M6 - NGC 6405
DSS image of M6
Overlaid DSS image of M6, 30' x 30' with north at top and west to the right

Aladin viewer for the region around M6
Butterfly Cluster
Lac III.12, Bode 39, h 3699, GC 4318, Mel 178, Cr 341, C 1736-321, OCl 1030.0

Type  Open Cluster
Magnitude  4.2
Size  15'
Right Ascension  17h 40'  (2000)
Declination  32° 15' S
Constellation  Scorpius
Description  Cl, L, iR, lC, st7, 10...
Classification  III 2 p
Observing Notes

Andrew Cooper
Jun 27, 2020    Waikoloa Quarry, HI (map)
8x42mm Nikon Prostaff 3S Binoculars @ 8x

Bright and easy to find above Shaula, large, fully resolved, a rich cluster of 6-8th magnitude stars 1/2° across, a lovely binocular object in a very rich region

Andrew Cooper
Jun 27, 2020    Waikoloa Quarry, HI (map)
28cm f/10 SCT, NexStar 11" GyPSy @ 80x

Big! bright! fully resolved, a coarse collection of 7-9th magnitude stars over a 20' area, a handful of brighter stars punctuate the cluster including the bright 5.6 magnitude orange star BM Sco conspicuous in the eastern reach, the 8.6 magnitude V862 Sco is found in the northwestern side, the bright white V994 Sco at the southwestern edge

Andrew Cooper
Jun 29, 2019    Kaʻohe, Mauna Kea, HI (map)
8x42mm Nikon Prostaff 3S Binoculars @ 8x

Small and very bright, a tight and well defined cluster seen against a darker region of the galactic plane, fully resolved in the binos

Andrew Cooper
Jun 29, 2019    Kaʻohe, Mauna Kea, HI (map)
20cm f/6 Newtonian, Cave Astrola @ 56x

A beautiful bright cluster, a striking group that fills the field of view, bright, large, fully resolved, several dozen stars arranged in notable loops out from the center

Andrew Cooper
May 13, 2018    Kaʻohe, Mauna Kea, HI (map)
20cm f/6 Newtonian, Cave Astrola @ 56x

A distinct grouping of a few dozen bright stars, bright, coarse, fully resolved, quite a nice sight in the eyepiece

Andrew Cooper
Mar 14, 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
Jun 28, 1998    Santa Rita Mts., AZ (map)
20cm f/10 SCT

Bright. bold cluster of 50+ stars, visible naked eye

Charles Messier
May 23, 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."
― Connaissance des Temps, 1781

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.
Other Data Sources for M6
Associated objects for M6
Nearby objects for M6
5 objects found within 60'
BM Sco NGC 6404 Trumpler28
V862 Sco V994 Sco

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

A complete list of credits and sources can be found on the about page