Is this 'blooming'?

[Whippy]

Whilst out last night, I tried to do a 10 minute expusure and this happened:

(click to enlarge)

As far as I'm aware, my Atik 16HR has vertical non-antiblooming but not horizontal. Is this blooming and if so, apart from lowering the exposure time how do you get rid of it?

Tony..

[ianporter13]

Tony,

it looks like your mount moved during the exposure.

the Atik shouldn't bloom, I have the Atik16 nad have never had andy blooming issues with exposure up to 20mins, I've never gone beyond that but I wouldn't expect it to bloom if I did.

Ian

[Paxo]

Tony,

I think if it was blooming you would have seen 'diffraction spikes' in both directions equally, and must agree with Ian that it looks like your mount has moved (steadily at that though).

Blooming is causded when light-gathering pixel exceeds its capacity to hold captured photons, the excess energy spills over into the adjacent pixel (or pixels, if the second pixel also fills to its capacity). This spillover produces a spike of light on every bright star in the image.

Steve.

[MikeD]

Definitely the tracking., look at the core of M51 it is not saturated and therefore would not bloom anyway.

looks like the mount stopped tracking at all near the end of the expouser could you have had a mount power failure?

Mike.

[Whippy]

Thanks gents , I'm pretty sure the mount hadn't been nudged as I make sure the table I use is well away from the mount. T'was still a bit windy though....tt

Definitely the tracking., look at the core of M51 it is not saturated and therefore would not bloom anyway.

looks like the mount stopped tracking at all near the end of the expouser could you have had a mount power failure?

Mike.

Possibly Mike, the autoguiding died at some point last night and that needed restarting, it could have been then. It's all a bit blurry tbh!!

Either way, I'm glad it's not the cam as that would have worried me a touch!

Tony..

[centroid]

I concur with the other guys Tony, that's not 'blooming'.

Don't think it was 'tracking' as the stars would be elongated sausages, and if you didn't physically nudge the mount, then I suspect the wind did, as that's exactly the effect that I see if a gust 'hits' the scope.

Dave