Caldwell 68

The juxtaposition of NGC 6729 with its gorgeous reflection nebulae and the sparkling globular cluster NGC 6723, set amongst an extensive molecular cloud, makes for a nice composition.

"NGC 6729 (also known as Caldwell 68) is a reflection/emission nebula of the Corona Australis Molecular Cloud in the constellation Corona Australis. This fan-shaped nebula opens from the star R Coronae Australis toward the star T CrA to the south-east. R CrA is a pre-main-sequence star in the Corona Australis molecular complex, one of the closer star-forming regions of the galaxy at a distance of 130 pc. NGC 6729 is a variable nebula which shows irregular variations in brightness and in shape."

"NGC 6723, also known as the Chandelier Cluster, is a globular cluster in the constellation Sagittarius. Its magnitude is given as between 6 and 6.8, and its diameter is between 7 and 11 arcminutes. It is a class VII cluster with stars of magnitude 14 and dimmer. It is near the border of Sagittarius and Corona Australis. Unlike common globular clusters, NGC 6723 has an enhanced metallicity and a large fraction of younger stars."....Wikipedia abridged

This is an LRGB image. The fine structure of the tendrils of the nebulae reflecting the blue star light is well resolved here and is a benefit of the smaller FOV and small image scale.

A distant galaxy can be seen in the lower part of the image and is PGC 62667. It seems to be a spiral galaxy, with a central ring and regularly spaced bright nodules around the ring. The spiral also shows Vorontsov-Velyaminov rows (straight sections in the spiral arms).

Data Capture: 2024-06-10 to 2024-08-08

OTA: C11 Edge HD

Mount: PME II

Camera: SBIG 16803

Filters: Astronomik 50mm unmounted LRGB

Coordinates……………. RA 19h 00mins 44.3sec, -36 °52' 05.7"

Total Integration Time: 22.5 hours

Luminance: 31 x 60 secs

Red: 37 x 60 secs

Green: 34 x 60 secs

Blue: 33 x 60 secs

Bias: 35

Darks: 35

Flat Darks: 35 per exposure time

Flats: 20 per colour channel

Copyright: Niall MacNeill