Forum Replies Created
-
Posts
-
I must apologise that I gave a ‘smarty response’ but I really like ‘In praise of dogs’ and have it posted on my study wall with the item ‘When a dog gets old…’ underlined in red. My wife of 57 years is not amused….. Life is for living dangerously!
My own weather woes this year are very similar with considerable cloud and often light rain. As a southern hemisphere lunar occultation observer with the approaching lunar standstill I have the additional problem in recent months, when the crescent to first quarter waxing Moon is too far north among the trees to access from my observatory and so last month I used my 63 year old 24cm reflector – a simple instrument on a wheeled base. (see image from its 1968 update) This period from crescent to first quarter is generally very productive but though I have cleared a swathe, trees can occasionally be frustrating when the Moon is at extreme (particularly north) declinations. See images.
Thought I live in the hills within 10 radial kilometres of the centre of a city (Brisbane) with a 2 million metropolitan area population, my night time zenithal sky has only deteriorated from around mv 5.5 to 5.6 to 5.2 to 5.3 in the fifty years we have lived here. I made the decision when we bought and built that I needed quick access to the city, principally for work, but for other amenities as well, so compromised on the dark sky since my main interest was solar system objects. Deep sky enthusiasts have either settled or have sites 100 kilometres or considerably more from the city/Gold Coast areas.
My main complaint at the moment is about the continuing wet weather and the southern face of the observatory end posts and roof (not in sunlight at this time of year) are exhibiting a yellow tinge that I will clean off when the weather clears.
Let us all hope that clear skies soon return.
Hello Giovanni,
Regarding your item 2 above, I would stick with your dogs. – See attachment
Regards,
Peter
Attachments:
Weather here in Brisbane Australia has been fairly cloudy for much of 2023 and more so this year. My lunar occultation results reflect this. I forwarded the wonderful image of the weather forecasting stone to a friend who came back with a picture taken on 6th April this year of a similar stone in a park in Tenterfield, New South Wales (Australia). A couple of small differences – jumping = earthquake and gone = cyclone – after all we are in the southern hemisphere -and cyclone is the equivalent of hurricane, tornados being relatively unknown. Are these stones multiplying?
Peter A.Attachments:
Paper envelope: Well, you can’t please all the people all the time.
My February JBAA arrived yesterday and was jammed partly sticking out of the letterbox. We too have have reduced mail deliveries alternating between 2 and 3 days a week as ordinary ‘snail mail’ proceeds in its death spiral – costs of mail increases and services reduce. It is hard to know which days of the week the mail will be delivered. Anyway our letterbox is 160 metres from the house and it had rained overnight. I checked this morning. The result is that I am currently drying out my BAAJ and the pages do tend to stick together. The plastic cover would have shrugged off the small amount of rain we had…..I am following the debate with interest and I can see both sides. (I joined in 1969 and so am now four years into my honorary membership.) As an honorary member and being overseas I gladly contribute 21 pounds per annum to continue to have a paper copies of publications mailed to me – but these mailings are out of pocket expenses for the BAA and do not contribute to the general running expenses.
Many years ago members could purchase a life membership by an upfront payment but this was discontinued because it became simply a wager as to how long you would last.
My feelings on attaining my 50 years standing was one of achievement, rather like my 65 years involvement with local clubs, my near 50 years observing and timing lunar occultations, and when I finally built it, my 44 year old observatory. I am still active and contribute to two sections of the BAA, one of them intermittently since the late 60’s/early 70’s. Now age 81, I certainly agree that with some luck and good management, retired people have the money to easily afford the membership fee and much more, but that is not the point. It is simply the recognition. Even your motoring clubs like RAC (here anyway) give out gold memberships after 50 years. (You just have to live long enough!)
To sum up, I feel it would be reasonable to honour this class of 50 year plus members, and even reward their loyalty by a reduction in membership fee – I think half fee was suggested, and this should cover the obvious administration expenses – and I am happy to also pay any extra postage as I presently do. Clearly we must cut our cloth to fit the current circumstances and I believe that with the internet, the residual effects of the Covid pandemic, and the the ready availability of you tube and zoom meetings, we have largely lost the comradarie that we once had when we could only reasonably pursue our interests by joining a club, attending meetings to listen and make friends, and borrow books from their library.
