What is the green smudge?

[Eruliaf]

So after some decorating I decided to see if the new scope/mount I purchased was any good and took it outside. I set it up incredibly quickly so not a good polar alignment, but manged to do a 2 star align quite well. (130PDS and HEQ5 from ebay!)

Anyway, I took the following photo of Arcturus and the green smudge appeared next to it. I took about 20 images and the smudge moved out of centre as the images progressed.

I have an unmodified canon 600D with a skywatcher coma corrector.

Any ideas?

[Sunshine]

Interesting, I cant say for sure but, upon closer inspection I can see the diffraction spikes within the smudge which perfectly match the same as the star, something on the coma corrector maybe?. Looks like some species of lens flare, and judging by what you say how it moved id be inclined to say lens flare of some kind.

[Eruliaf]

Thanks for the reply. Do you think it would be related to the coma corrector or can this be the scope?

[vlaiv]

47 minutes ago, Eruliaf said:

Thanks for the reply. Do you think it would be related to the coma corrector or can this be the scope?

Quite easy to check - remove CC and try on a bright star.

I would say it is CC related, but best give it a try without it to verify

[Adam J]

On 11/04/2019 at 23:21, Eruliaf said:

So after some decorating I decided to see if the new scope/mount I purchased was any good and took it outside. I set it up incredibly quickly so not a good polar alignment, but manged to do a 2 star align quite well. (130PDS and HEQ5 from ebay!)

Anyway, I took the following photo of Arcturus and the green smudge appeared next to it. I took about 20 images and the smudge moved out of centre as the images progressed.

I have an unmodified canon 600D with a skywatcher coma corrector.

Any ideas?

It you have a SW 0.9 coma corrector then it is a reflection, that coma corrector is known for it. Should not give you too much trouble though as it only happens on bright stars.