Cloudy with a touch of supernova

[AKB]

Clear Outside has been showing solid red for the week ahead, so last night I was marginally surprised (should not really have been so) to actually see some stars.  I've been very keen to give Jocular a live run (it has been so long!)  The front-end acquisition is done with Nebulosity on the observatory PC, networked to an indoor iMac, with a shared disc, running Jocular.

I lined up M92, because there was a brief gap in the clouds, and gathered 11 x 10 seconds, and whilst M92 may not be an EEVA 'target of choice', my subsequent annotated plots show some galaxies at the edge of the capture NGC 6329, 6332, and 6336.  Thanks also to Pretty Deep Maps, I can identify PGC 2223204 (mag 16.5).

But never mind that, I glimpsed Mars and recalled that NGC 514 with its supernova was nearby, so turned to there and just let Jocular collect 20-second frames... 70 in all, nearly 60 of them being clouded out.  The Atik 460EX generates about 6 Mpixels, so that's 70 x 12 Mbytes which, I'm very pleased to say, Jocular handled like a champ.  I posted a single frame here:

 

 

and here's Jocular's stack of the best 12, which I think is pretty good, for the circumstances. (SN is the bright apex of the triangle of stars pointing at the galaxy.)

Thanks to @Martin Meredith for much help in getting this going on my Mac.

Tony

 

Edited October 18, 2020 by AKB

[Martin Meredith]

Very good catch. I can see that it is still very bright. Would you believe I had this SN on my list for Friday and was so distracted by other interesting stuff I forgot all about it. Maybe tonight...

Thanks for beta-testing the new version of Jocular. I'm more surprised than anyone that it can handle 70 x 12M images in such a way that you can operate on them more or less in real time... but as a result I'm happy to have removed the former limitation to 2M pixels.

Its worth pointing out (to others) that the exposure info on the image is not going to be accurate in your use case, where the capture is performed by another program. The estimation process I use needs some refinement to better reflect the interval between subs arriving.

Martin

[AKB]

22 minutes ago, Martin Meredith said:

The estimation process I use needs some refinement to better reflect the interval between subs arriving.

In my case, the exposure time is in the FITS header. Although not perhaps universally the case, this may be a good starting point, before any more empirical method?

[Mike JW]

Hi folks,

At last I managed to get a clear spell to get a look at SN 2020 uxz in NGC 514. Desperation astronomy as I had to take many short subs and dump the wind rocked subs. My casual estimation is that the SN is now at about mag 13, maybe a touch brighter.

Pleased also that I picked up star forming regions in 514 and other details. At times I was looking through light cloud.

Mike

[AKB]

I had a go yesterday, but it was indeed a bit cloudy (and windy.)

This is 3 x 20 seconds @ 20:20  (I think the focus was good, but the clouds weren't!)

 

[Mike JW]

Worth having another look sometime to see if it brightening or fading. Mike

[Bill S]

Prompted by others observations and reports I decided to have a look at NGC 514 and SN2020uxz. Pleased that it showed up well. Marked it to clearly identify. The outer parts of the galaxy showed up and are easiest to see in the inverted snapshot.

 

 

 

 

I believe the supernova is a Type 1a - the one where a white dwarf accretes material from its binary companion until it reaches sufficient mass to explode. The critical mass and resulting supernova brightness are relatively standard so this can be used as a standard candle for distance measurement.

 

 

[AKB]

7 hours ago, Bill S said:

The outer parts of the galaxy showed up

Oh yes, nice galaxy!

[Mike JW]

Hi Bill, Glad you have had a clear slot to track down this SN and get some galaxy detail as well. It makes for a worthwhile outing. I kept meaning to remind myself what a type 1a is - thanks for the info.

As to 514 - intermediate spiral, with a bar and apparently there is plenty of star formation within the nucleus - classed as having a H11 nucleus.

Mike