M101 Pinwheel Galaxy

[Jkulin]

Well I collected a load of data last year and had to throw it all away because I couldn't get rid of some dust bunnies, so this year I was determined to get it right and hopefully have succeeded.

The processing was so critical that I despaired of ever getting an image that I could be proud of, it really tested me to the limit.

Link to more info: - https://www.astrobin.com/r4s23i/

Dates:May 27, 2020 ,  May 28, 2020 ,  May 29, 2020 ,  May 30, 2020

Frames:
Chroma Blue 2" unmounted: 8x780" -20C bin 1x1
Chroma Green 2" unmounted: 8x600" -20C bin 1x1
Chroma Ha 3nm: 8x1200" -20C bin 1x1
Chroma Luminance 2" unmounted: 21x600" -20C bin 1x1
Chroma Red 2" unmounted: 8x696" -20C bin 1x1

Integration: 10.8 hours

GSO/Altair RC 10" Truss, Moravian G2-8300 MkII, iOptron 120EC Mount, Chroma 2" LRGB & Ha Filters, Ultrastar Guide Camera

Here's the bumf: -

The Pinwheel Galaxy (also known as Messier 101, M101 or NGC 5457) is a face-on spiral galaxy distanced 21 million light-years (six megaparsecs) away from Earth in the constellation Ursa Major. Discovered by Pierre Méchain on March 27, 1781, it was communicated to Charles Messier who verified its position for inclusion in the Messier Catalogue as one of its final entries.

On February 28, 2006, NASA and the European Space Agency released a very detailed image of the Pinwheel Galaxy, which was the largest and most detailed image of a galaxy by Hubble Space Telescope at the time. The image was composed of 51 individual exposures, plus some extra ground-based photos.

On August 24, 2011, a Type Ia supernova, SN 2011fe, was discovered in M101.

Discovery

Pierre Méchain, the discoverer of Messier 101, described it as a "nebula without star, very obscure and pretty large, 6' to 7' in diameter, between the left hand of Bootes and the tail of the great Bear. It is difficult to distinguish when one lits the [grating] wires."

William Herschel noted in 1784 that "...in my 7, 10, and 20-feet [focal length] reflectors shewed a mottled kind of nebulosity, which I shall call resolvable; so that I expect my present telescope will, perhaps, render the stars visible of which I suppose them to be composed."

Lord Rosse observed M101 in his 72-inch diameter Newtonian reflector during the second half of the 19th century. He was the first to make extensive note of the spiral structure and made several sketches.

To observe the spiral structure in modern instruments requires a fairly large instrument, very dark skies, and a low power eyepiece.

[carastro]

That's come out really well John, love the Ha highlights.

Carole 

[Jkulin]

Just now, carastro said:

That's come out really well John, love the Ha highlights.

Carole 

Thanks Carole, that means a lot to me.

[tooth_dr]

Superb John, I like this version with the pronounced Ha areas.

[Jkulin]

Just now, tooth_dr said:

Superb John, I like this version with the pronounced Ha areas.

Thanks Adam, it was an absolute pain to get the Ha in, as every time I tried it kept saying the stars didn't align yet they all had the same reference image.

I finally closed it all down and recommenced from the RGB and Lum combo and then it worked, it was so bright that I had to reduce the Saturation down quite a bit, there must be so much Ha in that Galaxy.

[MarkAR]

Lovely image John, the 3nm Ha does look good and sharp.

[Jkulin]

6 minutes ago, MarkAR said:

Lovely image John, the 3nm Ha does look good and sharp.

Thanks Mark, out of any of my equipment the Chroma 3nm have proved themselves time and time again, best investment I ever made.

[Allinthehead]

That's a beauty John

[Jkulin]

2 minutes ago, Allinthehead said:

That's a beauty John

Thanks Richard, much appreciate your comment.👍

[tomato]

Great M101, the Ha has transformed the usual appearance of this galaxy.

[Jkulin]

35 minutes ago, tomato said:

Great M101, the Ha has transformed the usual appearance of this galaxy.

Thanks, yes when I added it it went bang, now sussed how to add Ha in PI, which I have failed miserably in the past to add.

[Jkulin]

This is just an example of how many instances I had open to try and get this right, and this was after so many different projects to get it the way I wanted: -

[Jkulin]

The more I kept looking at the image the more I kept noticing that the background was a little red, so a quick curve and I think it is now a lot better: -

What do you reckon?