| Type | Open Cluster |
|---|---|
| Magnitude | 4.2 |
| Size | 15' |
| RA (2000) | 17h 40' 20.6" |
| Dec (2000) | 32° 15' 15" S |
| Constellation | Scorpius |
| Description | Cl, L, iR, lC, st7, 10... |
Andrew Cooper
14 Mar 2010 Hale Pohaku, HI (map)
15cm f/5 Newtonian, Primero @ 55x
Very bright! Large! bright and loose cluster filling the low power field, obvious to the unaided eye above the tail of Sco
Andrew Cooper
28 Jun 1998 Santa Rita Mts., AZ (map)
20cm f/10 SCT
Bright. bold cluster of 50+ stars, visible naked eye
Charles Messier
23 May 1764
A cluster of small stars between the bow of Sagittarius & the tail of Scorpius. At simple view, this cluster seems to form a nebula without stars; but even with the smallest instrument one employs for investigating one sees a cluster of small stars."
William Herschel
45cm f/12.8 Herschelian speculum
20 feet, lowest power. I counted about 50 stars; it contains the greatest variety of magnitudes of any nebula I recollect. The compound eye-piece shows more of them variously and intermixed.
Drawings, descriptions and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission. Use for non-profit and educational reasons is generally given on request.
Positional and some physical information is from the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.
Additional object data from the SIMBAD database, operated at CDS, Strasbourg, France.
The Digitized Sky Survey was produced at the Space Telescope Science Institute under U.S. Government grant NAG W-2166. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope.
Dark nebulae data from E.E. Barnard, A Photographic Atlas of Selected Regions of the Milky Way. Ed. Edwin B. Frost and Mary R. Calvert. Carnegie Institution of Washington, 1927
Object descriptions of Rev. Webb from Celestial Objects for Common Telescopes sixth edition, Rev. T.W. Webb, 1917, edited by Rev T.E.Espin.