NGC5194 (M51) - The Whirlpool Galaxy and its companion NGC5195 - Ha enhanced Natural colors image enhanced with Ha-narrow band contribution of NGC5194 (M51) and its interacting companion NGC5195.
In this image, the Ha contribution has been enhanced on purpose because it seems to be a diffuse but faint presence of Hydrogen also outside of the main HII regions. Some very faint HII regions are visible through the halo just below and along the bottom arm of the spiral galaxy. Compare this image with the more classical one in the previous frame:
http://www.astrobrallo.com/gallery/index.php/DOME-2/color/M51-Oss-Trivolzio-Nor-01-05-2014


L=420 Ha=330 R=120 G=120 B=120

Telescope: Dall-Kirkham Astrograph 12" F/7.8
Mount: Custom Fork Mount
CCD: SBIG ST10 XME
Filters: Astronomics LRGB
SER Observatory - Trivolzio

Author: M. Angelini - F.Antonucci