M51 with intermediate luminosity red transient

[MarkS]

Taken last night here is a very quick processing of M51 with an intermediate luminosity red transient (ILRT).   This one goes under the name AT 2019ABN.  It suddenly appeared earlier this year and was a supernova candidate.  Some references call it a luminous blue variable (LBV) but it's definitely not blue!

It was discovered on 22-Jan by ATLAS (Asteroid Terrestrial-impact Last Alert System). 
Further info here: http://www.rochesterastronomy.org/sn2019/sn2019abn.html

Modified Sony A7S on Celestron C11 with 0.72x reducer/corrector.  345 x 30sec subs giving nearly 3 hours of data.  I stacked the sharpest 345 subs out of 440.



Mark

[Carole]

Great stuff Mark, and I see you have the nice brown area on the smaller galaxy that you said once before that you were struggling to get.

Carole

[MarkS]

Great stuff Mark, and I see you have the nice brown area on the smaller galaxy that you said once before that you were struggling to get.

Carole

For once, everything came together last night as the moon began to set.  The wind died, the ambient temperature stabilised, transparency was good, seeing was good, the best guiding I've had for ages (0.5 arcsec RMS) and the best ever SQM reading (21.28) I've recorded here at home.

Mark

[Hugh]

Stunning!  Are these galaxies interacting or is it just alignment?

Hugh

[RobertM]

I agree Hugh, stunning - excellent scale, detail and lovely colours.

Robert

[MarkS]

Thanks Carole, Hugh, Robert.

I should re-iterate that I processed this in a quick and dirty manner just to show the ILRT.

M51 and its interacting neighbour NGC 5194 is one of my favourite all-time subjects, which is why I keep coming back to it.

It was the first subject I took with the Starizona 0.72x large format corrector, this time last year:
http://forum.orpington-astronomy.org.uk/index.php?topic=11328.msg82330#msg82330

I hope to grab more data after Easter and combine it all together to reduce image noise.

The Starizona corrector does a very fine job but the C11 still suffers from flop in the primary mirror, which has 2 main consequences:

• I need to recollimate when moving to a different part of the sky
• When taking flats, the scope must be pointing at exactly the same part of the sky as shooting the light frames

Compare this with the Tak Epsilon 180ED where I can slew to any part of the sky at any time and produce a pin-sharp image.

Mark

[The Thing]

Another fine image Mark, a most suitable image scale as well, can't wait to see the final version some time soon. Last night was great, very clear air after the moon had gone. I have had a close look at my recent M51 and I can just see the object, it's only a pixel or two on my version. Fascinating to think it's a new feature of indeterminate origin. I also had a look at Rogers version but the image scale is too small.

[Carole]

I need to recollimate when moving to a different part of the sky
When taking flats, the scope must be pointing at exactly the same part of the sky as shooting the light frames

What a PITA!!

I had to look up AT 2019ABN as I thought it was a supernova, but find it is a supernova impostor.  Never heard of these before, makes interesting reading, so thanks for the heads up.

Carole

[NoelC]

Very good Mark
wonderful subject too.
Noel

[MarkS]

I need to recollimate when moving to a different part of the sky
When taking flats, the scope must be pointing at exactly the same part of the sky as shooting the light frames

What a PITA!!

I naively bought a C11 as my first imaging telescope and didn't really understand the problems I was hitting.  I gave up and started using an ED80 instead and couldn't believe how easy it was!  I then bought the Tak Epsilon.  Now I'm a lot more experienced, I'm taking on the C11 again.  But I think eventually I'll end up getting something like a Ritchey Chretien which has a fixed primary.

Mark