3I/ATLAS

[swift echo]

It’s moving quite a lot

[proven beacon]

I see images of the comet and ask myself a question why the stars are trailed. It is possible to do an image with stars not trailed

[void marten]

Very cool!

[swift echo]

Yes it is

But then the background is a bit more noisy because you basically stack two finalized light frames

[proven beacon]

In case if the star field does not have a major object and it is only stars, you can denoise it a bit more. When you have a major object, it is more complex as you want to consider relation between comet and the object and it is imaging two major objects at the same time.

I did recently 3I/Atlas as well

[swift echo]

So you worked more with masks to denoise it?

[proven beacon]

Oh no… I worked with comet and star field as separate images. For comet I removed stars and aligned on comet only. For star field I removed comet and aligned on a reference star image. Reference image for stars and comet is the same. It gives you real picture.

[swift echo]

That is exactly what I did in the second one