M101 - Pinwheel Galaxy

[matt_baker]

M101 - The Pinwheel Galaxy

M101 is a face-on spiral galaxy 21 million light-years away from Earth in the constellation Ursa Major. It was discovered by Pierre Méchain in 1781 and was communicated that year to Charles Messier, who verified its position for inclusion in the Messier Catalogue as one of its final entries.

Equipment: 
TS Optics 90mm CF Triplet APO
Skywatcher HEQ5 Pro (Belt Modded)
ZWO 1600MM Pro 
ZWO 8 Position 31mm Filter Wheel 
ZWO LRGB Filters
ZWO EAF
QHY5L-II M & 50mm Guide Scope
Remote controlled with Stellarmate RPi 4

Acquisition:
115x90" L
20x180" R
20x180" G
20x180" B

Processed in PixInsight

Not sure what's causing the purple fringes considering it's a triplet. Have done RGB before with this setup but didn't experience it this badly. Maybe a couple of bad frames that made it into the stack?

AstroBin Link:

https://www.astrobin.com/full/o3nstc/C/?nc=user

[GiorgioF]

Really excellent result! Could you post a light without crop? Just to understand the dimension of the subject in the frame.

 

[Ouroboros]

Lovely image. I can’t see the purple fringes on my iPad screen. 

[matt_baker]

11 hours ago, GiorgioF said:

Really excellent result! Could you post a light without crop? Just to understand the dimension of the subject in the frame.

 

Of course, will do when I get home as the pubs are finally open here in England

 

11 hours ago, Ouroboros said:

Lovely image. I can’t see the purple fringes on my iPad screen. 

Thank you! I've got more data in the last couple of nights so I'll be adding that and hopefully get a better result

[Craney]

10 minutes ago, matt_baker said:

Of course, will do when I get home as the pubs are finally open here in England

Careful things don't spiral out of control.  

Great pic btw.

[teoria_del_big_bang]

Great Image, Colour looks good to me.

I got some LRGB data lat night on this as there was no moon about seemed a good time to do it but I need a lot more data 🙂 

Steve

[matt_baker]

4 hours ago, Craney said:

Careful things don't spiral out of control.  

Great pic btw.

 

4 hours ago, teoria_del_big_bang said:

Great Image, Colour looks good to me.

I got some LRGB data lat night on this as there was no moon about seemed a good time to do it but I need a lot more data 🙂 

Steve

Thanks! Just processing last night's data now so I'll update when I'm finished

[matt_baker]

Added 2.5 hours more L and filtered bad frames in RGB. Will add Ha soon. Decided to also not drizzle this time to see the effects 

 

[matt_baker]

Complete reprocess along with adding in 2.5 hours of Ha bringing it to 11.5 hours in total.

Full acquisition now:

Ha: 31x300", L: 229x90" , R: 24x180", G: 22x180", B: 21x180"

Pixel scale is 1.61" Per Pixel, but nice to see how much detail I could recover with Decon and sharpening

Ha taken with Gain 200 Offset 50

LRGB taken with Gain 76 Offset 15

Have included two - one cropped and one wider. Will attempt the drizzled set and compare the differences

Any questions or comments on areas of improvement would be greatly appreciated!

Edited April 18, 2021 by matt_baker