Going Deep on the Whirlpool
This year, I revisited M51, the “Whirlpool Galaxy.” Having seem some images of this with hundreds of hours of exposure time that pulled out features I never knew were there, I wanted to give it a go myself. This image incorporates over 120 hours of exposure time – but honestly, it doesn’t look much different from an image with 20 hours.
My mistake was using sub-exposures that were too short. Even with modern CMOS cameras, the read noise can drown out super-faint signals. My 10-minute subs just weren’t enough to pick up the detail I was after; 30 minutes would be more appropriate. Live and learn!
Still, it’s a cool image. I’ve never gotten that much depth on the tidal tails of this thing, nor as much detail on the Hydrogen clouds within it.
