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Hi David,
As you say, without more detail on the severity of the visual impairment, it’s impossible to know what might work, but clearly the more light the better…so, a large aperture telescope pointed at the Moon would surely stand the greatest chance of success….Alternatively >Are there any other facilities that a near-blind child might use to get a sense of the planets?< There is this chap, Nic Bonne at Portsmouth Uni, who may (Covid restrictions permitting) be able to offer advice…..
https://www.bbc.co.uk/news/av/uk-england-hampshire-51559823
Martin
Clear overhead last night but quite a bit of haze/low cloud in the direction of the comet. Unfortunately the comet is now just above the orange/yellow glow of Bury St Edmunds some 6 miles away, the worst place it could possibly be. A couple of fixed tripod 50mm f/1.4 shots and a blurry tracked shot with a much slower (f/5.9) Tak FS60c were taken.
Martin
Similar experience to Stewart. Third consecutive night. Observed before midnight UT to take the pics just before moonrise. Comet looked a bit weaker, but may have been poorer transparency, or even the sky glow from Bury St Edmunds (6 miles away) which is not far from the line of sight now…… Same procedure as before. Canon 300D + f/1.4 lens on a fixed tripod. 10 secs single frames and a 12 x 10sec stack… Observed with 10x50s as well. Could not see quite as much tail, possibly for the previously mentioned reasons…..haze, Bury St Eds glow……. Grunting, bellowing animal of the previous night had gone….maybe someone shot it?
Martin
This morning’s pics. Moon less of a problem. Some cloud at first. Another nice view in 10x50s. 10 sec shot with 50mm f/1.4 on a fixed tripod in the farmer’s field. 12 stacked for highly stretched second image. Horrendous grunting/howling noise throughout the session from the direction of the Moon…..Only sheep (as far as I know) in that direction but it sounded like an angry wildebeeste heading my way….. As soon as I had finished I got the hell out of that field ASAP….
Photographed the comet from the field at the back of the house. Fortunately the farmer had mowed it a few days earlier. Used my ancient (2003 vintage) Canon 300D DSLR and bog standard 50mm f/1.4 lens on a fixed tripod. A highly distorted Capella sits in the top right hand corner. (Took some other shots with a 1982 vintage Hanimex 300mm mirror lens although they don’t show any more detail.)They all look a bit pathetic compared to Michael Jager’s extraordinary shots from Austria but at least I have actually seen it now. Nice view in 10x50s. Pity the Moon was up, but at least it wasn’t full!
Martin
Hello Ray,
Apologies. I didn’t spot your post two weeks ago! The link seems to work for me. They sent me a complimentary shirt which arrived today. Quite possibly, re. Patrick….it rings a bell somewhere…. The Melies film was mentioned in the Sky at Night with Michael Bentine – Suns, Spaceships and Bug-Eyed Monsters, on 16th Dec 1977.
Regards,
Martin
I filmed Dave talking about his discovery one year later, at the 1989 TA AGM on 1989 June 24 at Basingstoke. I’ve just uploaded the short clip to youtube. No smartphone videos then… A huge shoulder mounted camera and a heavy VHS recorder slung around my neck! Nick conducted the interview. You’ll find it here:
https://www.youtube.com/watch?v=bxfzpvN3oF0
Seems like yesterday!
Regards,
Martin
Jack,
Yes, the notebook is fascinating. Hay was a highly intelligent man, a perfectionist in comedy and astronomy, and totally different to the bumbling characters he portrayed in films. Unfortunately he became so busy with films in the 1930s that astronomy had to take a back seat and then his health declined just as WWII ended, and just as he was elected to the BAA Council. See: http://articles.adsabs.harvard.edu//full/2009JBAA..119…67M/0000067.000.html
Regards,
Martin
Denis, if you mean the e-bulletins there is an archive here:
http://lists.britastro.org/pipermail/baa-ebulletin/
Mark was back on a few weeks ago repairing a juke box:
https://www.bbc.co.uk/iplayer/episode/m000gppb/the-repair-shop-series-6-episode-2
Martin
Geoff Buss seems like a very good fit Alan. I certainly remember now that he did look like that when he replaced Phil Ringsdore as BAA Lunar Sec Circulars Editor in 1973. I recall talking to him at an Ipswich Lunar Sec meeting around that time. In my mind he looked a bit older than he looks there, but then he would to a 15 year old! I can see the Seiden resemblance too. Can’t recall what Mr Vince looked like. My first thought was maybe Howard was talking to H.Robert Mills…the Stonehenge enthusiast?