Our local club, much like the BAA is shrinking and only half the size it was in the early space age, composed of an ageing membership (very few under 50 years old), with key individuals engaged in their own narrow fields of interest as I am. Having some mobility problems myself I have attended meetings by zoom only in recent years.
I can’t see that it will be getting any better. Same goes for the club instruments available for loan – no-one seems interested any more. Instant gratification by the internet is so quick and easy.
Even my wife of 56 years is not helping. When in a moment of candour (maybe being a bit pompous), I said to her that I would like to leave something behind in the field – she said ‘You mean like a cow?’ I was puzzled until she added “Well it leaves something behind in the field too.’
So I think we should rely on BAA council to come up with a solution to honour our long standing members but not have the shifting demographics place an unfair burden on the rest of the association. As for obtaining new and younger members might I suggest an earlier British tradition called ‘Press Ganging’?Regarding the previous post, I am sorry for the error but results on the charts below mv5.0 (not mv4.0) appear in red.
The light pollution map is a worldwide one but we each have our own parochial area that we worry about. Mine is Brisbane Australia where I live. The population is now 2 million.
In 1978 when I arranged the first light pollution survey I decided to plan it carefully. The idea was to conduct the research over a short period of time in the mid evening between a short range of dates in the dark of the Moon and distribute charts of Scorpius marked with stellar magnitudes. Scorpius, easily recognisable, was near overhead at the time in July and so the problem of a bright horizon in one direction or the other was avoided. Also the zenith was ‘as good as it gets.’ Instructions about dark adaption were provided.
This exercise was conducted by the Astronomical Association of Queensland in 1978 and repeated in 2018. Though the number of participants is limited, the deterioration in the intervening years is obvious.
A few points about the attached image. Results below mv 4.0 are shown in red. There were only a few participants who contributed to both surveys, myself being one of them, where my results deteriorated from mv5.8 to mv5.4. Observations from near the centre of the city achieved mv4.8 in 1978, but only mv3,2 forty years later. Now of course, though I have tried to approach this scientifically, the big variable in such surveys remains the variability (acuity) of the eyesight of individual observers, plus the tendency to ‘talk up’ your own pet observing site.
Attachments:
Thanks Darryl and David,
Wal Best’s Observatory at Bardon, Brisbane: I supply some background. Wal Best was a retired gentleman who built his observatory in the early to mid 1970’s. His property was quite vegetated and his wife wasn’t too keen on cutting a number of trees down, so he elected to use an old water tank on his property that in past times had been used to supply gravity fed water to the house. He had recently retired so it was a suitable work intensive project. So he trimmed off the tank at around 4″ in height from the base and filled it with concrete upon which he lovingly built a single skin circular brick wall and crafted a very fine aluminium dome with marine plywood frame. The quality of the work was outstanding. The dome was about 10ft diameter and a 12.5″ Dall Kirkham Cassegrain was installed within. He used this for perhaps two decades.When Patrick Moore arrived for the 1988 ‘Brisbane Expo’, he was keen to climb up, but was prevented by a wartime injury. (He was in the RAF and said he had fallen out of a bomber onto the tarmac during the war and the knee injury continued to be troublesome.) I know all this because I took the photo. The other person is Susan Niven, a local club stalwart.
150mm F8 Achromat compared with ED glass version: This is a typical example of me being too stingy. (‘Tight-arsed’ as my wife puts it.) I saw the Celestron 150mm F8 optic tube half price for $600 AUD and I always wanted a big refractor so I bought it and mounted it in a cheap superseded heavy duty DX mount. Less than 18 months later the Skywatcher 150mm F8 ED was reduced from $3,000 to $2,000 as a special and so I swapped over selling the Celestron for a loss. In the meantime I had done quite a bit of testing and it was easy to conduct the same tests again for a direct comparison with the same mount, and same camera etc.
