Palomar 5

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Palomar 5
Observation data (J2000 epoch)
Class XII
Constellation Serpens
Right ascension 15h 16m 05.3s[1]
Declination –00° 06′ 41″[1]
Distance 76 kly (23 kpc)[2]
Apparent magnitude (V) +11.75
Apparent dimensions (V) 6′.9
Physical characteristics
Mass 3.00×104[3] M
Radius 76 ly[4]
Estimated age 11.5±1.0 Gyr[5]
Notable features Erroneously thought to be a dwarf galaxy
Other designations UGC 9792, GCl 32[1]
See also: Globular cluster, List of globular clusters

Palomar 5 is a globular cluster discovered by Walter Baade in 1950. It was independently found again by Albert George Wilson in 1955. After the initial name of Serpens, it was subsequently catalogued as Palomar 5.

There is a process of disruption acting on this cluster because of the gravitation of the Milky Way - in fact there are many stars leaving this cluster in the form of a stellar stream. The stream has a mass of 5000 solar masses and is 30,000 light years long.[6] The cluster is currently 60.6 kly (18.6 kpc) from the Galactic Center. It shows a noticeable amount of flattening, with an aspect ratio of 0.62 ± 0.23 between its semimajor axis and semiminor axis.[7]

References[edit]

  1. ^ a b c "SIMBAD Astronomical Database". Results for Palomar 5. Retrieved 2006-11-17. 
  2. ^ 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. 
  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. 
  4. ^ distance × sin( diameter_angle / 2 ) = 76 ly. radius
  5. ^ Martell, S. L.; Smith, G. H.; Grillmair, C. J. (2002). "A New Age Measurement for Palomar 5". American Astronomical Society, 201st AAS Meeting, #07.11; Bulletin of the American Astronomical Society 34: 1103. Bibcode:2002AAS...201.0711M. 
  6. ^ Ibata, Rodrigo; Gibson, Brad (April 2007). "The Ghosts of Galaxies Past". Scientific American 296 (4): 40–45. doi:10.1038/scientificamerican0407-40. ISSN 0036-8733. PMID 17479629. 
  7. ^ Chen, C. W.; Chen, W. P. (October 2010), "Morphological Distortion of Galactic Globular Clusters", The Astrophysical Journal 721 (2): 1790–1819, Bibcode:2010ApJ...721.1790C, doi:10.1088/0004-637X/721/2/1790 

External links[edit]

Coordinates: Sky map 15h 16m 05.3s, −00° 06′ 41″