M101 The Pinwheel Galaxy

Well, as our  blackheath event was cancelled last night, I thought I work on stacking my images from the night before as I described on the "...whats on Sky" thread.   Two objects I aimed for imaging-wise, until the clouds finally made an appearance at 6am in the morning, dark they were too as it suddenly bloody poored down on me as I frantically covered my scopes with my rain sheets.   What a funny little Isle we live on!  It was time to go to bed anyway.  I was at a nice b&b in Lynsted with decent skies, will go there again.

 

So anyway, M101 was my target as I felt it a nice progression as I space travel onwards from Bode's Nebula (12 million light years away) to this one, 21 million light years away.  I guess watching Cosmos series recently where Neil Tyson (and Sagan before him) visits all these cosmic landmarks in their "Spaceship of the Imagination", so I feel like I want to do the same thing and keep going further out!

 

 

https://flic.kr/p/CPiJEY

 

I used my field Flattener for the first time that I bought a year ago (yeah, there is a lot of stuff I buy that I dont use until a year or 2 later!) under Rupert's advice when he noticed my Andromeda stars were stretched at the edges.   And sure enough it really works, stars are nice and round right at the edges.  And most welcome too because even though I could crop the images, I would have lost those other galaxies that show up in the image.  And wow, I can see about 11 galaxies surrounding M101.   I guess that's the nice thing about imaging with a wider field 80mm refractor.  I do still want to get more detail from the M101 with my 8" SCT  though but of course that would be at the sacrifice of losing that scope of the deep field view.   I'm reading up on all those other galaxies I am seeing in this picture.  They are mostly dwarf galaxies, all companions of the M101.  That large fuzzy object at the bottom edge is an interesting one, NGC 5474, its being distorted by the pull of M101 and so its nucleus pulled towards M101 while its spirals linger below it.  Shame I couldnt catch this more clearly and fuller into the frame.  If I knew about it while imaging this, I would have framed it differently.  But there is another galaxy near the top of the frame (NGC 5422) which is not a dwarf but another galaxy in the cluster and is 80 million light years away.  And another one top right, NGC 5475.  I dont know how far that one is, I cant find more detailed info on it.  What is the best website to look up definitive stats on these distant galaxies?  I'd love to know how far that particular one is.

 

In terms of the colour processing on this image.  Its a little much green, isnt it?  I dont know why my stacking comes out quite so green shifted but naturally I adjusted the RGB levels but when I do that, I noticed the galaxies are not so distinguishable.  So I deliberately left it very slightly green shifted (and saturated) so that the galaxies are easier to spot!!  And for me, personally, I quite enjoy this interpretation and purpose for this image.   The larger dwarf galaxies dont have that green tint but they are easily spotted due to their fuzziness anyway.  I see so many different colour interpretations on the internet, so can I not get away with this one?

 

I am happy with my polar alignment that night.  I was getting 4 minute clean exposures but not always consistent.  So I reduce it to 3 minutes exposure frames which all came out consistently sharp.  I did one hour worth at ISO 1600 and then another hours worth at ISO 3200.  I didnt realise DSS stacks multiple ISOs, I thought I was just going to end up with two different stacked images but DSS seems to have stacked them all together.   I made sure to take dark and bias frames this time and that really makes a difference when compared to my really noisy Bode's Nebula last month.

 

Well, as the Backheath event is also cancelled for tonight, I might as well work on my comet now...but that looks very disappointing as I can hardly see the tails 🙁

 

 

 

Image specs:

Unguided

21 X 180 sec ISO 3200

21 X 180 sec ISO 1600

(2hrs 6mins total exposure)

16 dark frames

41 Bias frames

 

Image captured with a Dell Ultrabook using Canon Utilities software.

 

Stacking:  Deep Sky Stacker (adjusted RGB, saturation and levels)

Post Processing:  Photoshop (basic levels and curves with gradient)

 

 

Equipment:

Scope: Skywatcher Equinox 80 APO refractor.

Mount: HEQ5 Pro Synscan mount

Camera: unmodded Canon 650D with a

Accessories: Field Flattener with a T mount screw,