I support David’s statement about the performance comparison, but I do feel that the standard achromat does have its points. Call me perverse, and maybe it was the spurious colour it introduced, but I felt that the standard achromat produced a bit more contrast on (say) the planets. From the lunar images – base of page 25 in the E&T News you will see that the spurious colour effects become troublesome towards the outer areas of the field. I have a series of these comparison lunar images if anyone is interested.Thanks Xilman, This is another aspect and there is valuable information there, an aspect I had not directly considered. On the basis of this it would appear that it would be safe (if dazzling) to look at the Sun from the distance of the Orbit of Neptune. (30AU). But are there other factors in play?
Hello Bill, Whilst your mathematics are good, the problem as I see it is that the visible disk will remain the same brightness and so has the potential for the same sort of damage if you look at the sun. However, and obviously the heat factor transmitted within the eye will be much reduced if the solar disc has a reduced angular size. Taking my argument ad absurdium, you could reason it is dangerous to even look at the stars, but in those cases their stellar disc is not resolvable and instead you are examining a disc produced by your eye or telescope optics that is many times the actual stellar disc diameter and so a mere tiny fraction of its true surface brightness.
I think we need an expert to provide some considered and professional advice on the subject. I feel like an ancient Greek trying to form a hypothesis just by reasoning alone.
Hello Stan… Thanks for your further advice. If indeed the front gardens are pebble coated for cars, clearly the garden and the ‘rock’ in question have been cleared away. The only hope might be that the rock was kept or referenced to some authority because it was unusual, and so there may be a trail or someone might remember. (Not very likely now after 59 years!)
On the subject of staying in the one property, one of the reasons we searched for our present property is that I could build an observatory in the backyard with clear east and west horizons for my lunar/planetary observations – and still be close to the city for my work. Quite a ridgetop site. See photo. The house is behind trees to the right from this angle.
Yes, I remember the international events from this time well. I was only 19 but followed the news closely.
I know that 60 years have now passed since this event but wonder whether you, Stan, might be able to pinpoint the house and garden in question where the ‘fall’ occurred. Perhaps the current occupants might know something. Maybe the ‘rock’ is still there.
I know that people move around, buildings get demolished and rebuilt and all sorts of changes occur. But some things also stay the same. For example When I married in 1967 we had a house built but moved to our present (new) house in 1974 and have stayed here ever since. So if something had fallen here since then, we would have a very good chance of finding it… subject to some gardening etc. Our original house also remains effectively the same.
So, I know it is easy to remove a quarter brick sized rock, but maybe it wasn’t moved… I am suggesting that maybe a few enquiries might turn up something and suggest an inspection of the site…. A few further enquiries might be able to put it to rest one way or another. At the moment it is a tantalising question mark- what happened to the steaming dull black rock?
I have made the adjustments. I am also placing it on my member’s site (in more detail.) I have versions with and without text.
I would be happy to make adjustments if my images were to be selected, but there will doubtless be other worthy contenders.
I thought I should answer the call with four images to show the progress of the occultation of Saturn on 12th August 2019. (taken with a C14.) I have literally dozens in the series, but the more that are included, the smaller each becomes, and if we resort to cropping, then the effect is lost. I am not particularly hopeful, but if the images look interesting, I can supply futher details
My C14 (in 2014) came with these bolts to secure the mirror. They were screwed through the back of the tube to secure the mirror fixed in place and needed to be removed or at least loosened so the telescope could be operated. There were strict instructions that they should not be used to lock the mirror during observations. Celestron said it was okay to remove them completely. (Unless the telescope was to be shifted – which was what they were designed for, they were not to be used.) So I removed them completely and stored them appropriately labelled. I covered the holes with adhesive rubber pads. I don’t know whether this has helped… Maybe they can be safely used by a responsible adult… Where to get them? Perhaps from Celestron or a dealer. You can see the ‘mirror lock screws’ in the attached image.
I seem to have very little image shift anyway, but my work is not critical.
A few images, partial viewing, the eclipse, and afterwards
