Messier 63 Sunflower galaxy is somehow an iconic object. Once you saw it, you probably will not forget it. It is a spiral galaxy with no central bar feature and moderate wound arms. There are not many large structures present in visible light, so the galaxy seems to contain much detail. But in infrared light large, symmetric, two-arm structure is seen. M63 is a prototype for a class of flocculent spiral galaxies. A large number of patchy and discontinuous arms are the opposite of grand design spiral galaxies.
Messier 63 is located in the constellation of Canes Venatici. Was first discovered by Pierre Mechain. It was also on the list of first galaxies with identified spiral structures – in the mid-19th century by Lord Rosse. M63 Sunflower is about 29 million light-years away from us. It interacts gravitationally with well known M51 galaxy. Outer regions of M63 rotate so quickly, that would rip themselves apart if there were no dark matter that glues it all together.
I have captured luminance data for this image in April 2020, and RGB color channels in May 2020. It was the first time I actually imaged this galaxy. I always waited for better conditions, better transparency, and seeing. M63 contains a lot of small-scale detail, so seeing is crucial to record it. But at the same time, it also contains a large halo and some faint outskirts, so it requires both good transparency and a long exposure time. It is a beautiful but demanding astroimaging target. I collected 550 minutes of luminance exposures and 200 minutes of RGB data.
There were a few really transparent nights in April 2020 at my location, so even under the suburban sky, I was able to capture some faint details. But the seeing was not perfect, it oscillated around 2.5-2.8 arc seconds. So the amount of detail in this amazing object is not as large as I wanted it to be. But it probably will never be 🙂
Image technical data: Date: 18 April - 21 May, 2020 Location: Nieborowice, Poland Telescope: Meade ACF 10" Corrector: AP CCDT67 Camera: QHY163M, gain 100 Mount: SW EQ6 Guiding: Evostar 72 + ASI290MM Exposure: LRGB 375x2 minutes Conditions: seeing medium, transparency good
