NGC 2360

From Infogalactic: the planetary knowledge core
Jump to: navigation, search
NGC 2360
300px
NGC 2360 (taken from Stellarium)
Credit: Roberto Mura
Observation data (J2000 epoch)
Constellation Canis Major
Right ascension 07h 17m 43s[1]
Declination −15° 38′ 29″[1]
Apparent magnitude (V) 7.2[2]
Apparent dimensions (V) 13′[2]
Physical characteristics
Other designations Cl Melotte 64,[3] Caldwell 58, Caroline's Cluster[3]
See also: Open cluster, List of open clusters
File:NGC 2360 map.png
Map showing the location of NGC 2360

NGC 2360, also known as Caroline's Cluster,[3] is an open cluster in the constellation Canis Major. It was discovered on 26 February 1783,[4] by Caroline Herschel who wrote, "A beautiful cluster of pretty compressed stars near 1/2 degree in diameter."[5] Her notes were overlooked until her brother William included the cluster in his 1786 catalogue of 1000 clusters and nebulae and acknowledged her as the discoverer.[4] The cluster lies 3.5 degrees east of Gamma Canis Majoris and less than one degree northwest of the eclipsing binary star R Canis Majoris; it has a combined apparent magnitude of 7.2.[5] It is 13 arc minutes in diameter.[2] By the western edge of the cluster is the unrelated star, 5.5-magnitude HD 56405.[6]

American astronomer Olin J. Eggen surveyed the cluster in 1968, concluding that the brightest star in the field, magnitude-8.96 HD 56847, is likely to lie in the field and not a true member of the cluster. He also identified one or possibly two blue stragglers.[7] These are unexpectedly hot and luminous stars that appear younger than surrounding stars, and have likely developed by sucking matter off companion stars.[8] Four are now recognised to be in the cluster.[9] By analysing the masses of the smallest stars that have evolved into red giants—namely, stars of 1.8 or 1.9 solar masses—Swiss astronomers Jean-Claude Mermilliod and Michel Mayor were able to date the age of the cluster at 2.2 billion years.[10] The cluster has a diameter of around 15 light-years and is located 3700 light-years from Earth.[5]

Notes

  1. 1.0 1.1 Lua error in package.lua at line 80: module 'strict' not found.
  2. 2.0 2.1 2.2 Lua error in package.lua at line 80: module 'strict' not found.
  3. 3.0 3.1 3.2 Lua error in package.lua at line 80: module 'strict' not found.
  4. 4.0 4.1 Lua error in package.lua at line 80: module 'strict' not found.
  5. 5.0 5.1 5.2 Lua error in package.lua at line 80: module 'strict' not found.
  6. Lua error in package.lua at line 80: module 'strict' not found.
  7. Lua error in package.lua at line 80: module 'strict' not found.
  8. Lua error in package.lua at line 80: module 'strict' not found.
  9. Lua error in package.lua at line 80: module 'strict' not found.
  10. Lua error in package.lua at line 80: module 'strict' not found.

External links

Coordinates: Sky map 07h 17m 42s, −15° 38′ 00″