- The Pinwheel Galaxy is a face-on spiral galaxy, located 21 million light-years away from Earth in the constellation Ursa Major.
- M101 is a large galaxy, with a diameter of 170,000 light-years while our Milky Way has a diameter between 100,000 and 120,000 light-years.
- It has a disk mass on the order of 100 billion solar masses.
- It has a small central bulge of about 3 billion solar masses similar to Andromeda.
- M101 has a high population of H II regions, many of which are very large and bright.
- H II regions are ionized by large numbers of extremely bright and hot young stars; those in M101 are capable of creating hot superbubbles.
- 1,264 H II regions were cataloged in the M 101 galaxy in a 1990 study.
- Three prominent enough received New General Catalogue numbers: NGC 5461, NGC 5462, and NGC 5471.
- M101 is asymmetrical due to the tidal forces from interactions with its companion galaxies.
- In 2001, P98, located in M101, was identified as an ultra-luminous X-ray source more powerful than any single star but less powerful than a whole galaxy—using the Chandra X-ray Observatory.
- In 2005, Hubble and XMM-Newton observations showed the presence of an optical counterpart, strongly indicating that M101 ULX-1 is an X-ray binary.
- The M 101 black hole is just 20 to 30 solar masses, and consumes material (including captured stellar wind) at a higher rate than theory suggests.
- M101 has about 150 globular clusters, almost same number of the Milky Way's globular clusters.
- M101 has six prominent companion galaxies: NGC 5204, NGC 5474, NGC 5477, NGC 5585, UGC 8837 and UGC 9405.
- Several supernova events are reported since 1909.
- On August 24, 2011, a Type Ia supernova, SN 2011fe, initially designated PTF 11kly, was discovered in M101. It had visual magnitude 17.2 at discovery and reached 9.9 at its peak. Type Ia supernova, occurs in binary systems in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white dwarf.
- On February 10, 2015, a luminous red nova known as M101 OT2015-1 was discovered in the Pinwheel Galaxy. Luminous red nova is a stellar explosion thought to be caused by the merging of two stars and characterized by a distinct red colour, and a light curve that fades slowly with resurgent brightness in the infrared. https://en.wikipedia.org/wiki/Pinwheel_Galaxy
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It has been a project that for some reason has cost a lot to finish. Not because of the data. Maurizio did a pretty good marathon session in March 2021.
Start by processing the data in parts, first the one made with the L-Pro filter, both in DSS and Siril, normal and 2drizzle.
Then all the sessions done with the Enhance and Extreme filters, both normal and 2 drizzle.
In a normal result in Siril, HGT was applied testing that new Siril tool.
I also did the extraction of Ha and [OIII] to use that information as luminance and highlight the HII regions that the galaxy has.
The galaxy was worked in a starless way, taking care that in the process the HII zones of the galaxy were not left out, which had to be reinserted again with a mask. Applied in Raw Camera: clear, dehaze, texture, white in addition to smart sharp and Noise Exterminator and Denoise at various low levels.
It was quite laborious to make the final assembly of all the results obtained, processed individually in the final combination, but it was achieved, in addition to applying a percentage and blending 'modality' to each one when it provided what I liked.
On more than three occasions I restarted the whole process from the beginning as I didn't like what I got and for some reason the internal details of the galaxy didn't emerge properly even though they were there.
Despite all the good will, although the result is satisfactory, I hope to try a new processing with another scheme later and be able to compare results.
Thank you for visiting us and seeing our work and happy to receive comment on it.
Processed August 2022
https://twitter.com/AstroOtus/status/1563521092085436418https://twitter.com/AstroOtus/status/1563521099161251842
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