M51 (NGC 5194 and NGC 5195, Whirlpool Galaxy) in H-alpha and continuum light
M51 (also known as Whirlpool Galaxy) are two interacting galaxies in constellation Canes Venatici. The larger one (M51A or NGC 5194) is a grand-design spiral galaxy.
Its smaller companion (M51B or NGC 5195) is a dwarf galaxy that is highly distorted from the interaction with M51A.
0.31° × 0.36°
400mm Newton at f=1520mm
North is up (approximately)
0.8 arcsec/pixel (at full resolution)
Total exposure times:
All image processing steps are deterministic, i.e. there was no manual retouching or any other kind of non-reproducible adjustment. The software which was used can be downloaded here.
Image processing steps where:
Bias correction, photon counting
Dark current subtraction, flatfield correction, noise estimation
Alignment and brightness calibration using stars from reference image
Stacking with masking unlikely values and background correction