Messier 15

Messier 15
Deep Broadband (RGB) image of M15 from the Mount Lemmon SkyCenter
Deep Broadband (RGB) image of M15
Observation data (J2000 epoch)
ClassIV[1]
ConstellationPegasus
Right ascension21h 29m 58.33s[2]
Declination+12° 10′ 01.2″[2]
Distance35.69 ± 0.43 kly (10.944 ± 0.131 kpc)[3]
Apparent magnitude (V)6.2[4]
Apparent dimensions (V)18′.0
Physical characteristics
Mass5.6×105[5] M☉
Radius~88 ly[6]
VHB15.83
Metallicity = –2.37[7] dex
Estimated age12.0 Gyr[8]
Notable featuressteep central cusp
Other designationsNGC 7078, GCl 120[9]
See also: Globular cluster, List of globular clusters

Messier 15 or M15 (also designated NGC 7078 and sometimes known as the Great Pegasus Cluster) is a globular cluster in the constellation Pegasus. It was discovered by Jean-Dominique Maraldi in 1746 and included in Charles Messier's catalogue of comet-like objects in 1764.[citation needed] At an estimated 12.5±1.3 billion years old, it is one of the oldest known globular clusters.[10]

  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 Bhardwaj was invoked but never defined (see the help page).
  4. ^ "Messier 15". SEDS Messier Catalog. Retrieved 21 July 2024.
  5. ^ Cite error: The named reference mnras406_3_2000 was invoked but never defined (see the help page).
  6. ^ distance × sin( diameter_angle / 2 ) = 88 ly radius
  7. ^ Cite error: The named reference apj742_1_51 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference mnras385_4_1998 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference simbad was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Malley was invoked but never defined (see the help page).