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THE ASTRONOMER Electronic Circular No 3110      2015 Sep 26 15.56UT
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, 2015 SEPTEMBER 28
The lunar eclipse will take place Monday morning in UK London
and main times in BST/UT will be:
Begins   01h 11m BST (00h 11m UT)
Maximum  03h 47m BST (02h 47m UT)
End      06h 22m BST (05h 22m UT)
http://www.timeanddate.com/eclipse/in/uk/london

Richard Keen, Instructor Emeritus, University of Colorado, USA, has again
contacted TA to ask for estimates on the Danjon Scale and brightness:
"I am sending this to observers on all seven continents who have observed
lunar eclipses in the past and/or have an interest in these events. As
always, I am interested in hearing of your observations. Some of you may
make "reverse binocular" magnitude estimates, or Danjon "L" estimates, or
both.
Below are some web links with information about the eclipse and about
observing methods, along with links to presentations I have given with
results of this study.  Recent eclipses show that the atmosphere has been
clear of volcanic aerosols since about 1995.  The clear stratosphere lets
more sunlight in, and has contributed about 0.1 degree to the recent
warming, or about half of the total warming since 1980.
Sunday/Monday's eclipse is barely total, with the moon entering the umbra
for just five minutes (from 02:11 to 03:33 Universal Time).  The eclipsed
moon passes deep into the umbra, but misses the centre, which, along with
the absence of volcanic aerosols, means this eclipse will likely be of
"average" brightness.
For those using Reversed Binoculars to observe the eclipse will find several
convenient comparison stars of around magnitudes 2 or 3 in Andromeda, Cetus,
and other nearby constellations.

Article about observing the brightness of the eclipse, including Reverse
Binoculars:
Reversed 7x or 8x binoculars should place the reduced image of the moon
within range of these comparison stars.
Amateur astronomers can measure the brightness of the eclipsed Moon by
comparing it with stars or planets of known magnitude. The Moon, even during
a total lunar eclipse, generally appears much bigger and brighter than the
stars, and its size and brightness need to be reduced before direct
comparisons can be made. An easy way to do this is to view the Moon through
reversed binoculars with one eye, comparing the reduced lunar image with
stars seen directly with the other eye. The estimated magnitude of the
reduced Moon can be adjusted by a factor depending on the magnification of
the binoculars, yielding the actual magnitude of the Moon. For example,
reversed 10x50 binoculars will reduce the apparent diameter of the Moon by a
factor of 10, or its brightness by a factor of 100, or 5 magnitudes. If the
reduced Moon appears like a magnitude 3 star, the actual Moon is 5
magnitudes brighter, or -2. The corrections for 8x, 7x, and 6x binoculars
are 4.5, 4.2, and 3.9 magnitudes, respectively.

Danjon method of estimating eclipse brightness (note that these are best
made with the unaided eye, without binoculars or telescope):
http://www.eclipsewise.com/oh/oh-help/LEdanjon.html

Please send results in the first instance to the TA editor.

Guy M Hurst