Der Rosettennebel (C49/NGC2237)

2/22
ASI2600MC Pro, ~12x 180s RGB (0.6h) + ~21x 900s Ha&O (5.4h)

The hydrogen and oxygen contained in this gigantic molecular cloud with a diameter of roughly 130 lightyears in constellation Monoceros are excited from a couple of young stars and so generate the iconic shape of the Rosette Nebula.