Messier 25

Messier 25
Open cluster Messier 25 in Sagittarius
Observation data (J2000.0 epoch)
Right ascension18h 31m 47.0s[1]
Declination−19° 07′ 00″[1]
Distance2,000 ly (620 pc)[2]
Apparent magnitude (V)4.6[3]
Apparent dimensions (V)36′[2]
Physical characteristics
Mass1,937 M☉[4] M☉
Radius6.5 light-years[4]
Estimated age67.6 million years[2]
Other designationsMessier 25,[5] IC 4725, Cr 382, C 1828–192, Mel 204
Associations
See also: Open cluster, List of open clusters

Messier 25, also known as IC 4725, is an open cluster of stars in the southern constellation of Sagittarius. The first recorded observation of this cluster was made by Philippe Loys de Chéseaux in 1745 and it was included in Charles Messier's list of nebulous objects in 1764.[6] The cluster is located near some obscuring features, with a dark lane passing near the center.[7]

M25 is at a distance of about 2,000 light-years away from Earth and is 67.6 million years old.[2] The spatial dimension of this cluster is about 13 light-years across. It has an estimated mass of 1,937 M☉, of which about 24% is interstellar matter.[4] A Delta Cephei type variable star designated U Sagittarii is a member of this cluster,[8] as are two red giants, one of which is a binary system.[9]

New research indicates M25 may constitute a ternary star cluster together with NGC 6716 and Collinder 394.[10]

  1. ^ a b Cite error: The named reference Wu2009 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference kharchenko2005 was invoked but never defined (see the help page).
  3. ^ "Messier 25". SEDS Messier Catalog. Retrieved 21 July 2024.
  4. ^ a b c Cite error: The named reference Tadross2002 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Thompson2007 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Landolt1964 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Wampler1961 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Mermilliod1987 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Majaess2024 was invoked but never defined (see the help page).