Martin
At the 1975 Winchester Weekend the evening skies were clear and there were queues of people waiting to look through telescopes. There was even a short queue for my 60mm Dixons Prinz refractor! The longest queues were for a long 4-inch refractor on an EQ mount, brought along on someone’s roof rack, Henry Hatfield’s 3.5-inch Questar, and the college’s 10-inch AE Newtonian inside a dome. All these instruments were pointed at the same object…Saturn. I attach the ‘Sky Notes’ sheet stapled to my 1975 WW agenda. Also, some time ago a BAA member, Pete Shimmon, sent me (via his brother) 4 pics he had taken at King Alfred’s College during WWs in the 1970s. I recognise Henry Hatfield and Howard Miles but am not sure about anyone else. Two of the pics were taken in the canteen…. All the pics are attached.
Martin
My first Winchester Weekend was 1975. I attach the agenda. Dick Chambers talk on Star Atlases stands out in my memory because the atlases he brought along were, to a 17 year old, highly desirable!
Martin
The ‘might this be you?’ head in a white box is David Graham, former BAA Saturn Section Director.
Regards,
Martin
I think the Dec limitation is far less relevant now but searching deep in the Milky Way is still a big problem. The original Pan-STARRS spec. took 2 to 8 images of the same field each night. The software looked for two rates of motion, 0.75″ to 1.75″/minute (slow) and 3″ to 12.5″/minute (fast). Of course, NEOs are the main target, not comets. The reason for the gap was that software searching for faster than 1.75″/minute produced loads of false suspects, but faster than 3″/minute these could be eliminated because the genuine NEOs would reveal a slight trail in 30 to 60 seconds. Some time ago Pan-STARRS stated their software had now closed the false-alarm gap, ‘away from the Galactic plane’…. So I guess that at an average rate of motion in the gap of 2.4″/minute, objects in the densest part of the Milky Way can still evade detection? There are charts of sky patrol coverage on the MPC website. Unfortunately due to the MPC computer crash of a few months ago these are not up to date, but sky coverage from earlier this year can still be checked…Unfortunately the charts are in RA and Dec only but they do show how dense the Sky Coverage is! The page is at
https://minorplanetcenter.net/iau/SkyCoverage.html
You fill in the details and hit ‘Generate Plot’…..
Martin
I’ve just sent this link to the discoverer, Carl Hergenrother, who occasionally e-mails me…….
I hope he doesn’t die laughing!
Martin
Hello again Dominic,
>My reaction would be to query what the point of publishing these absolute magnitude values is, if the numbers produce such wild predictions.<
I think you might be assuming that the MPC/IAU/CBAT have a team of dedicated comet experts calculating the absolute magnitudes, but they don’t. They are a small group of people who are really, in the case of the MPC, orbit experts, but not light curve experts. When something goes wrong with their computers they take months to fix because they have little spare capacity…this is currently the case with their orbital elements for software packages data….not updated for months!
Really, where magnitude data is concerned, it’s the amateurs who know the most about likely comet performances, based on the developing light curve over recent months and previous apparitions. The guys at the MPC have to put a value for H into the data and presumably it is generated from the initial discovery mag, taking 5 log delta and 10 log r into account, but with little feedback from observers, apart from the magnitude column in astrometric measurements. While the astrometry will only be accepted if it is of a high standard the magnitude data is often very inaccurate. In contrast, the magnitude data found at COBS ( https://cobs.si/ ) is likely to be far more accurate and would be far better for deriving a comet’s likely performance. If the MPC analysed data from, e.g., the BAA’s Comphot software I’m sure their predictions would be far more accurate, but they just don’t have the manpower to keep up to date with all the brightening comets around at any one time. Even if they did, comets are always going to be a law unto themselves as they approach the inner solar system!
Martin
Hello Dominic,
For many years I used to try to do this for the annual Yearbook of Astronomy. It was a bit of a nightmare. The basic problem is that comets are a law unto themselves. Only the magnitudes of the best behaved well-established periodic comets can be predicted with some certainty, and that is rarely as good as +/- 1 mag! My approach with periodic comets was simply to see how they behaved last time round, see what Guide predicted for that apparition, note the error, and then see what Guide said for the next apparition!
The MPC website can give reasonable mag predictions for well-established periodic comets, now and again, but for new comets it is often very inaccurate. Brand new comets may have been discovered in outburst or may brighten rapidly in the weeks after discovery.
As for Blanpain, well, that is a rather extreme example as it was healthy in 1819, then declared ‘dead’, then rose from the dead in 2003 – 2005. So, anyone who can accurately predict its magnitude for the coming apparition would be a genius!
I really wouldn’t worry if your predictions are ‘dodgy’ Dominic as predicting the magnitudes of comets is like nailing multiple jellies to the wall….
Martin
