horsehead stars??

[iwols]

hi all just processed the above with astropixel and was wondering about the stars with 4/5 in a line scattered about the head?

[souls33k3r]

My money is on either the channels have not been aligned properly AND/OR the darks did not get subtracted

[tooth_dr]

I get this when I dont check sigma clipping on the integration tab.  Try that and see what happens.

[geordie85]

Looks like stacked hot pixels. 

[dannybgoode]

I have this in my image. First thing I’m going to rule out is the cobwebs I spotted in the tube!

If that doesn’t sort it then I’ll go start looking at darks etc

[iwols]

thanks guys not using darks ,when i used sigma clipping it was ok but lost a lot of detail,ive uploaded my data if anyone wants to give it a go

https://www.dropbox.com/sh/33m97v87taykvg8/AABgn-u3oy18nGweUzaGpJfha?dl=0   so i can see how it should be

[iwols]

really need to improve my processing technique,i think,or do i need more data?

[ollypenrice]

I'd say it is what's called 'walking noise.' Hot pixels which are in a fixed position on the chip appearing in a different position on successive images. Even if you are guiding there can be field rotation due to imperfect polar alignment. (If you stack just an early and late sub, have a look at the position of their borders. These are likely not to align with each other for the same reason. During a single sub the field rotation will maybe not show but over the duration of a sequence it will do so.)

Either you need to re-do your darks or apply strong hot pixel filtration before combining. Strong sigma clipping should also help.

Olly

[tooth_dr]

4 hours ago, iwols said:

thanks guys not using darks ,when i used sigma clipping it was ok but lost a lot of detail,ive uploaded my data if anyone wants to give it a go

https://www.dropbox.com/sh/33m97v87taykvg8/AABgn-u3oy18nGweUzaGpJfha?dl=0   so i can see how it should be

I would love to have a go at this data. I’ll get a look tomorrow and see what it looks like. 

[iwols]

2 hours ago, tooth_dr said:

I would love to have a go at this data. I’ll get a look tomorrow and see what it looks like. 

Thanks Eagerly Await The Outcome

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