The area around Messier 101 is loaded with galaxies. There are no less than 5 galaxies in this image, which represents 6.5 hours of integrated exposure time.
The Pinwheel Galaxy (also known as Messier 101, M101 or NGC 5457) is a face-on spiral galaxy 21 million light-years away from Earth in the constellation Ursa Major. It is a textbook example of a “Grand Design” spiral galaxy, where the spiral arms wind around the galactic nucleus. M 101 is significantly larger than our own Milky Way galaxy, with a diameter of 170,000 light years. It has many H II nebula regions, which appear in this image as reddish-pink patches in the spiral arms (captured with a Hydrogen alpha filter). M101 shines at magnitude 7.9
Lets look at M101’s friends in this image:
- NGC 5474 – (upper left corner) a peculiar dwarf galaxy, magnitude 10.8. This is another grand design spiral galaxy also lying 21 million light years away.
- NGC 5477 – (upper center) a dwarf galaxy located 20 million light years away from Earth, magnitude 14.
- NGC 5473 – (upper right) a lenticular galaxy located roughly 85 million light-years away, magnitude 11.5.
- NGC 5422 – (lower right corner) another lenticular galaxy located at a distance of about 100 million light-years. This island universe appears edge-on and shines at magnitude 11.9.
Click on the image to explore a larger version.
Image Info
- Imaged from the KPO field in Saint Cloud, Florida.
- Camera : ZWO ASI1600MM Pro
- Lens: Canon 100-400 f/5.6L lens, set to 400mm
- Mount: iOptron SmartEQ Pro
- Red: 10 subframes of 300s = 50 min integration
- Green: 12 subframes of 300s = 60 min integration
- Blue: 10 subframes of 300s = 50 min integration
- Luminance: 34 subframes of 300s = 170 min integration
- Hydrogen Alpha: 12 subframes of 300s = 60 min integration
- Total integration time: 390 min = 6.5 hours.
- Captured via ASIAir Pro automation
- Optical tracking via ASIAir automation, currently using ST4 mount control via the ASI120MM-S guide camera
- Separate channels stacked and HaLRGB integrated in Astro Pixel Processor, and processing for light pollution sky fog removal
- Image cropped, stretched, and noise processed in Nebulosity.
- Final processing in Aperture
- Annotations done in PhotoShop