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Hi,
Very interesting, It was just startling bright in the unfiltered ccd image.
I’ll keep an eye out for any meteor captures that have it in frame.
Bill.OK… there were 4 images attached!
Here they are again!Hi,
I was testing out the camera I’ll be using in my next meteor camera system and thought it would be a good idea to check what’s going on with T CrB.
This is a single 5 second unguided exposure, binned 2×2, cropped, linear stretch and re-sized. Taken 2024 04 09 23 46 58 BST. I found a finder chart on line but I’m not 100% sure if T CrB is bright enough to be visible.
I’ve circled what I think might be T CrB. The brightest star is Epsilon CrB for orientation. Does anyone have an image with T CrB in it to compare?
cheers,
Bill.Attachments:
Hi,
I’m not an expert on such things but given our “continuous” montitoring and timestamped images it might be interesting to see how it develops it we get a couple of lucky catches.
Bill.Hi,
Not monitoring purposefully but I like to keep an eye out for anything that might crop up in the background…
A fortuitously placed meteor right next to CrB but no sign of the outburst yet…
Cheers,
Bill.Attachments:
Finally inspiration!
As my old apprentice master would say “…aye, experience, one thing ye canny buy in the shops…” and how true..
Having obtained several more very high resolution spectra of varying kinds it suddenly occurred to me what was going on with this one.
I was also pretty sure that there was an order division but as I was expecting the distinct pattern of atmospheric near IR emissions toward the right of the spectrum, the lines present threw me off track a bit, However your division there was spot on. The issue seems to have been I bumped the focus! When this image is compared to my later ones it is clear this is the case.
Also, one of the other secondary pieces of information that can be gleaned from the spectrum image is that since the 2nd order are so clearly present it indicates that the meteor must have been a slow one. (As well as being rich in Fe lines!) Otherwise these lines would have been overlaid or masked by the pattern of near IR emissions from the atmosphere.
A bit rough and ready but it now all makes sense. Another mystery finally resolved!
Cheers,
Bill.
Hi,
ahhh, I meant “secondary” as in some sort of corrector not a secondary mirror… Even a “perfect” mirror will exhibit some aberrations at f2. Something to stretch it out to f4 maybe, a barlow lens basically, then the camera. I’ve got boxes of lenses to play with that I’ve accumulated over the years. However I have a small fibre fed Littrow spectroscope I built a while back sitting in a drawer. It needs a bit of tlc but offers interesting possibilities. Ultimately the mirror might just become a flux collector rather than a “telescope”, no need to worry about imaging quality then. The next problem is a suitable mount, it is a chunky piece of glass…
It’s all good fun!
Bill.
Hi, Grant/Eric,
thanks for the comments. I’ve used Galvoptics before but they, like Scientific Mirrors are a bit too far south for an easy drive. I’m a regular visitor to Manchester so Orion is not to much further down the M6. I’m always nervous when it comes to shipping big optics. Couriers will promise the earth but “…it fell off the forklift…” has happened to me before!
cheers,
Bill.
Hi,
Thanks all for the various comments. I don’t think I’ll be opting for any fancy coatings as I don’t know how good the mirror actually is nor how I’ll be able to fully exploit such a fast mirror without other aberrations being corrected.
Even if the figure isn’t that good, plain aluminium will do to let me play around with secondary optics with at least usable results.
Might be the worlds shortest dobsonian… ; – ))
I’ll keep you posted!
cheers,
Bill.
Hi Eric,
LOL, Exactly! I had just returned to Uni when it came out. My first copy, which was the hardback version, fell to pieces I used it so much. Currently have a paperback copy and also not for sale ; – ))
Indeed, this one seems to cover the more modern digital side of things but a lot of it seems to be optics and personal profiles which I’m not so into, got far too many books on optics and telescope design!!!
It’s looks like and updated take on the Solar Astronomy Handbook by Beck, Hilbrecht, Reinsch and Volker (Willamann Bell 1995). Also excellent but with the sad demise of Willmann Bell probably only available second hand, although some dealers may have a new copy or two…
I think I’ll give this one a miss at the moment but I think I’ll go and have a wee peek, suitably filtered of course, at the sun this afternoon while the sky is clear(ish)
Cheers,
Bill.
Hi,
Looks interesting… I may be preaching to the converted, as the saying goes, but for me the solar bible will always be Astrophysics of the Sun by Harold Zirin.
First printed in 1988 by CUP, re-printed 1989, it’s a bit dated but it is an excellent science foundation, graduate level but with much for the knowledgeable amateur. Only available second hand now and it seems to be sought after, some of the recent prices I’ve seen are very steep! However If you come across a decent copy at a reasonable price then I’d recommend buying it.
Cheers,
Bill.
Hi,
The devil is in the detail, as they say.
There are definite lines visible longward of the sodium line in the first spectrum plot here and closer inspection reveals quite a few more.
With some stretching there are some 17 “real” lines just above the noise in the original image. I’m still trying to identify these. I’m confident some are W but as for the rest….
There are a few lines in this part of the spectrum in a lot of spectra I’ve captured. I’ve attributed these to weak Fe and Ca but I’ve never captured so many others. The relatively slow velocity of this meteor might be revealing some very interesting features. Work done by Jiri Borovicka on what he calls “the orange band” indicates that some of these line may actually be oxides. This will take more study but this is by far the most interesting spectrum I’ve captured.
Cheers,
Bill.
Hi,
That is a super result. Well done everyone!
I’m glad my guesstimate about the Vg was correct ; – )
One of those “secondary” results that a spectrum can reveal…
Cheers,
Bill.
PS
I had a look at what Ed sent me in 2019. He says he estimated that the meteor was -4, also very similar to the -3 here. Yep, this is an interesting one…
Whilst processing the spectrum I had a funny feeling that this looked familiar somehow….
Couldn’t quite put my finger on it, then I got it!
A while back I was asked to look at, what was then a mystery spectrum, taken by Ed Majden in June 1997 from Canada.
A little cropping to give a better comparison. This is the flare section from the meteor last night.
…and this is Ed’s spectrum from 1997, also cropped on one of the flares…
Remarkably similar morphology!
Hi,
Looking at the radio plots the predicted time of the peak from the graphs looks to be pretty good!
Overall activity seemed to be quite low this year. Didn’t record a single confirmed Lyrid spectrum. However I did record a super spectrum from what is looking like a sporadic (Although this may change, Alex et al have started to analyse the orbit…)
I recorded the meteor on several systems.
This is the zero order image on one of the ZWO cameras:
The spectrum from another ZWO camera:
An instrument corrected plot:
…and finally my usual colourised synthetic spectrum…
The “longest” line in the spectrum image is sodium, very strong, but also very strong emission from Mg and plenty of Fe lines.
Little or no near IR atmospheric lines so probably relatively slow Vg, interestingly, and as as a possible consequence of the low Vg there are no (or very weak) ionised Ca on ionised Mg lines.
Not a Lyrid but lovely!
Cheers,
Bill
Hi,
Thanks Philip, It’s taken 6 years to get a weather break for the QUA’s here too! The HD video cams have produced some exceptional results this year! I’m slowly becoming intimately aware of all little bumps and wrinkles of each shower. The Quadrantids really do have a strong Mg signature, even in the near UV the broad feature is an unresovled Mg triplet.
Whilst reviewing my Narrow Field of View Experiment I noted that most of the QUA’s seemed to have a very uniform light profile, both radially and axially. I’ve put a video on YouTube showing this. https://youtu.be/c8HP1V-5Eik
Cheers,
Bill.
