Last night Trish was at the helm. All Mike did was take the dust covers off.
M61, a beautiful face-on grand design spiral galaxy between the arms of Virgo, with a type II supernova.
FLI PL16803 camera on 20" PlaneWave on ageing and sticky MI-750 fork mount. Astrodon filters. Luminance 8hrsin 30 min subs. RGB 2 h10m in mostly 15 min subs. Field approx 42 min arc, north up. All scope control robotics, firmware, and image processing software designed and built by us.
The supernova is the brilliant blue star within the confines of the galaxy. It is about 60% of the way toward 2 o'clock edge of the galaxy.
In the raw stack, the SNR is blue-white, as befits something very hot. Mike went to some lengths in processing to preserve the blue: because the strong arcsinh stretch tends to desaturate the brights, leaving a pallid white supernova, we very carefully got the black point and then colour balance right and then resaturated the brights only.
Trish then applied some vigorous and forthright wavelet sharpening to the three main galaxies in the image.
THE FULL FRAME IS HERE where there are other galaxies to be seen, many showing form, as the police would say.
Contrary to expectations, the supernova is not really bang on a spiral arm, but almost in the void between spiral arms. Arrest that supernova! It's breaching lock-down!
Edit: We previously used the 15 minute colour data as additional luminance. We've since shot completely fresh luminance data, dropped a couple subs taken with the galaxy low in the sky, and we're up to 8 hours total luminance. The image is a bit sharper and deeper.
Cheers from the farm (where current livestock consists only of Colonel Mustard the rooster, and the three Spice Girls, Ginger, Pepper, and Anise)
Well, lookie that nice blue star , a great record of this event, always feels that bit more special when you use your gear for something interesting and new like this
The MI mount is ageing and sticking huh..?...any plans on an upgrade?
Did the poultry understand when you explained the image to them? or were they too chicken
Well, lookie that nice blue star , a great record of this event, always feels that bit more special when you use your gear for something interesting and new like this
The MI mount is ageing and sticking huh..?...any plans on an upgrade?
Did the poultry understand when you explained the image to them? or were they too chicken
Mike
Thanks Mike. Sadly the chooks are only interested in handouts of grain and grubs. Even more sadly, we've invested so much in all the control software that we're prepared to put up with losing one sub in five to sticky bearings. But they are very tight. If ever we were to start again, which I doubt, I think I'd go for something with direct drive and encoders on the axles. Perhaps when they bring out one of those avalanche diode cameras with zero read noise for an affordable price. Or perhaps we'd just rent time on something in Peru with 0.5 sec arc seeing, learn to tango, I would grow a bandito moustache, and we'd sip tequila.
Quote:
Originally Posted by Ryderscope
A stunning image and SNR record that befits the additional work and expertise applied to maintain technical
accuracy and aesthetics throughout
Thanks muchly Rodney. That's our third discovered-by-someone-else photographed-by-us supernova, I think. A very bright one in NGC 1365, one in NGC 1532 colliding galaxies, and this one.
Quote:
Originally Posted by Andy01
Interesting target with a great backstory.
Doesn't look very sharp on my monitor though?
Good to see a new one too!
You had us puzzled for a while. SmugMug keep changing their interface. We accidentally posted a link to a smaller than full size version. We've updated the link to point to the original.
Quote:
Originally Posted by Peter Ward
What a superb rendition....an island universe...with extras!
Well done
Thanks Peter, that's encouraging.
As mentioned before, the original link was to a reduced-size version which wasn't so flattering. The link is now correct. D'Oh.
Last edited by Placidus; 16-05-2020 at 03:54 PM.
Reason: Wrong link
Wow great galaxy/supernova capture there Trish n Mike!
The colour is particularly good & the full frame with all the surrounding galaxies gives great context.
As mentioned earlier, we inadvertently posted a reduced-to-half-size version courtesy of SmugMug no longer letting the author explicitly choose Original Size. Seems the owner has to that click twice on the image to get full size, and then save the link. The link is now correct if anyone wants to have another peek.
Quote:
Originally Posted by Retrograde
Wow great galaxy/supernova capture there Trish n Mike!
The colour is particularly good & the full frame with all the surrounding galaxies gives great context.
Thanks Pete. I counted 53 certain and another 10 probable background galaxies. Not our Personal Best, which was 144, but ok for 6.5 hours under a gibbous moon.
Quote:
Originally Posted by multiweb
Top stuff Mike.
Thanks muchly Marc. At the risk of seeming to be milking the penalty, have another peek now that I've posted the Real Thing.
Spurred by Andy's comment that he thought it looked a bit blurry, we've chucked some frames taken with the galaxy low in the sky, shot an additional night's worth of luminance with no moon, and used dedicated luminance only (i.e. not using RGB as additional luminance).
We think it was pretty good to start with, and actually thought Andy was pulling our leg, but it is unquestionably a tiny bit deeper and sharper now.
TThe biggest change is the colour which might be a bit more natural now, with subs taken under moonlight scrapped.
We think that more data has also meant very slightly less artifact.
Lovely work M&T! And it's a great record of the SN too!
Thanks Marcus. Ephemeral things like meteor showers occultations and eclipses don't normally grab us, but supernovas seem very special. Without them, we wouldn't be here.
Quote:
Originally Posted by cometcatcher
Awesome work MnT! Interesting how wide that rig can go. Lots of other galaxies in the field too.
Thanks Kevin. The galaxies far, far away can be as much fun as the main subject.
Even more sadly, we've invested so much in all the control software that we're prepared to put up with losing one sub in five to sticky bearings. But they are very tight.
That really sucks, nothing worse than a misbehaving mount. Any possibility of repair?
That really sucks, nothing worse than a misbehaving mount. Any possibility of repair?
Thanks Lee. I could replace the entire polar axis sub-assembly, but there's 150 kgs of other stuff that would have to be painstakingly disassembled and winched off bit by bit.
Nicely smoothed out. I imagine the Milky Way galaxy would look a lot like this from a distance. Perhaps a bit more of a bar in the centre but the arms look remarkably similar to the Milky Way.
Nicely smoothed out. I imagine the Milky Way galaxy would look a lot like this from a distance. Perhaps a bit more of a bar in the centre but the arms look remarkably similar to the Milky Way.
Greg.
Thanks Greg! Hoping that's not code for "too smoothed out". I try to use judicious wavelet smoothing, just to the point where the grit in the blacks is gone, but there is no detectable effect on the actual data. Perhaps if people can't see the background grit, they think that the image is blurry. But the closest faintest doubles that were resolved before are still resolved, for example. Tell us if we're overdoing it.
, a great record of this event, always feels that bit more special when you use your gear for something interesting and new like this 
