Malpi12

Looking on the bright side - now that we have nothing to see the rain-gods will take time off and we will have an exceptional clear sky tonight

The other thing that had me puzzled is that if it had been mistaken ID with the nearby star the magnitude difference was so large how could it have been such a mistake ! So I eeeked !!

Thanks @robin_astro, I wondered if that might be the case ! as the "Type" on the Rochester page was "unconfirmed" but the date was 6th, which was a long time to be still on the page with nothing in their updates page and tks for the def. link

eeek aavso is telling me AT2023mlt "Star AT2023mlt does not exist in VSX" what am I doing wrong I wonder ?

Thanks for the alert @michael.h.f.wilkinson - and Ohh I didnt know DSS could be added, must have another look in the aavso destructions !. I always have trouble aligning aavso charts with stars in stellarium, this should make life a lot easier. I shall have to go portable to catch this one as it is below my treeline all night from my home.

I'm not Michael but I am just setting up my Stellarium for this. it says m9.4 in my version, no moniker though, I'll look in CdC later for it

A brief look out about midnight local (BST) revealed (between drifting clouds) Corona Borealis was missing R Crb ! A hasty grab of the camera on a tripod gave me 5 usable frames, out of 20, to stack and a quick&dirty comparison with some nearby stars in Stellarium gave me :- 297 7.58 HIP77373 257 8.08 HIP77743 234 8.33 HIP78001 184 R Crb 157 9.43 HIP77479 the first column is pixelpeeking in Gimp from the DSS stack so I guessed about mag9 for R Crb

Thanks, yes, I was trying to work out what size of lens my crop image was equivalent to, more here >

Later, after some practice on stacking loadsa subs in DSS and tweaking in Gimp, 1000 subs takes a long time on my ancient windows 7 machine ! I spy spiral arms, (just !!) , but with 5 times as many subs as in previous post, I had expected a better signal 1000 x 2sec, Canon 60D, 135mm f2.8 vintage lens, ISO800, 100 bias, no darks, no flats. Crop of 703x874pixels from original 5292 x 3465 subs and exaggerates the star bloat which I think makes this equivalent to a 1000mm lens ? [ 5292/703 = ~ 7.5, then 135x7.5= ~ 1000mm ]

Yes, ok I was about to update my "discovery" post in beginners imaging forum with it with more details, when I saw your topic. It is a severe crop (and stack) of 703x874 pixels from original subs of 5292 x 3465. If I have my maths right makes it a 135x7.5 = approx 1000mm equivalent lens ?

Yes ! This is a gif of my 1000 x 2sec subs ( Canon 60D 135mm lens, crop, fixed tripod) experiment under yours rotated and horizontal flip.

Thanks to @robin_astro for the alert of SN 2023ixf in M101. Normally sn in galaxies far far away are only of armchair interest for me, being too dim for my current limited equipment. However this one at about mag.11 was worth a try with my Canon 60d +135mm vintage lens on a fixed tripod. 200 x 2sec subs gave me this image below. not pretty but it is there ! The comparison star magnitudes are from an AAVSO chart. Imagine my surprise when I found a bit of M101 as well in there.

North Somerset. Clear of clouds but high haze nelm 4, north horizon limited to 25deg Nothing ! I was out at 00:15 to 00:45 during the first red alert and again at 01:30 to 02:00 during the second red Now it is an amber alert and there is an inviting bottle of amber nectar on the shelf over there, what should I do ?

Thanks, that is what I needed to jump start my brain ! I see now that is where I was going wrong with Webb. I have been happy over the years to accept that the hot glow ( the CHG ! ) from the early universe has, by now, stretched and shifted all the way to a dim 2.7-ishK CMB, -- I have failed to apply the same to "conventional" ancient, early, bright objects like stars, galaxies and Quasars etc., (and anything else that formed at or about 'First Light') which XhaveX will also become stretched and shifted into the darkness of the End Theories -- The clue, I think, was there for me if I had had the eyes to see it: the fact that Webb is working in the IR. (also being able to see through intervening dust) ? edited to change have into will. Cant seem to do strikethro when editing ???

Yes, thanks, got the bit about the space between, I prob. should not have said "cliff edge", Similar - the CMB is not far away- the glow is still all round us but now very cold and weak. I am thinking The Cold Dark End, or The Big Rip was part of this -observable- scenario ? I am off out to a party in a min. so a few bottles may help to clarify