NGC 2403 (also known as Caldwell 7) is an intermediate spiral galaxy at a distance of approximately 10 million light-years. Despite being quite bright and relatively large, it was overlooked by Charles Messier and thus found no entry into his famous catalog. In fact, it is still little-known today, maybe because of its isolated location in Camelopardalis, a very inconspicuous constellation. It looks very similar to M33, being about 50,000 light-years in diameter. In the center of the galaxy are several large, open star clusters with massive, very hot stars embedded in red HII regions.
Telescope: 16″ f3.75 Dream Scope
Camera: FLI ML16803
Mount: ASA DDM85
Exposure: 8 hours (51x300s L + 3x14x300s RGB)
Data: December 2019 – Processing: January 2023
Location: Southern Alps, France