This image shows Messier 101, also known as the Pinwheel Galaxy, a large face-on spiral located in the constellation Ursa Major.

Its wide, open spiral arms are filled with countless star-forming regions, visible here as small pink knots of hydrogen emission scattered across the galaxy. These are vast clouds where new stars are being born, giving M101 a patchy and dynamic appearance compared to more uniform spiral galaxies.

The structure of M101 looks almost asymmetric, with arms that seem loosely wound and slightly distorted. This is likely the result of gravitational interactions with nearby companion galaxies, shaping its form over time.

Surrounding the galaxy is a rich background of distant stars and faint galaxies, adding depth to the scene. Even though M101 appears soft and delicate, it is an enormous system, spanning well over 100,000 light-years.

Data:
Location: Upper Austria

Capture date: April 2026

Lights (Gain 139, -15°, Binning 1x1)
Red: 91x180s
Green: 91x180s
Blue: 91x180s
Luminance: 156×180s
Halpha: 105×360s
Darks: 5x20
Bias: 50
Flats: 5x25
Darkflats: 5x25

Equipment:
Telescope:
Skywatcher 200PDS

Camera:
ZWO ASI1600MM - Cool

Filter:
Baader 31mm Ha 6.5nm
Baader 31mm UV/IR Cut
Baader 31mm Red
Baader 31mm Green
Baader 31mm Blue

Filter wheel:
ZWO EFW 8x 31mm

Corrector:
GPU Coma Corrector

Mount:
Skywatcher EQ6R Pro

Guiding:
ZWO OAG with ZWO ASi290mm and PHD2

Software:
Astro Pixel Processor, Pixinsight, Adobe Photoshop