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The latest edition of the Binocular Sky Newsletter is ready. As well as the usual overview of DSOs, variable and double stars, this month we have:
* Uranus and Neptune are back (just!)
* A couple of Mira variables near maximum
* Ceres is still available
* Review of the Bino Bandit
I hope it helps you to get the best out of these short summer nights with your binoculars or small telescopes.
To pick up your free copy, just head over to http://binocularsky.com and click on the Newsletter tab. You can also subscribe (also free) and have it emailed each month.
By Richard Hather
DSO/Doubles - Almach/Albireo/The Pleiades
Date - 21/09/17
Time - 23:00 - 12:00
Lunar Phase - 1% New Moon (not risen)
Seeing - Excellent
Equipment - Skywatcher 12" dobsonian.
Eyepieces/Filters - ES 30/20/14/9
Additional info -
Last night was my first session in a good few weeks and my first light with my ES 30 lovely finder ep and great on andromeda and Pleiades.
Anyway onto the session I had a lovely selection of objects to go at including 2 double stars I’ve never observed double stars before so this was new for me.
I started of with this double star really easy to find and I have to say a beautiful object to observe.
The golden colour of the star to the left was very bright and the blue colour of the star to the right was very striking.
They were a lot closer then I thought they would be and gave me the illusion of moving closer together when I observed for a long period.
I used my ES 14mm which offered 107mag which was well up to the job.
Onto my second double, another easy to find object in the constellation of Cygnus.
I was surprised when I first observed it the gap between both stars is significantly bigger compared to Almach and the yellow star above the blue one didn’t appear as bright to me as Almach.
That’s not to say I didn’t enjoy observing it, the star field alone was lovely to sketch and to get the brightness and exact gap and orientation between both stars was a joy to do.
I decided to use my ES 9mm because of the pleasing view of the object and star field which gave me 167 mag.
Onto my final sketch of the night and honestly one of my favourite objects to observe.
The star field was simple stunning I struggled to fit it all in my ES 30mm which offered 50 mag.
I couldn’t make out and gas around the 7 main stars but the brightness was very intoxicating and I spent a good amount of time trying to get the stars in the right position.
In conclusion a very enjoyable night and a great start to the new season.
Clear skies ✨????
Observing and Measuring Visual Double Stars - Bob Argyle
Good to Fair condition. Please note that this is the original (2004) edition of this book)
Original CDROM of Double Star catalogues missing.
Here is the publisher's blurb on this book.
"Double stars are the rule, rather than the exception: our solar system, having a single sun, is in the minority. Orbiting satellites, ground based observatories and interferometers have all helped discover many hundreds of new pairs - but this has left enormous numbers of wide, faint pairs under-observed or not observed at all. This is where amateur astronomers can help. Bob Argyle, a professional astronomer at Cambridge University, shows where enthusiastic amateur observers can best direct their efforts. The book caters for the use of every level of equipment, from simple commercial telescopes to micrometers and CCD cameras. Amateur astronomers who have gone beyond "sight-seeing" and want to make a genuine scientific contribution will find this a fascinating and rewarding field - and this book provides all the background and practical information that's needed."
I began down the binoviewer (BV) route mainly as a means of achieving comfortable and detailed views of the sun and moon and they have certainly delivered in this respect. I then moved onto planets and have found the detail visible much enhanced using two eyes.
The briefest of peeks at DSOs has not really impressed me if honest but I have never really given it much time. Doubles were also tried and without much success really as there seemed to be a lot of off axis CA and blurring. However, after observing Jupiter the other night in good seeing I turned the scope (a 'champagne' 120ED) onto Epsilon Bootis (Izar) at 156x and the view was initially a bit blurred. I persevered a little and careful centering of the double created a well focused and superbly sharp image with textbook stars.
Realising that the seeing was very good, I put in the 8mm plossls and took the magnification to 292x and the view was the best I have ever had of this double. Stunning sharpness and a 'huge split'. Feeling confident I then turned the scope on Zeta Herculis and this normally challenging object was immediately and very obviously resolved. The view held well and only occasionally fuzzed out.
Moving on to another difficult double, Lambda Cygni, I found the split really quite obvious which was the biggest surprise of all. Doubles like Delta Cygni, Pi Aquilae and naturally Epsilon Lyrae were no match for this set up.
Maybe this is common knowledge to BV users but if you use them and have never tried doubles in good seeing then I'd definitely have a go.