NGC 6366

Also Known as: GLC 65

Object Type: Globular Cluster

Constellation: Ophiuchus

Distance from Earth: 11,700 light years

Apparent Magnitude: 9.5

Coordinates: RA 17H 27M 44.3S DEC 04deg -05min 36sec

Actual Size: 44 light years

Apparent Dimensions: 13 arc-minutes

Discovered by: NGC 6366 globular cluster was discovered on 12 April 1860 by the German astronomer August Winnecke using his private 3 inch Merz refractor while he was working at Pulkowo Observatory south of St. Petersburg.

Description: NGC 6366 is similar in composition to M71 or NGC 6342.
It is designated as XI in the galaxy morphological classification scheme
NGC 6366 is usually overlooked in favour of the splashier globular clusters of Ophiuchus, like M10, M12 and M14.
It is so sparse that it barely looks like a globular cluster at all.
It is small and dim, covering less than a half-Moon’s width in the sky.
Although it might not compete with its siblings for brilliance, there are some facts that make it interesting: it is a “metal rich” cluster, meaning its stars have relatively large amounts of elements heavier than hydrogen and helium. It contains relatively few low mass stars; one theory is that the lower mass stars have been stripped away by the main portion of the Milky Way galaxy through “tidal stripping.”
NGC 6366 is a metal-rich Galactic globular cluster and the fifth closest to the Sun.
Its kinematics suggests a link to the galactic halo, but its metallicity indicates otherwise.
A presence of second generation stars is not evident.
Due to the high interstellar absorption in this direction, the cluster appears clearly reddened and shows a nice color contrast with the blue, bright foreground star.
Compared to other globulars, the cluster is rather rich in elements heavier than Helium, which astronomers sometimes inaccurately like to call metals.
NGC 6366 is approaching us at 122 km/s.

Click Below Image(s) for Full Size:

Directly east of the bright star 47 Ophiuchi you can find the very loosely concentrated globular cluster NGC 6366.
Due to the high interstellar absorption in this direction, the cluster appears clearly reddened and shows a nice color contrast with the blue, bright foreground star.
NGC 6366 is quite faint and weakly concentrated even in intermediate-sized amateur telescopes.
As its brightest stars are only of magnitude 13.6, larger telescopes are required to view them; the horizontal branch giants are of magnitude 15.7.
The overall visual magnitude of 9.2, at its distance of 11,700 light years and taking into account the interstellar absorption in its direction, gives an absolute visual brightness of -5.77 magnitudes, or a luminosity of only about 20,000 times that of our sun.

NGC 6366 is situated close to the celestial equator and, as such, it is at least partly visible from both hemispheres in certain times of the year.

Platesolve

NGC 6366 Globular Cluster

Imaging Details
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