Markarian's Chain (Stage 2)

[Carole]

Grabbed a further 55 minutes on this at Blacklands, but was so excited about being able to find M20, forgot to do any darks, so had to estimate and take them from my darks library.

This is a combo of Herstmonceux (posted last week) and Blacklands
total 2 hours and 20 minutes
I think the SNR has improved and the satellites are fading but I gained an extra one  

Link to the stage 1 version:
http://forum.orpington-astronomy.org.uk/index.php?topic=7567.0

28 x 300secs 800 ISO, Modified Canon 450D (no CLS filter at either)
WO Megrez 72 APO - guided PHD and QHY5

Slightly different crop as I didn't get them lined up exactly

Link to enlarged version in the gallery
http://gallery.orpington-astronomy.org.uk/albums/userpics/10047/Markarian_Chain%2C_%28Combo%29_Herstmonceux_and_Blacklands_total_28_x_5mins_800_ISO.jpg

[MarkS]

That's looking better Carole.  I think you've already realised this is actually a quite a tough target ...

Mark

[Carole]

Thanks Mark,

I think you've already realised this is actually a quite a tough target

Yes, I am but will persevere.

Carole

[RobertM]

Carole, is the focal reducer distance correct ?  Normally the star shapes are pretty good on those SW correctors even to the edge but I've noticed you have a few small seagulls towards the corners.

The image is certainly coming along nicely but it's a difficult subject so you're going to need a lot of subs (and patience) for this one.

Robert

[Carole]

you have a few small seagulls towards the corners.

Hi Robert, that made me laugh - seagulls - I have been calling them daggers.  

Yes already had this conversation with Mark and seems he had the same problem with his ED80.  I did try putting an extra spacer in once - Ian King kindly lent me one to try, but it made things even worse.

Normally I don't use the whole field so it doesn't show up, but this being a large object gives away my problem.

I'm actually thinking of getting rid of this telescope, so won't go to too much trouble trying to resolve it.
It's a WO X.08 Flattener III which came with the telescope. 

Carole

[RobertM]

Seagulls is, I believe, the correct technical term 

[Carole]

Well that's a new bit of terminology I have learnt then.