M52 Up close and personal.

[Paul M]

Having got a clear spell in the early hours of today, I got to image my intended target, Nova Cas 2021.

I spotted M52 in the guider subs and decided to go there next. 

I was using my Mak 127 and ASI178MC camera. Not a match made in heaven. Plate solving reports a F/L of 1362mm so oversampling. TBH I played around with 2x2 and 3x3 binning but the only benefit seemed to be smaller file sizes. So I stuck with 1x1 binning. 

12 x 120 sec and 5 x dark frames to kill off that awful amp glow. I was going to leave it just taking subs and go to bed but at 03:30 the clouds rolled in so i rushed a few dark frames and dragged it all indoors. No light flats, was thinking about doing some today but life got in the way. I stacked in DSS and fettled in PS. Not a nice image so I let ASTAP do it's thing, untouched by my hand. This is uncropped! Glad my mount guides nicely  Looks like a lot of dust starting to gather on the cameras optical window too.

I miss diffraction spikes!

 

Edited March 30, 2021 by Paul M

[vlaiv]

What a nice collection of space marbles

Do you have any idea why this happened? Maybe out of focus + spherical because of mirror spacing + low down on horizon so atmospheric dispersion?

[Paul M]

Well spotted!

The Celestron Mak127 is a nice little scope and visually very nice to use but ive had big stars from the ASI178 camera with both this scope and the 250 Newt.

Some of it is down to my processing talents or lack thereof  The colour effects are caused by ASTAP. I did a stack in DSS but messed it up in PS.

As for the image above, I spent ages focusing and refocusing using the magnifier tool and the focusing aid in APT. Never did I feel the focus was sharp. Event faint stars were spread over many pixels. So the above image really is as good as it gets with that set up, as confirmed by similar results on other targets on different nights.

It's not my specialist field but I've always felt this camera is better suited to short focal length scopes.

I get sharp stars with my DSLR on both scopes. 

I really chose that camera because I thought it would be good for the opposition of Mars last year but I barely got to look at that.

Anyway, I set up with the big gun last night hoping to make some comparisons using my new to me Optolong L Pro filter which much might reduce any dispersion effects. The weather God's had other plans!

Ultimately I need/want a different camera. I even went back to my DSLR a while ago but it's not astro moded. Maybe I'll look at that as an option.

So in answer to the question,  I'm blaming the camera! 😎🤣

 

Edited March 31, 2021 by Paul M