Actually I wanted to photograph the Rosette Nebula last night. But the nebula is a bit too big for the D5200 crop camera. Therefore I postponed it for now to try it again eventually this week with the D800.

As an alternative, I have programmed the software for the Iris Nebula. I had already made this object last year in September. At that time – as an appendage for the night – but only 175 light shots and no darks or bias. This time I made up for that and created a new image from all 275 (plus 50 darks and 25 bias) images. The total exposure time is now 13500 sec = 225 min = 3:45 hours.

NGC 7023 – Iris nebula

The nebula itself comes a little bit better into focus.

The astrometry data are of course the same as in the last session.