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Posted by Marlyn Smith at 23:06 on 2011 Jul 29
Thanks Paul. The Sun does shine in Scotland occasionally, but not often! It’s been quite a few years since we’ve had sunspots like this and I’ve felt compelled to reach for the camera. Long may it continue towards sunspot max in 2013.
Posted by Paul A Brierley at 16:34 on 2011 Jul 29
Hi Marlyn,Know Sun here i’m affraid. I have total obscuration. Very good picture, by the way.
Posted by Marlyn Smith at 15:57 on 2011 Jul 29
Just imaged this using 5" SCT, Type II glass solar filter and Olympus Camedia C-4000 digital camera just held afocally to 20mm eyepiece. Three northern hemisphere’s groups on the disk AR1260, AR1261 and AR1263.20110729 at 1415 UTPosted by Robert Januszewski at 23:45 on 2011 Jul 25
Hi Gary,I agree cities are generally bound by ‘micro-climate’ weather which can differ quite makedly from the surrounding countryside.P.S. I’ll make the spare bed up for you :o)Rob
Posted by Gary Poyner at 13:58 on 2011 Jul 25
Hi Rob,Good to see you on the forum – at last :-)I guess it helps being away from the City. 150 observable nights on average is pretty good for the Midlands, but your a fair distance from a major city. My observable nights can be as low as 69 (2002) or as high as 135 (1995) and that includes gaps in cloud and early mornings. I’ve never had more than 135 observable nights in any one year since I began keeping weather records back in 1978.Just goes to show the difference a few miles makes!Might come to live with you :-)Gary
Posted by Robert Januszewski at 13:28 on 2011 Jul 25
Hi All,In defence of the Meteorologists, precipitation, wind and temp. are usually pretty accurate but cloud cover is more more complex to predict.Having a view that it’s always cloudy in Britain depends on your perspective -like gary I am a variable star observer and not fussed by the moon or even a fair bit of cloud. Over an eight year period I have averged 150 nights per year, and I find that it’s rarely more than two weeks without some clear spells. I have experienced many occasions when it does not clear till after midnight, which for many is too late as work often dictates an early start the next day.Rob
Posted by Paul A Brierley at 20:36 on 2011 Jul 24
Hi Gary,If I had a pound, for every Sunday the skies are clear. I’d be rich by now.Unfortunately. I will have to await the dark Autumn sky’s, before I can do any VSO or general observing, during the week. At the moment any observing is done on Friday’s and Saturday’s.Roll on September.I have a dark sky visit planned on Saturday 30th, with members from Macclesfield AS. Hopefully I can begin to make some observation’s of V Sge, from our observing site on the Derbyshire moorlands. But of course all that depends on the weather.Good luck with any variable observing your doing tonight. Have you seen Comet Garrard yet, through you’re 20"?
Posted by Gary Poyner at 17:09 on 2011 Jul 24
Thanks for the link Paul. The BBC monthly outlook is pretty grim on the surface, but those guys couldn’t predict night time cloud cover if their lives depended on it!The Met Office have a nice desk top widget which can be downloaded…http://www.metoffice.gov.uk/weather/uk/desktopwidget.htmlFirst clear night since Jly 14 here in Brum last night, and chances of another one tonight! Life doesn’t seem that bad after all :-)Gary
Posted by Roy Hughes at 09:31 on 2011 Jul 21
I re-wrote Michael Covington’s software and built a sucesful drive for my old orange tube celestron. Works very well. I’m still using it.My old, now orphan, web page at http://mizat.club24.co.uk/ has details and links to Micheal’s site.I suspect that this will be overkill for this application. It pulls nearly 1 amp at 12 volts. Unless driven from a car’s battery the total result including a battery pack would be far from portable. I took a similar arrangement cobbled together from bits of my home telescopes to an eclipse in Africa in the 70’s and given that it only had to work for a few minutes a 12v stack of D cells worked OK. They didn’t XRay luggage at the airport in those days otherwise I would probably still be in jail today as the resutant stack looked just like the bundle of dynamite sticks that often featured in the cowboy films of my childhood!Roy
Posted by Nick Atkinson at 14:57 on 2011 Jul 20
Michael Covington had a circuit in his book on Astro Photography. I did construct this buying the chip from Dontronics in Australia for Circa £4. This produced a square wave form that was capable of driving a £240 volt syncronous motor. For the dec control you need a reversible DC motor. I modified the circuit with a half bridge driver and constructed a push button controller. You do need to have some experiance in soldering circuits.
