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Very interesting Paul.
By the way, I showed your picture of the volcano going off behind your observatory near the end of the Sky Notes in the October meeting.
I hope things have calmed down.
David
Be assured that this idea is still under consideration and nothing has been finally decided, nor any possibility rejected.
We did subsidise members’ access to commercial remote telescopes in the past, for projects approved by Section Directors. The take-up was very low.
Any insistence on ‘research only’ is also likely to lead to very few people using any facility that is set up.
Variable star, cometary/asteroid and planetary research all have rather different hardware and software requirements.
So the whole thing is not straightforward, and, as has been pointed out, there are plenty of risks and pitfalls. But they could possibly be overcome.
In the next few months I wish to gather together ideas such as this, suggested by members, for ways of spending our funds to benefit observers. Ultimately Council will make a choice, and decide which, if any, projects to pursue.
David (President)
See also my article in the Journal, 2019 December
A better title would be something like ‘Optical aberrations: identifying and treating them’.
The word ‘aberration’ in general means something abnormal. So an ‘Aberrations in amateur astronomy’ would mean anything abnormal in amateur astronomy – like someone claiming to speak Venusian.
David
It’s water in the camera. Common problem in the UK: telltale point is pattern changing as the camera cools.
You need to dry the camera out. Putting it in a warm, dry place for some days might suffice, without having to take it apart.
My preventative solution to this is to keep a dew heater round the nose of the camera and switch it on at least 15 minutes prior to imaging. Sometimes I’ve kept the heater on for days to dry the camera fully.
Thank you all for your replies. There are some useful leads there, which I will be able to distil into a (hopefully) useful reply to the original enquirer.
Thanks Jack, I’ll put it in the next E&T News. But I’ll keep it separate from the cats, as it would poison them.
All the images in this set showed the interesting terminator irregularity in the S hemisphere. It is clearest in the first image, R from 02:38, and I have given an enlargement of that one. Comparing with other published images from the same night, I believe this is due to straight N-S ranges of cloud over the Tharsis Montes casting shadows. The irregularity seen here is a combination of a bright line of cloud catching the light, and its shadow preceding, with another high bank of cloud to S just going over the terminator.
Thanks David, that is very helpful. Is your email still the Freeserve one? I’ll get in touch with further details.
Don’t try contacting the first website that Daryl quotes. People who have been involved with BAA for a while will know why.
The bolts that are supplied with the telescope are about 2″ long, smooth-shanked and threaded with a ¼” Whitworth thread in the top ½”.
They work by the thread engaging with the mirror cell while the unthreaded section passes through the hole in the back of the scope and the knob clamps tight. Owing the varying mirror position at different focus points, I am not sure if they would succeed in in locking the mirror at any point in its focus range, or not.
Assuming they do, and assuming you are using one optical configuration with camera at a fixed distance out in a Crayford or similar focuser, I don’t see why you should not lock the mirror in position with these screws after you have established the approximate focus point for the mirror, with the Crayford in the middle of its range, to give a bit of temperature compensation around that point. However, I have not tried this. I tend to do my critical work around the same part of the sky, the meridian, so the collimation does not change much.
BAA member John Sussenbach in the Netherlands had good conditions, and produced this lovely video. From my location it was too cloudy.
https://youtu.be/8SS-yjY5WakSo it used to work and now it doesn’t, you are saying? There is a clear difference between the images it gave more than 18 months ago and now, even allowing for the decline in sunspots?
All solar equipment does degrade with time, and always needs servicing eventually. If there’s no detail, then one of the filters inside is not performing correctly, and likely needs replacing, which can only be done by Coronado.
I think you are quite right, Peter.
I think when thinkers in all different disciplines are separated from their usual colleagues, usual influences and the peer-pressure that results in people grouped together thinking thinking similarly, original and useful thoughts are very likely to result. Also there is likely to be less distracting day-to-day administrative activity, enabling deeper thought.
I recall the comment of Joseph Haydn, about his period spend at the court of Price Esterhazy in Bohemia, that he was isolated from all the influences he had had in Vienna, and so he was forced to be original, writing his best music there.
I have also been spending a lot of time in the shed at the bottom of my garden, waiting for inspiration to strike.
I’m not sure what Jack thinks is the ‘clear and correct’ answer, as he didn’t say.
This is a matter of social convention, not calculation. No-one was actually counting decades after the beginning of the Common Era (the supposed year of the birth of Christ according to (probably erroneous) mediaeval scholars) in the years immediately after. Therefore there is no continuity here and no reason why we can’t regard the first decade of the Common Era as having only 9 years, or extending from 1BCE to 9AD.
A decade is generally regarded as a grouping of years having the same three initial digits. Therefore the new decade has begun.
An excellent meeting that reminds people the BAA is the premier astronomical society for the whole of the UK.
And I think a special mention is due to the member who travelled furthest to get there: Barry Adcock and his wife made the journey from Australia. He then went to Geneva for the European Planetary Science Congress, where he presented a poster, that he showed me in Armagh, of his work on multispectral IR imaging of Jupiter, done with his amazing home-built 12″ refractor.
Congratulations to Meetings Secretary Hazel Collett, and the others involved in the organisation.
Now we need to solve the mystery of why Armagh Observatory has an orrery that shows 5 moons of Jupiter, but doesn’t show Neptune, which was discovered long before Amalthea.
Thanks for that Bill. I hadn’t seen that Dial-a-Moon site before. It is very useful.
Indeed it shows exactly this effect, produced by the far wall of Bailly catching the light while craters to either side just beyond it, Hausen and Le Gentil, are totally dark. The effect was particularly striking with the field of view on the camera being only about 2.5 Bailly diameters wide. It’s more explicable when seen in the wider view. I also viewed it the other way up (I always invert my images to make them celestial N up for publication), and it seems to look, for psychological reasons, more strange when viewed that way: almost like thew apex of a house roof – see below.
The familiar Moon can certainly throw surprises.
Yes I think it would generally be regarded as best practice to do any data summation (i.e. stacking) before any data chopping, as it is the summation stage that clarifies what is data and what is noise, and therefore doing it the other way round risks throwing away data.
In planetary imaging in twilight or daylight (with filters) we often chop off the sky background level to increase overall contrast, but I do this after sharpening.
But another (odd-sounding) technique which I think does have some legitimacy here is to attempt to guide the way Austostakkert! stacks the images by using as a reference frame an image that has been manipulated, by masking, to be the shape the planet is expected to be. I have seen another other observer get good results on Mercury by this method.
In Berkshire I would have thought the overwhelming effect would be the switching off of lights. I notice this in London: it is much darker after midnight, though none of the surrounding local authorities switch their street lights off.
Yes in theory the airglow, caused by ionised molecules, would have a decay through the night, but, as others have said, it’s not going to contribute much for us.
