Photograph · May 3, 2022
The Whirlpool Galaxy
The Whirlpool Galaxy is a face-on spiral galaxy roughly 25-30 million light-years away interacting with its smaller companion galaxy.
As we move into May, the Deep Sky season is drawing to a close until autumn brings dark nights back to Denmark again.
The final image for now is this one of the Whirlpool Galaxy (M51) and its “little brother”, NGC 5195. You can find them by looking in the direction of Alkaid, one of the brightest stars in the sky and part of the Big Dipper. At an estimated distance of around 25–30 million light-years, however, the galaxies are quite a bit farther away!
The two galaxies are fascinating not only because M51 is beautifully oriented towards us, and both large and bright enough to be a favourite target among astrophotographers, but also because they provide a striking example of interacting galaxies. Today, NGC 5195 lies “a little” behind M51, but computer simulations suggest that, from our point of view, NGC 5195 originally approached from behind, passed through the central region of M51, and was then pulled back through M51 again — the so-called “multiple encounter” model.
Capturing the image
The image was captured using LRGB for colors and contrast combined with Ha for more details in the galaxy’s hydrogen clouds.