Hi All,
A galaxy, numerous clusters, and copious amounts of HII nebulosity has been my latest challenge, so without further ado, I’m pleased to present - NGC 292,
The Small Magellanic Cloud. A word of warning, the higher resolution images are large is will take sometime to load.
Located in the constellation Tuscana, the Small Magellanic Cloud (SMC/NGC292) is an irregular galaxy that is a member of the local group of galaxies. The term “irregular galaxy” refers to the fact that no apparent shape can been seen. It does not feature spiral or elliptical characteristics found in typical galaxy structures. The SMC contains numerous objects which have been catalogued that range from clusters through to rich redish-pink HII nebulae and is approximately 230,000 light years away.
To the upper right, the grand globular cluster 47 Tucanae (47Tuc/NGC104) shines bright, second only to the magnificent globular cluster Omega Centauri. 47 Tuc is among the closest clusters to us located approximately 20,000 light years away. To the upper left, is the smaller cluster NGC362 at a distance of approximately 40,000 light years.
A few words on the image (skip if you're not interested in details);
The image is a LRGB two frame mosaic with a total exposure time of 11.5 hours (L:120min;R75min;G:75min;B:75min per frame). The FOV of the FSQED/STL11k combination is actually large enough to compose the SMC in a single frame, however I wasn’t happy with the aesthetics – FOV too compact. I opted for a basic mosaic approach so I could also include surrounding areas of interest.
The mosaic composition was planned in TheSky with a 10% image overlap ensuring good alignment (and room for error) – TheSky planned can be viewed in the attachment section below. I don’t have a robotic instrument rotator for the FSQED (yet) so I used the Tak CAA manually to rotate the STL11k for initial framing to match the plan (@ 74 degrees position angle).
TheSky mosaic plan was then converted into an ACP imaging plan for automated image acquisition. I had “user error” problems with the telescope pointing model which lead to a slight frame misalignment. Frustrated, I shot the entire frame again after rectifying the problem. Luminance subs were 15min which was ideal to bring out the faint nebulosity around the cloud, however totally burnt out the surrounding star clusters. I wasn’t overly concerned about this as the main feature is the SMC itself. I took some additional 5min chrominance subs and layered them to reduce core burn though it is still present.
The vast dynamic range of the frames required quite some layering work. I paid the ultimate price in acquisition as the two frames ideally should have been taken reasonably closely together, however this was not the case – they were taken over a month a part (at significantly different moon phases). This resulted in considerable frame differences with gradients and colour shifts present. I found these rather complex to deal with especially with my “rusty” mosaic processing skills. Thoroughly enjoyed the HII redish/pink knots of nebulosity scattered around the galaxy – rather special.
The uploaded web image is reduced resolution and quality – the original is ~4800x3750 (18mp). Despite the pointing errors and other problems noted, I enjoyed the challenge that this mosaic presented so this will certainly not be my last.
Thanks for looking and hope you enjoy it.
Seasons greetings all!
Cheers