Supernova in Ursa Major (SN2011by)

[MikeWilson]

Hello all,

Since seeing was pretty poor this evening (humidity reflecting light pollution) such that The Plough was only just visible to the naked eye, I thought this would be a great time to test out a new CLS filter, and the Brightstar filter wheel.

What I needed was something faint. Very faint. Magnitude 12 or lower...

So here I present the first 5 x 5 minute subs of SN2011by on the QHY8L with CLS filter during poor seeing.

The camera is still chucking out subs, I think I'll stop on this target shortly.

I noticed quite a lot of dust bunnies on my flats which is evidence that I haven't quite got the hang of it yet. Fortunately I have one of those swanky Aurora EL panels on the way which should hopefully solve my flat taking issues and make the workflow a little more consistent.

Mike

[AndyUK]

Looks like a very good test to me, Mike...! The seeing was slightly better in the SW, but I reckon there may have been some high wispy clouds up there at the start of the night. You'll have to let us all know how you get on with the EL screen (I've been looking at those too!)

[cgarry]

Good work Mike. I have a quick capture of this target a few weeks back and will capture it again later to see the changes in the supernova.

How do you find the QHY8L compares to the 550D? I am really tempted by the QHY8L but am worried that it is not a big enough step up from my 450D.

Cheers,

Chris

[MartinB]

Well you've got it there clear enough esp the second image.

[fatwoul]

I think I would struggle to find with with my Titan.

[Tom How]

Now buy yourself a Star Analyser grating and make a spectrum of it so you can prove it is a supernova!

[MikeWilson]

Hi chaps,

Thanks!

RE: Star analysing, it looks very intriguing - I'm tempted. But how does one determine the spectrum of the star in question, do you get spectra diffracting out from each of the stars? What happens when you have more than one star in a field, each contributing to the overall recorded spectra?

RE: Titan - I think you can capture it!

RE: 550D.. The QHY8L is a significant upgrade from a modded DSLR.. The cooling means a huge reduction in noise and the extra sensitivity means you capture more photons over the same amount of time. It's not a mono CCD, but it's certainly a worthwhile alternative and a good upgrade from a DSLR.

[MikeWilson]

RE: EL screen - I've got one and first impressions... Instructions in German - "LOLWUT?" (as today's internet generation would say).

Fortunately the included English translation (note the transformer only comes in German) makes a reasonable amount of sense. It's a very study piece of kit and not square like in the FLO photos, but round like a dinnerplate. It has an opaque reverse and isn't as bright as I thought it would (should?) be.

But it seems to take perfect flats just as advertised. I've taken pictures and I'll share them in the equipment discussion section shortly.

All the best,

Mike

[Tom How]

you use a grating to create a spectrum which is captured on the camera and measured in post processing. You get a spectrum from each star, but they are not very long and a bit of rotating of the equipment normally gives you a clean spectrum

A very old page of mine actually before I had a SA

Astronomy Spectroscopy with modified Webcams

very useful Yahoo group

staranalyser : staranalyser

[cgarry]

RE: 550D.. The QHY8L is a significant upgrade from a modded DSLR.. The cooling means a huge reduction in noise and the extra sensitivity means you capture more photons over the same amount of time. It's not a mono CCD, but it's certainly a worthwhile alternative and a good upgrade from a DSLR.

Thanks Mike. I have been looking at getting one of these for a little while and your adventures with one have helped me decide that I will.

I like to capture some images but I am not serious enough about it to bother with the work flow involved with a mono CCD. So the QHY8L seems ideal to me.

Cheers,

Chris

[MikeWilson]

I've added more data to this and reprocessed.

A Supernova in a distant galaxy (SN2011by in NGC 3972) by MikeWPhotos, on Flickr

A Supernova in a distant galaxy (SN2011by in NGC 3972) [negative] by MikeWPhotos, on Flickr

These were taken before the Gerd Neumann Aurora panel and Bahtinov masks were added to my kit collection I'll post reviews on both later.

I'm very happy with the QHY8L, Chris. It's a good cooled OSC.

[AndyUK]

A nice reprocess, Mike - It looks as though the B mask has certainly had an impact as those stars look a bit tighter... (or is that just my tired eyes?)

[MikeWilson]

A nice reprocess, Mike - It looks as though the B mask has certainly had an impact as those stars look a bit tighter... (or is that just my tired eyes?)

Must be your eyes, since I didn't use the focusing mask (I didn't have it) for these subs :-)

I did however remove a few subs that had any sign of star trailing. In DSS instead of registering and stacking in one click, I've split the process into registering, then checking the 'score' and number of stars and then stacking after evaluating the lowest scoring frames.

So that's why this time around looks better

All the best,

Mike

[AndyUK]

Ah... yes... If my tired eyes had read your post properly, they would have noticed that you'd actually already said that - Sorry (I need a holiday... or more likely some sleep!)