Messier 51 (Canes Venatici)
Fig. 1 - One of the most photogenic galaxies of all: The spiral galaxy Messier 51 in Canes Venatici, photographed with an 8-inch f/5 Newtonian reflector on a ZWO AM5 mount.
| Object name: | Constellation: | Coordinates: | Apparent size: | Visual brightness: |
|---|---|---|---|---|
| Messier 51 (NGC 5194) | Canes Venatici | 13h30m / +47°12' | 11.2' x 6.9' | 8.4 mag |
The interacting spiral galaxy Messier 51 (NGC 5194, "Whirlpool Galaxy") in the constellation of Canes Venatici. It was the first galaxy to be classified as a spiral galaxy and has two very prominent spiral arms that wind clockwise. The pronounced spiral structure of the Messier 51 is believed to be the result of the close interaction between it and its companion galaxy NGC 5195, which may have passed through the main disk of Messier 51 about 500 to 600 million years ago. Messier 51 is the brightest galaxy in the M51 Group, a small group of galaxies that also includes M63 (the Sunflower Galaxy), NGC 5023, and NGC 5229. The Whirlpool galaxy is 31 million light-years from Earth and 76,900 light-years in diameter. It was discovered by French astronomer Charles Messier in 1773 (source: Wikipedia).
Exposure time: 5h 24min (108x3min) at gain 100 and -10°C, taken on May 19 and May 29/30, 2025. Processing with Astro Pixel Processor (APP) and Photoshop. Darks, flats, bias and darkflats were used.
Equipment: Cooled ASI 2600MC Pro camera, TeleVue Paracorr Type II coma corrector, 8" f/5 "ONTC" Newtonian telescope riding on a ZWO AM5 Strain Wave Mount, ZWO OAG-L off axis system, ASI 174MM Mini guide camera, ASIAIR Plus.
Fig. 2 (see below) is a labeled image of Messier 51. When viewing the image, the eye moves from the prominently bright foreground star HD 117815, located 400 light-years away, to other stars of our own Milky Way, which are likely a few hundred to a few thousand light-years distant.
Since our Milky Way is not very dense in the photographed direction, we are able to look beyond our galaxy into the depths of space and recognize the picturesque galaxy Messier 51, which is 31 million light-years away. Additionally, several galaxies from the IC catalogue (Index Catalogue of Nebulae and Clusters of Stars) are visible (IC 4263, IC 4277, IC 4278, and IC 4282), already located at distances of 100–600 million light-years from Earth. The galaxy cluster Zwicky 6057 and some PGC galaxies in the image are more than a billion light-years away.
Fig. 2 - Labeled version of Messier 51. The galaxy cluster Zwicky 6057, several IC galaxies (IC 4263, IC 4277, IC 4278, and IC 4282) and an abundant amount of PGC galaxies are in the same field of view. Zwicky 6057 is thought to be 2 billion light-years from Earth, some of the PGC galaxies are 1 billion light-years away, while the IC galaxies are believed to be 100-600 million light-years from Earth.
Fig. 3 - Search chart for Messier 51. Copyright 2025 'The Mag-7 Star Atlas Project', www.siaris.net.