The hunt for supernova... 25.01.2014

[dawson]

Weather predictions all day looked to be OK from 21:00 though windy until 23:00, so I had planned to set up briefly just to have a look at the supernova (SN). The jet stream was right over head so I wasn't even going to bother with imaging Jupiter.

 

Left the C11 out on the mount this afternoon too cool down, and covered it back up with the Green Witch Bag luckily, as it was subsequently subjected to three more downpours!

 

At about 20:30 I went outside and it was crystal clear, and the wind was easing off; I knew baked beans were a bad idea earlier.

 

Re-checked the polar alignment and it was off a bit, so adjusted. Did a three star alignment, Sirius, Algol and Capella, pretty much bang on each time.
GOTO'd M82 straight away, wasn't in the field of view as far as I could tell, so I told the mount to go to Dubhe which was not in the field of view either. So do a new one star alignment and used Dubhe, then slewed to M82 and got it, pretty much bang on in the middle. Switched from the cheap and cheerful Meade 32mm Super Plossl EP I use for alignment, and put the 36mm Baader EP (77x mag) in to get a wide(ish) FoV look. I could see the cigar shape, quite faint and small, and I could see a definite white concentration to one side of its centre. I put the 17mm Baader EP (164x mag) in and got a much better view of the supernova, out to one side of the core of the galaxy.

 

I'd looked at the galaxy online before I went out and had worked out where the SN should be happening in relation to the centre of the galaxy and two very adjacent stars, but there was no need, it was barn door obvious where it was!

 

As the whole galaxy-SN complex looked quite bright, I decided I'd have a go and take a picture of it; never going to be able to compete with the likes of Ibbo, but I might be able to get a basic image showing the outline of the galaxy and the SN.

 

I put the CLS clip filter in the Canon 6D, and put it at prime focus on the scope. I slewed to a nearby star and with the Bahtinov mask sorted out the focus relatively easily. Then back to M82. Took some test shots at ISO 128000 to try and centre the galaxy best I could. The focus didn't look right so I played with it a bit more by taking an image then reviewing at 10x magnification on the LCD... Did some more test shots to see how long I could get before I was getting any trailing. It was still intermittently breezy; 60 seconds didn't work, but I think this was wind related; having just read the Pete Lawrence article on imaging M42 earlier in the day, he talked about 15 seconds upwards, so I plumped for 20 seconds to start with. At ISO 800 there was nothing to be seen what with the relatively dim subject, the CLS filter and such a short exposure; 1600 no better, 4000 was better but still not a great deal, so plumped for ISO 8000! Well, the camera is meant to have low noise so it was worth a try.

 

Did a few 20 second shots and reviewed them, and it looked ok. Set the intervalometer to do 100 of these and I went to put the kettle on.

Once I'd got a cuppa I took the binoculars outside, and sat on a high chair and had a nose around. M42 drew my attention first off to the west. I marveled at bright the nebula is, and how crystal clear it looked in the Helios naturesport 10x50 knockers (bought second hand from the treasurer of the Nottingham Astronomical Society for £20). Looked at the colour difference between Rigel and Betelgeuse and thought about the latter going supernova. Up to Aldebaran and the Pleiades and a nose around the Hyades; that is a fascinating cluster which I think is under valued.

 

Had a look at Jupiter and could easily see four of the moons, two on each side, one out on a limb (Callisto); again I was fascinated to see the planet and moons in such wide field view, and it was as though Jupiter was radiating light and illuminating the moons itself.

 

I scanned over to Castor and Pollux as I wanted to see if they'd both fit in the FoV and if so by how much, to work out the FoV of the binoculars. They did fit with some room to spare and I think the FoV is about 6 degrees.

 

Scanned over the southern horizon, and bumped into an open cluster... I had to get my bearings, as the bit of sky between Gemini and Leo isn't an area I have any knowledge about. I thought it must be Cancer and this was the beehive cluster (M44), as there was a star above and below slightly to the east. It was when I subsequently checked.

 

Over to Leo and the in the same field of view a bright blue star (Regulus) and a less magnificent yellow star (subsequently identified as 31 Leo); reminded me of Albireo from the summer.

 

Scanning further east I came across another pair of stars , again framed quite nicely in the binoculars; turns out these were Alula Borealis and Alula Australis in the tail of the great bear; the latter had been on my hit list to see if I could separate the double hidden there.

