It’s Galaxy Season (and a surprise in Hercules)
It’s Galaxy Season (and a surprise in Hercules)
Amateur astronomers know that the best time of the year to capture images of distant galaxies is between March and May. This is because during its orbit around the Sun our planet is pointing to a part of the sky where many other galaxies, far beyond the Milky Way, are visible.
On the night of April 17, 2022, despite the (almost) Full Moon and the light pollution (I live in a Bortle 8 area), I imaged two iconic galaxies: the Whirlpool Galaxy (Messier 51) and the Sunflower Galaxy (Messier 63).
Setup
Scope: Celestron 8 SCT
Focal Reducer / Corrector: Celestron 0.63x Focal Reducer / Corrector (203mm aperture and 1279mm focal length)
Mount: Celestron AVX mount
Imaging Camera: ZWO ASI533 MC PRO (cooled at -10°C)
Filters: Optolong L-Pro (light pollution filter)
Guiding camera: ZWO ASI224 MC with a IR Cut filter, PHD2
Guide Scope: Orion Deluxe Mini 50mm Guide Scope.
Software: NINA, PixInsight, Topaz Denoise AI
The beautiful Whirlpool Galaxy (M51) is one of the most photographed galaxies. With a distance of 23 million light years, it is located in Canes Venatici (not far from the Big Dipper). For observers above 43°N latitude Messier 51 is circumpolar (it never sets below the horizon). I added the annotated image with PixInsight.
The total integration time for Messier 51 was 48 minutes (16×180 secs., dark, flat, bias). Some fine details are visible:
- The dwarf galaxy NGC 5195, which is interacting with the Whirlpool Galaxy;
- NGC 5198, an elliptical galaxy visible as a little oval to the right of NGC 5195;
- IC4278 is another galaxy, with an apparent magnitude of 15.39.
Note: Scroll the slider to switch between the images with and without annotation.
The Sunflower Galaxy (M63) is a spiral galaxy located in the constellation Canes Venatici. It was discovered on June 14, 1779 by the French astronomer Pierre Méchain (Charles Messier’s friend and colleague). It was added to Messier’s catalog along with 23 more objects discovered by Méchain. Its distance is about 27 million light-years from Earth and it is estimated to have over 400 billion stars!
The bright yellow central disc with short spiral arm segments, starburst areas and dust lanes give it its name of the Sunflower Galaxy.
The total integration time for Messier 63 was 60 minutes (20×180 secs., dark, flat, bias).
To complete my imaging session, I captured the Great Globular Cluster in Hercules (Messier 13), which was getting higher in the sky after midnight. Its apparent magnitude is 5.8 and can be spotted with the naked eye under a dark sky.
Located 25,000 light-years from Earth, it was discovered in 1713 by the English astronomer Edmond Halley (known because he recognized the periodicity of the comet that has his name). It’s home of over 100,000 stars!
Fun fact: On November 16, 1974 the Arecibo radiotelescope sent a message at the current location of M13, to potential extraterrestrial civilizations.
From Wikipedia: “The Arecibo message is an interstellar radio message carrying basic information about humanity and Earth that was sent to globular star cluster M13 in 1974. It was meant as a demonstration of human technological achievement, rather than a real attempt to enter into a conversation with extraterrestrials“. The message will take 25,000 years to get there, and we will have to wait 25,000 years to get a potential response!
Since Messier 13 is a very bright object, I had to take several short exposures (10 seconds) as long exposures could blow up the bright stars. The total integration time for Messier 13 was 11 minutes and 20 seconds (68×10 secs., dark, flat, bias).
When I processed the image with PixInsight, I noticed that I captured a distant spiral galaxy (IC4617), 489 million light years distant. Light has traveled almost half a billion years from this distant galaxy to reach our eyes!
Note: Scroll the slider to switch between the images of M13 with and without annotation.