Posted by Roy Hughes at 14:34 on 2011 Jul 18
I got curious that Maurice Gavin’s seems to be the only design of clockwork drive available on the net and decided to dig around in old copies of the BAA journal (both digitised and paper!).In 1974, vol 84, no 3 (April) page 189 D. G. Daniels describes a similar device looking a bit more like the one I built (long since gone to the scrapbox in the sky). If you’ve got a fast connection you can download a copy from the BAA (6.57Mb) a real blast from the past. If you do then rather than spend hours trying to scroll to the right issue do a search for time-switch (the "-" IS important!).Roy
Posted by Naimul Islam Opu at 19:41 on 2011 Jul 17
Dear Roy, very interesting suggestion, I am searching for a clockwork motor, already visit several old mechanic shop in my town Dhaka… lets see but i think its not so easy to findout something like that now but I found a Photocopy Machine DC motor with a gear box (made by strong plastic), it is available in nowadays electrics market… just I need to control the motor so i am planning to make a voltage controller circuit to control the motor rpm… its seems to me easy to build an alternative cheep tracking system for anarchic astrophotographer :), i’ll let you know the update, if it is worke then I’ll write an article how to build in our BAA I&I section… thaks for the clockwork idea it helps me to findout the solution. Best wishesOpu
Posted by Gary Poyner at 14:37 on 2011 Jul 16
One good thing about VS observing, is that you can do it in Moonlight! Obviously reduces the limiting magnitude of your scope a bit, and can effect bright red stars if you don’t de-focus, but generally Moonlight doesn’t stop the VS nut from observing. Only cloud can do that! :-)Gary
Posted by Paul A Brierley at 11:50 on 2011 Jul 16
Thank you Gary,I do actually have the BAA Observing guide to Variable Stars. So I think that I will stick with this for the time being.As soon as that Moon leaves the evening sky. I hope to start observing.
Posted by A R Pratt at 11:09 on 2011 Jul 16
Hi David,Thank you for the link. I also came across it a few weeks ago and their buildings look interesting. They don’t have the sliding side panel and end flap of Alexanders Observatories, but otherwise they suit my requirements, e.g. they take bespoke orders.I know people who have Alexanders sheds. It would be good to have a review of a Taylors observatory shed.Best wishes, Alex.
Posted by Gary Poyner at 10:51 on 2011 Jul 16
GOOD books on general VS observing are rare, as they tend to be specialist topics such as CV’s or Pulsating stars. Probably one of the best general books written in recent times is Gerry A. Good’s ‘Observing Variable Stars’ in Patrick Moore’s practical astronomy series, published by Springer. It was written in 2003, but nothing has been published better in this general field since.The field of variable stars is very dynamic, so anything written in a book about a particular type of star in 2003 stands a chance of being out of date in some aspect in 2011, but Good’s book will give you the basics.The Webb Society Deep Sky Handbook Volume 8 written by John Isles is another book I would recommend. Most of it is out of date now, especially the finder charts and some aspects of the analysis section (written over 20 years ago now), but there is a mine of practical information written within the pages which will always be of value. I think you can still get this book from the Webb Society (or maybe the BAA?) and it should only cost a fiver or so (I think).Gary
Posted by David Mottershead at 20:27 on 2011 Jul 15
Hello AlexYou could try this company:http://www.taylorsgardenbuildings.co.uk/observatory_sheds.htmlI haven’t used them myself, so I don’t know what the quality, service etc is like. I simply came across their website while recently researching roll off roof observatories myself.
Posted by Roy Hughes at 16:55 on 2011 Jul 15
Back in the 1960s we all made clockwork equatorial camera mountings out of the elderly (even then) clockwork time switches available on the surplus market.Googling around I found an old page of Maurice Gavin’s version at:home.freeuk.com/m.gavin/tracker.htmI don’t know where you would get the clockwork time switch these days but it might give you some scope for lateral thinking.Roy
Posted by Naimul Islam Opu at 06:39 on 2011 Jul 15
Dear Callum, i’ve tried with ‘barn door’ ‘scotch mount’ or say ‘screw mount’ technique, made it myself some projects but its seems to me sometimes get very good result but not always after several uses occur some errors… i’ve lost many film exposure… first time i was doing astrophotography with film DSLR & ‘screw mount’ is only my tools to do long exposure 🙂 I will try to collect s&t issue as you mentionedMany many thanks for writings Clear Skies! Opu
