  5. "The universe's first stars were whirling dervishes", New Scientist by David Shiga, 30 April 2011, p. 20. "Imprints of fast-rotating massive stars in the Galactic Bulge" by Cristina Chiappini et al., Nature 472, pp. 454–457 (28 April 2011).

External links

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