7331 and Quintet with Laurin Dave.

[ollypenrice]

Stephan's Quintet and NGC7331 combining old data from my TEC with new from the dual TEC rig using Tom's TEC as well and Moravian camera belonging to Mr and Mrs Gnomus. The new data was captured and processed with SGL member Laurin Dave who also took me through deconvolution in PI on this one. Total integration: Luminance 33x15 minutes, colour 18x10 minutes per channel. Three hours per channel for the colour was a luxury so the idea behind this processing was to make the galaxies and faint fuzzies pop out of a tightly controlled starfield.  This comes at the expense of some faint IFN clearly present in the data. It will be interesting to try an entirely different approach making this a priority but IFN with tiny stars is never going to be easy!

Alan4908 posted an interesting link concerning the Quintet's small blue galaxy NGC7320, upper left in the group,  whose redshift puts it far closer to us than the other four of the Quintet. Like the galaxy to its right, which should be much further away, it seems to have a curving tidal tail. Why two parallel tails if they are not gravitationally connected? Radio data resolves the problem by demonstrating that the tail does not come from the spiral at all but from the interacting pair seen below it. 

Edit: We'll see if there's any Ha at the earliest opportunity.

 

Olly and Dave.

Edit: scroll down for a version (not very different! ) with the addition of 6 hours in Ha...

Edited August 9, 2019 by ollypenrice

[alan potts]

Wow, incredible shot from both of you, Dave told me he was coming down to you, he has been very helpful towards me, as indeed you have yourself, can't be easy putting up with halfwits like me when you are both so good.

Alan

[Petergoodhew]

That's got to be the best 7331+quintet I've ever come across Olly.  It's worth foregoing the IFN for this!

Interesting how things aren't what they seem.  I had always assumed the quintet were all together. You got some really good colours too - the three hours per channel were well worth it. 

Smashing job. Bravo.

[tomato]

Superb result, I love the detail, vibrant colours and the contrast with the star field ‘background’.

I agree it’s worth sacrificing the IFN for such a stunning image.

[ollypenrice]

With the moon around we decided to pop off some Ha for this one. Using both barrels of the dual TEC we collected 6 hours in 3 hours, which is always nice! It was very thin so getting it into play required pure thuggery but it was just about possible to do so... It only affects NGC7331.

 

Olly

 

[Tom OD]

Subtle effect but that’s what I like. Great job and well worth the night of Ha. 

Tom. 

[alan4908]

Very impressive Olly and nicely framed.

Alan

[old_eyes]

Astonishing image Olly. The value of collaboration! Many hands, cameras and processors.

[JamesF]

Lovely image.  I think there must be at least a dozen and a half galaxies visible there.

James