M101 (Pinwheel Galaxy) in H-alpha and continuum light
M101 (also known as Pinwheel Galaxy) is a spiral galaxy in constellation Ursa Major which lies in a distance of about 21 million light-years.
Its a large galaxy with a diameter of about 170,000 light-years and it is the largest member of the M101 group which belongs (together with many others including the Local Group) to the Virgo Supercluster.
0.5° × 0.44° (full view)
400mm Newton at f=1520mm
North is up (approximately)
Total exposure times:
Yellow (540nm to 650nm):
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, dark current subtraction, flatfield correction
Alignment and brightness calibration using stars from reference image
Stacking with masking unlikely values and background correction
Denoising and deconvolution
Dynamic range compression using non-linear high-pass filter