Delle Caustiche in Sagittarius

Full view for maximum effect.

Delle Caustiche, The Small Sagittarius Star Cloud (M24) in Sagittarius

The Small Sagittarius Star Cloud is a window into the Milky Way, which forms a rich region of the Sagitarrius spiral arm.

Very few objects can match its visual grace when seen through binoculars or low-powered telescopes. M24 occupies approximately 1x2 degrees of the sky.

This dense region of the sky contains a wonderful example of a Bernard Dark Nebula in the guise of B92 (blackened region towards the centre-right of the cloud).

The faint open cluster in the bottom left, above the pink nebulosity is NGC 6568. The circular pink nebula towards the left of the star cloud is IC1283-4.

On the right-hand side of the cloud we have the Omega/Horseshoe/Swan Nebula (M17). Between M17 and the M24 is a small open cluster; this is the Black Swan (M18) cluster.

The winning combination of bright stars, dark areas and faint nebulosity adds to the visual impact and complexity of this remarkable stellar city.

This composite consists of one set of images; one set of 16 images taken at ISO-400.
Each individual image was a 240 second exposure.
IRIS was used to calibrate each image (dark subtraction [median combined master dark] and flat field division [median combined master flat {lights and darks}]), to register, align, and finally stack.
Photoshop CS2 was used to adjust levels, curves, frame and resize the final composite.

Target: Delle Caustiche, The Small Sagittarius Star Cloud (M24) in Sagittarius
Date: Saturday, July 14th, 2007
Time: First image: 01:28 AM
Time: Last image: 02:34 AM
Location: Lake Bathurst, NSW, Australia
Camera: Canon EOS-350D (modified: Baader UV/IR filter)
Lens: Nikkor ED 180mm F/2.8 (stopped down to F/4.0)
Focal length: 180mm
Mount: Takahashi EM-200
Exposure: 16 x 240 seconds (1 hour and 4 minutes) @ ISO-400 (RAW)
Software: IRIS: Calibration, registration, stacking; Adobe Photoshop CS2: post-processing and framing