 

Back to the camera and it had done a load of images. Setting off doing some 40 second exposures for good measure. While it did those I had another cuppa and just sat again looking at the night sky with naked eyes. Wondered around the garden and thought again about having an observatory and the joy at being able to set up and pack away at the drop of a hat and not to have so much astro junk in the conservatory and on the dining room table... The I remembered the thunder and lightening earlier and how I'd tried to take some pictures of it, and how I'd set the camera to large jpeg files and not RAW!!!!! Ooops. Too late now; jpegs or nothing.

Put the telescope end cover on and shot some dark frames of the same duration as my data, then put a t-shirt over the end and pointed the telescope at the conservatory and turned the lights on and attempted to do some flat frames getting the white balance to about 50% on the histogram; thanks again Pete Lawrence.

By now it was coming up towards midnight (goodness only knows what else I'd be up to). Started typing up my observing report and transferring the files onto the laptop for processing.

Dismantled all the kit, had a look around for any bits left on the floor then came in just as a blanket of cloud rolled in from the north west. What good timing!

Hopefully I'll have a stacked image of the SN to show, once I can work out how to process in Deep Sky Stacker. Even if that doesn't work, I'm happy that I've seen it.

 

A  nice few hours outside.

 

James

[dawson]

I don't understand DSS. What it's produced looks even worse than any of my original photos!

Here's the dropbox link for the tiff file if anyone wants to attempt to see if there is a supernova in my data or not:

https://www.dropbox.com/s/vgcamdyfa7dy7x3/M82%20crap.TIF

Jd

[+Ibbo]

Nice detailed report

 

you did better than me as when I got organised it was starting to cloud over.

 

 

Do you PA and then put the scope on the mount? maybe you are knocking it off PA

[+Ibbo]

I'm not sure what you did with the image its certainly vivid

 

 

do you have the output right out of DSS without any processing please?

 

and could you do it with the flats and without

 

just do the darks

Edited January 26, 2014 by Ibbo

[dawson]

Mods - can you move posts #2 and #4 to the start of the new thread in imaging software please? And delete this one?

 

Imaging thread is here: http://www.eastmidlandsstargazers.org.uk/topic/7006-dss-issues-vivid-output-file/

 

Thanks

 

JD

Edited January 26, 2014 by dawson

[dawson]

Ibbo, no, I only ever bother doing the PA once the scope and most of the other junk is loaded on for exactly that reason; especially with the C11 and the mount at full height I invariable clunk against it a bit. What I should have clarified is that I have left the mount outside for the last two months, using it as a semi-permanent setup (the OTA comes indoors). I have been amazed at how well it has kept its PA as I've used it many times in that time and last night was the first time I'd even bothered checking the PA as last time Jupiter wasn't staying on target as well as previously.

 

JD

[+RonC]

Good report James, not sure about that image though, never seen anything like it? Make sure it's RAW ! 

 

Don't forget to edit your signature (can't keep up with all your kit changes!!)

Edited January 26, 2014 by Ron Clarke

[dawson]

Cheers Ron. Signature semi-updated

 

Single shot (60s) jpeg of M82 from last night (I've given up with the stacking idea):

 

 

 

Thanks to Leigh for bringing out as much data as possible for a simple 60 second jpeg - you are the Daddy

 

JD

Edited January 26, 2014 by dawson

[+TasKiNG]

Hi James,

 

I had a play with your tif file in Photoshop and it cleans up quite well.

 

[dawson]

Thanks. That is cleaner than I could get it, but it still looks a mess, haha. I'm trying to re-stack it now using different settings suggested by Leigh.

 

JD
 

[xanthic]

This is what I got out of it. I had to drop a lot from the red channel initially, then tweaked the histogram on the red to make it look more "normal". I altered the white balance to compensate for the filter, then levels and curves to bring out the detail. I think the thing to remember is that stacking is the just the start of the processing. Most images will need a bit of tweaking to get the desire result.

 

 

Edit - Here is before and after.

 

Edited January 26, 2014 by xanthic

[dawson]

Thanks Leigh.

 

I re-processed with the RGB settings as instructed and it made no difference. The colours are aligned but the red is really wide and the core of the galaxy blown out.

 

I'll get some processing tips of you in the flesh sometime, but for now I am happy I could see it visually and have a simple image I can post on Facebook.

 

JD