Continued testing on a night of exceptionally stable air
We had exceptionally stable air at the New Mexico observatory tonight, and the image of the Bubble Nebula is the beneficiary.
The equipment we’re using to take photographs at this early stage of development is pretty ordinary, so we had to work extra hard to get a good result. This is a carefully orchestrated combination of 65 one-minute exposures of the nebula with a Canon 6D camera attached to the telescope.
The telescope itself is one meter in diameter, and has really amazingly sharp optics.
Technical info: The seeing was so stable that the FWHM of the central stars is less than one arc second (seeing ranged from 0.7” to 0.9” for most of the time spent collecting the individual images).
The images were combined statistically (removing noise and increasing signal by a process called “stacking”) in Pix Insight, a sophisticated bit of software that uses advanced algorithms for such efforts.
So despite having a very old full-frame digital camera, despite terribly short exposures, and with the benefit of amazing seeing conditions and first-rate software, we got a wonderful image.