Jupiter near opposition with a 10" f/5 Dobson

[sebgod]

https://nova.astrometry.net/image/11983681 during this bad weather im going through some of the stuff from last year. This was taken near opposition with a 10" f/5 Dobson and a 2.5 Barlow , hand guided. Given that I had to recenter several times I think I might actually have to derotate the images is that correct? What is the longest time one can get away without doing that?

[sebgod]

This is the image: 287464

[rustigsmed]

nice work sebastian - recentering won't necessarily cause the need for derotation.

It is more the length of time you were capturing Jupiter for due to the planet's fast rotation and also the alt azimuth nature of mount as it moves jupiter slowly appears to rotate in the field. I capture my planets on a dob too but don't need to worry about the alt azi field rotation too much, you can use the program winjupos if you would like to derotate images (from long data sets).

[Dave882]

Jupiter has a fast rotation that will cause blurring of the image. I find that there is some rotational effect after 60-90sec but you can get away without de-rotating for captures up to 3-5min and still get a decent image.

That’s a quite a decent image by the way- perhaps some wavelet work in Registax would help bring out some more detail if you haven’t already.