Messier 54

Messier 54
M54 by Hubble Space Telescope; 3.4′ view
Observation data (J2000 epoch)
ClassIII[1]
ConstellationSagittarius
Right ascension18h 55m 03.33s[2]
Declination−30° 28′ 47.5″[2]
Distance87.4 kly (26.8 kpc)[3]
Apparent magnitude (V)7.6[4]
Apparent dimensions (V)12.0′
Physical characteristics
Radius153 ly[5]
Estimated age13 Gyr[6]
Notable featuresProbably extragalactic
Other designationsM54,[7] NGC 6715,[7] GCl 104,[7] C 1851-305[7]
See also: Globular cluster, List of globular clusters

Messier 54 (also known as M54 or NGC 6715) is a globular cluster in the constellation Sagittarius.[a] It was discovered by Charles Messier in 1778 and then included in his catalog of comet-like objects.

It is easily found in the sky, being close to the star ζ Sagittarii. It is, however, not resolvable into individual stars even with larger amateur telescopes.

In July 2009, a team of astronomers reported that they had found evidence of an intermediate-mass black hole in the core of M54.[8]

  1. ^ Cite error: The named reference hcob849_11 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference aj140_6_1830 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference ramsay_wu_2005 was invoked but never defined (see the help page).
  4. ^ "Messier 54". SEDS Messier Catalog. Retrieved 29 April 2022.
  5. ^ From trigonometry: radius = distance × sin( diameter_angle / 2 ) = 153 ly.
  6. ^ Geisler, Doug; Wallerstein, George; Smith, Verne V.; Casetti-Dinescu, Dana I. (2007). "Chemical Abundances and Kinematics in Globular Clusters and Local Group Dwarf Galaxies and Their Implications for Formation Theories of the Galactic Halo". Publications of the Astronomical Society of the Pacific. 119 (859): 939–961. arXiv:0708.0570. Bibcode:2007PASP..119..939G. doi:10.1086/521990. S2CID 119599242.
  7. ^ a b c d Cite error: The named reference simbad was invoked but never defined (see the help page).
  8. ^ Ibata, R.; Bellazzini, M.; Chapman, S. C.; Dalessandro, E.; et al. (2009). "Density and Kinematic Cusps in M54 at the Heart of the Sagittarius Dwarf Galaxy: Evidence for a 104 M☉ Black Hole?". Astrophysical Journal Letters. 699 (2): L169–L173. arXiv:0906.4894. Bibcode:2009ApJ...699L.169I. doi:10.1088/0004-637X/699/2/L169. S2CID 15976588.


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