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I mentioned and illustrated the occultation of Mars on the night of its opposition, December 8, in my Sky Notes at the end of the AGM (which is now on YouTube). This is between 5:00 and 6:00 exactly from London.
I was aware of the occultation of Uranus, but did not mention it as it is not visible from the UK.
I look forward to an in-depth account of the work at the observatory James. It sounds like the capstan needs high friction in the hoizontal direction but low in the vertical, so maybe it should be grooved.
Thanks for your comments Daryl. I’d say if you spend much time looking at the Moon and planets, or double stars, an ED refractor is a very worthwhile upgrade from a standard doublet. The resolution and colour perception are both substantially enhanced by the almost total lack of chromatic fringing. The other advantage is an ED can be made shorter for its aperture and still give good images. The standard 100ED refractor is f/9, but its performance is better probably than a normal 100mm doublet at f/13.
She has been a BAA member, but is lapsed. Still, it’s potentially good that she is interested in the subject.
Seems it’s only possible to post one image per thread in this forum system. Even when I tried to post again with another image it din’t allow it. I’ll have to ask the webmasters about that.
Here’s pictures of the military sighting gadgets I have here. The shorter one is a black-painted brass tube with both a helical focus and a moveable rack-and-pinion adjusted objective, for some reason. Gives an inverted image. No maker name. The other is by REL, Canada, dated 1942. It is a unity power telescope with an extendable objective shield and reticle, gives an erect image, and is a bit lighter than the other one. It looks exactly like a brass bicycle pump.
These gadgets always tend to be too heavy for their optical power to be of any use for astronomy.
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I wonder if there is any link here with A A Common, famous astronomer of Ealing and early member of the BAA. He was involved with the Ottway company and patented devices for sighting naval guns around 1900. Here is a partial listing of patents in his name; they are mostly around this subject. Note the patent numbers are nothing like that quoted, and are much longer. This doesn’t look like a correct patent number.
In the obituary of Common by F W Dyson in MNRAS (1903) it is stated that according to a Captain Percy Scott, RN, ‘The great strides made by the British Navy [in gunnery] lately was entirely due to Dr Common…. He had produced a telescopic gun sight that would, when properly used, quadruple the fighting efficiency of our battle-ships.’
I also have a similar gun sight in my collection. Ottways must have made a great many of them. I got mine from the workshop of telescope maker Irvings (Teddington) when they closed down.
David
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I have a lot of Handbook and Journal back-issues now from the collection of the late Bob Garner of Greenford, Middlesex.
I have plugged the gaps in my collection, so if anyone needs any, do let me know which you are seeking, before I dispose of the rest of them.
David
Yes, what Andy has said is correct.
The programming that is stalled because the programmers are in Ukraine is the overall programming for the system as used by all users, commercial and non-commercial. The idea was that when the basics of the system were working, a few of us would test it, then develop some instructions and make a web tutorial for members. The allocation of time to BAA members was (in part) a transaction in return for our advertising the company, and crediting it in any papers that used results from the telescope. The level of interest would determine whether we needed to devise a system of prioritising certain users. We might have just decided to pay for more time so as to avoid needing to prioritise anyone. If it proved really popular, buying footprint at the facility for a BAA-only telescope on the same system would have been considered as a later stage.
I hope to be able to impart some more news soon.
David
I’m happy to give it away to a member and even pay carriage out of BAA funds. I’m just trying to establish what interest there is in it.
You should get very good results from your setup Tony. Have a look at FireCapture (which is free) for video capture with the ASI764MC. I don’t know how it compares with SharpCap for this purpose, but I use FireCapture. The exposure required is likely to be in the 0.001s range, but in FireCapture you can assess this using the live histogram. You ensure the camera levels are about 75% filled. Gain should be quite high. You capture a video between 30 and 60s length as an SER file, then align in AutoStakkert! using the ‘surface’ alignment function and a grid of alignment points, then select say the best 50% of frames to stack. You can then sharpen the image in another program, or try the sharpening function in Autostakkert!.
One thing I do which I find is beneficial is to use an IR-pass filter on the camera (either in a nosepiece or a filter wheel) in addition to the objective solar filter. (I don’t have the Seymour, I have Thousand Oaks). This steadies the seeing. The result will be a red image. Other people use the Baader solar continuum filter (which is green). Basically you will always improve the seeing by excluding blue light. You can capture the data in FireCapture in mono (no de-Bayering).
Best of luck.
The answer to the question is that we do not publish them on the website. We used to publish them consistently in the Journal, but this has not been done for the past few years.
I think we should (at least going forwards) publish the reasons for all awards both in the Journal and on the website, but I don’t think we should publish the original citations exactly. They are essentially private documents, intended for committee consumption, and not necessarily written with a view to publication.
If we could get round to summarising, and publishing past citations on the website as well, that would be good. If we do, I’ll make sure we start with Denis’s!
David (President)
I am glad the effort (and expense) we went to in order to live-stream the meeting is appreciated.
This feedback makes me more determined that all future London meetings will be streamed. Those held in other locations may or may not be practical to live-stream, and I doubt we would do it with a multi-day event like Winchester.
The Christmas meeting can now be watched on the BAA YouTube channel.
David (President)
The Takahashi Epsilon 160ED retails now at £3,500. If this is not an ED version it is worth less, and being at least 10 years old obviously reduces the value, but they have a very good reputation, so I’d say if the mirrors are in good condition it should be worth at least £1,500.
Thanks for the review. It sounds fair. It is a common observation that the proofreading of Springer’s astronomy books has been poor to non-existent in recent years. Some of them are good, if they have a careful and dillligent author who writes well. It appears this one is not an example of that.
The Board has been in correspondence with the Galloway Forest Dark Sky Observatory with a view to helping them rebuild.
David
