How to photograph the Whirlpool Galaxy (M51)
A face-on spiral tugging on its smaller companion, NGC 5195.
Photo byNASA and European Space Agency(Public domain)
When to shoot it from your location
About the Whirlpool Galaxy
The Whirlpool is small, so it needs 800mm or more to show its spiral arms in detail. It sits high in spring skies in the Northern Hemisphere and is a popular galaxy target for longer telescopes.
Gear and framing
The Whirlpool Galaxy spans about 11′ of sky. It frames best with:
- Long focal length (800mm and up)
You can see how other people have built their rigs on RigDesigner, including my Sony a6700 and 60mm refractor rig.
Filters
This is a broadband target, which means its light is mostly starlight across the whole spectrum. Shoot it with no filter or a UV/IR cut filter. A broadband light pollution filter can help a little in the suburbs. Dual-band and narrowband filters block most of its light, so leave them off. Plan it for a moonless night at a dark site.
Tips
- Good guiding matters at long focal lengths. Check your guiding RMS before committing a night to it.
- With a small refractor, crop in or use it as part of a wider field with M63 nearby.
Processing
Stack your light frames with darks and flats, then remove the background gradient before stretching. AstroBake does all of this for you. Point it at your folders of raw frames, then adjust the result with live sliders.