M51 - The Whirlpool Galaxy. Located around 23 million light years from Earth, it can be found not far from the Big Dipper. A face-on spiral galaxy, it is about 25-33% the size of the Milky Way. M51 is unique in that it is an excellent example of a galactic merger, where two galaxies merge together. The second galaxy, an elliptical galaxy known as NGC 5195, can be seen below M51 as the bright yellow region.

At first glance, the smaller NGC 5195 galaxy appears to be tugging on the arm. However, the Hubble Space Telescope showed that NGC 5195 is actually passing behind the Whirlpool. The small galaxy has been gliding past the Whirlpool for hundreds of millions of years. As NGC 5195 drifts by, its gravitational force creates ripples within the Whirlpool’s pancake-shaped disk. Star-forming regions can be seen in the magenta areas, whereas many of the older stars reside near the yellowish core of M51.

I feel like given my setup’s focal length, this was about as much detail as I could resolve in M51, and this was cropped fairly heavily. I’m hoping to get a longer focal length scope (~1600mm instead of 800mm) at some point in the distant future to be able to better resolve better details in these more distant galaxies and nebulae. I shot M51 as my last target for the night and got an hour of good data in before sunrise.

Telescope: Orion 8" f/3.9 Astrograph

Mount: Skywatcher EQ6-R Pro

Imaging Camera: ZWO ASI 071 MC Pro

Coma Corrector: Skywatch Aplanatic CC

Guiding: Orion Starshoot Auto Guider

Polar Alignment: QHY Polemaster

Lights: 12 x 300s = 1 hour of total exposure

Gain: 90

Offset: 20

Darks: none

Flats: none

Bias: none

Taken from a Bortle 1 zone in Death Valley NP, CA

Stacked in DeepSkyStacker

Adjusted levels & curves in Photoshop until I got a reasonably contrasty image

Used Gradient Xterminator plugin to eliminate gradients and vignetting

Processed using Astronomy Tools actions in Photoshop, specifically:

- Increase Star Color

- Select Brighter Stars (which were then masked and shrunken with Levels)

Final touches made in Lightroom, including color enhancements and range masking to adjust saturation levels and bring out more detail in the galaxies.