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THE ASTRONOMER Electronic Circular No 2745      2011 Jun 14 19.05UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074
INTERNET: GUY@TAHQ.DEMON.CO.UK      Backup: gmh@wdcc1.bnsc.rl.ac.uk
WORLD WIDE WEB                         http://www.theastronomer.org
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LUNAR ECLIPSE, 2011 JUNE 15
There will be a total eclipse of the Moon tomorrow night (Wednesday 2011 
June 15) and according to my calculations using Guide v8 software, at 
TAHQ in Basingstoke the Moon will rise in the south east at 20:12UT. You 
will need a very clear south east horizon so perhaps some travelling 
will be involved!

This rising time will vary slightly across the UK and beyond. In 
southern England this means the moon will already have reached 
mid-totality as it rises but we will be fortunate to see the second half 
of the eclipse for about 50 minutes, unlike those in the far north of 
the UK who will not see the event as the moon rises too late for them.

Further details of this eclipse and its visibility for our worldwide 
observers can be seen at:
http://eclipse.gsfc.nasa.gov/OH/OHfigures/OH2011-Fig03.pdf

If you would like to participate in an experiment to see how the colour 
of the Moon is affected by any volcanic dust in the atmosphere, you are 
welcome to estimate its colour from the Danjon Scale described at:

http://sunearth.gsfc.nasa.gov/eclipse/OH/Danjon.html

Please send your 'L number', your location and the time you estimated it 
by e-mail to the main TA Editor.

We also welcome magnitude estimates using the naked eye or reversed 
binoculars.

A late e-mail from Richard Keen, who studies volcanic ash and is based 
USA follows:

Here is some late information about what to expect visually during the 
lunar eclipse in two days. The moon will pass deep into the umbra during 
totality, actually passing over the centre of the umbra at mid-eclipse. 
As such, it should be a fairly dark eclipse.  The visual magnitude could 
be around zero or -1, compared to the -2 or -3 for a more typical 
eclipse. Furthermore, it appears that last week's eruption of the 
Puyehue volcano in Chile may have placed some sulfur dioxide into the 
stratosphere.
Ash from the volcano was reported as high as 13.7 km.

It appears that the ash and sulfur, likely in the lower stratosphere, 
has circled the earth at mid-southern latitudes.
The particles in the southern stratosphere could cause a darkening of 
the southern part of the moon during totality.
However, I am not sure if the particles are high enough or dense enough 
to have much effect.
For those using reversed binoculars, Antares and other bright stars in 
Scorpius should make good comparison stars.  If the eclipse happens to 
be darker due to the volcano, comparisons with Antares could be made 
without binoculars.
Clear skies, happy observing, and keep an eye out for possible volcanic 
effects!

Guy M Hurst