SOUTHERN CROWN

Located in the constellation Corona Australis (Southern Crown), the spectacular object NGC 6729 (AKA Caldwell 68) is a combined reflection and emission nebula, set within the Australis Molecular Cloud.  Being just south of Sagittarius, it is inaccessible from my observatory in Somerset, so this excellent data was consequently acquired from the dark skies of Chile in the Southern Hemisphere, using a superb Planewave CDK200 f/6.8 508cm aperture telescope at the El Sauce Observatory. 

     

The star illuminating NGC 6729 is a T Tauri star – a type of young star whose brightness fluctuates over time.  The fan-shaped nebula opens-up between the variable stars R Corona Australis (R CrA) and T CrA to the south-east (see skymap below ref. Robert Mura).  R CrA is a pre-main-sequence star within the Corona Australis molecular complex, which is one of the closest star-forming regions to the Milky Way galaxy.  Intriguingly, this wonderful, hazy looking nebula exhibits both variable brightness and morphology over time.

Avian Astronomy: Seagull Nebula

Located 3,650 light-years from Earth, in the area between the Monoceros and Canis Major constellations, is the emission and reflection nebulae complex of the so-called Seagull Nebula.  It’s been 8-years since I last briefly dabbled with imaging this exciting object and for good reason.  From my position, this bird flies at a maximum 28o above the southern horizon (-11 DEC) and, furthermore, spends much of its time behind houses, trees, and tall hedges, thus providing just two short windows for imaging; combined with this winter’s terrible weather it made for a tough but ultimately rewarding target. 

   

The Seagull’s approximate flight path seen from Fairvale Observatory makes imaging difficult

Whilst popularly known as the Seagull Nebula, the bird consists of a number of fabulous objects spanning some 200 light-years in their entirety: the Seagull’s head (SH2-292) and wings (IC 2177), the large open star cluster along the leading edge of the left wing (NGC 2335) and a smaller cluster on the edge of the right wing (NGC 2327), the nebula at the tip of the right wing (Sh2-297), as well as many other named features (Sharpless and LBN) that are highlighted in the following plate solved image (below).

Despite the difficulties posed by the low transit of the bird in the night sky, each of the Ha, OIII and SII wavelengths are strong, making for good data acquisition and a very pleasing final SHO image.