Andrew Cooper
Jun 23, 2020    Waikoloa, HI (map)
20cm f/6 Newtonian, Cave Astrola @ 61x
Seeing: 6 Transparency: 6 Moon: 0%

Small, bright, not resolved, dense core, more modest than the other Messier Oph globular clusters

Andrew Cooper
Jun 10, 2010    Hale Pohaku, HI (map)
46cm f/4.5 Newtonian, Deep Violet @ 175x
Seeing: 8 Transparency: 7.5 Moon: 0%

Nice, bright, good sized at 10', fully resolved with a smooth appearance lent by a population of stars evenly matched in magnitude, not very concentrated at the core

Andrew Cooper
Apr 18, 2010    Hale Pohaku, HI (map)
46cm f/4.5 Newtonian, Deep Violet @ 175x
Seeing: 6 Transparency: 7 Moon: 0%

Big, bright, 5' in diameter, fully resolved, a very nice globular, core is not very concentrated with a gradual increase from the margin

Andrew Cooper
Jun 6, 1998    TIMPA, Avra Valley, AZ (map)
20cm f/10 SCT

Smaller and dimmer than M10 & M12 but not bad, not resolved with the 20cm (8")

Rev. T.W. Webb
May 19, 1885    Hardwick, Herefordshire, England (map)

Large; glimpses of resolution, effected by H. with 20-ft. reflector. (h., 15 or 16 mg., 'the finest star dust.')

― Celestial Objects for Common Telescopes, T. W. Webb, 1917

Charles Messier
Jun 1, 1764    

Nebula without star, discovered in the garb which dresses the right arm of Ophiuchus, & situated on the parallel of Zeta of Serpens: this nebula is not large, its light is faint, one can see it nevertheless with an ordinary telescope of three feet and a half; it is round, near it is a small star of the ninth magnitude; its position has been determined by comparing it with Gamma of Ophiuchus, & M. Messier has reported its position on the Chart of the Comet of 1769. Memoirs de l'Academy, year 1775, plate IX. Seen again on March 22, 1781

― Connaissance des Temps, 1781

William Herschel
45cm f/12.8 Herschelian speculum

Extremely bright, round, easily resolvable; with 300 I can see the stars. The heavens are pretty rich in stars of a certain size, but they are larger than those in the cluster, and easily to be distinguished from them. The cluster is considerably behind the scattered stars, as some of them are projected upon it.

Drawings, descriptions, and CCD photos are copyright Andrew Cooper unless otherwise noted, no usage without permission.

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