Pinwheel Galaxy

Designation: M101
Hemisphere: Northern
Constellation: Ursa Major
Distance: 25 million light years
Object type: Spiral galaxy


The Pinwheel Galaxy is a face-on spiral galaxy located 25 million light-years away from Earth, in the constellation Ursa Major. With a diameter of approx. 170,000 light-years across, the galaxy is nearly double the size of our Milky Way and it’s believed to contain at least one trillion stars.

The Pinwheel Galaxy’s arms are home to many H II regions that are ionized by several of extremely bright and hot young stars; here new stars are forming from the molecules of hydrogen clouds.

In this image I also captured a bunch of smaller galaxies, including the dwarf galaxy NGC 5474 and the lenticular galaxy NGC 5422, which is estimated to be about 100 million light years away. All designations in the image below.


Mount: Sky-watcher HEQ5-Pro
Main Telescope: William Optics ZS73EDii
Main camera: ZWO ASI294MC-Pro
Main camera filters: Optolong L-Pro + Optolong UV/IR Cut + IDAS NBZ
Guidescope: AstroEssential 50/200
Guide camera: ZWO ASI174MM
Guide camera filter: Astronomik UV/IR cut

Acquisition details

Total integration time: 17 hours 10 minutes
Acquisition: ZWO AsiAir Plus
Processing: PixInsight
Locations: France and Luxembourg

Where the universe begins…