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BAA electronic bulletin No. 00506 http://www.britastro.org/
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VENUS: the 2010 E. Elongation
At the present time, as in 2002, 1994, 1986 and 1978 (etc.), Venus is
favourably placed for observing its gibbous disk with phase around 0.60.
Although the planet is only a few degrees away from greatest elongation,
its declination is just north of the celestial equator (as of 2010 late
July), and quickly decreasing, so that many observers will find the
planet too low to see above the treeline in the evening sky and daylight
observation may be called for. Finding the planet with setting circles,
the Director recently had several good views around mid-afternoon. If
possible, shield the telescope tube from the direct rays of the Sun as
otherwise tube currents will spoil the seeing conditions.
We have a fair number of observers making and contributing all-important
ultraviolet images, but (ironically) very few visual observers. It is
important to continue to monitor the clouds of Venus for any unusual
phenomena, so adding to the historical record. The recent bright spot is
a case in point: see the 2009 October BAA Journal (119 (5), 240 (2009)).
Therefore please try to make drawings of the planet in white light and
if possible through the appropriate Wratten colour filters (see the
Observing Guide for more details). We require careful sketches to show
the apparent phase, a note of the relative size and brightness of the
cusps, and positions of bright and dark markings. Timing the moment of
apparent half-phase (dichotomy) is important for the purpose of
historical comparison: at evening elongation this normally occurs around
5 days early. A large number of such observations made in early to
mid-August will be essential for this programme. Phase
work is best done visually, because images appropriately exposed for
the majority of the illuminated disk will underexpose the terminator.
>From phase approx. 0.30 or lower, please examine the planet against
the darkening sky to search for extensions of the cusps or the elusive
Ashen Light. In 2010 such studies will only be possible from the
southern hemisphere due to the planet's high southerly declination
towards inferior conjunction.
Report forms can be obtained by post from the Director or downloaded
from the Section's website. The webiste has recently been updated by
David Arditti and is currently a 'work in progress'.
Richard McKim, Director
======================================================================
BAA electronic bulletins service. E-mail: circadmin@britastro.org
Bulletin transmitted on Mon Aug 2 23:34:13 BST 2010
(c) 2010 British Astronomical Association http://www.britastro.org/
======================================================================
-- BAA electronic bulletin No. 00506 http://www.britastro.org/
======================================================================
VENUS: the 2010 E. Elongation
At the present time, as in 2002, 1994, 1986 and 1978 (etc.), Venus is
favourably placed for observing its gibbous disk with phase around 0.60.
Although the planet is only a few degrees away from greatest elongation,
its declination is just north of the celestial equator (as of 2010 late
July), and quickly decreasing, so that many observers will find the
planet too low to see above the treeline in the evening sky and daylight
observation may be called for. Finding the planet with setting circles,
the Director recently had several good views around mid-afternoon. If
possible, shield the telescope tube from the direct rays of the Sun as
otherwise tube currents will spoil the seeing conditions.
We have a fair number of observers making and contributing all-important
ultraviolet images, but (ironically) very few visual observers. It is
important to continue to monitor the clouds of Venus for any unusual
phenomena, so adding to the historical record. The recent bright spot is
a case in point: see the 2009 October BAA Journal (119 (5), 240 (2009)).
Therefore please try to make drawings of the planet in white light and
if possible through the appropriate Wratten colour filters (see the
Observing Guide for more details). We require careful sketches to show
the apparent phase, a note of the relative size and brightness of the
cusps, and positions of bright and dark markings. Timing the moment of
apparent half-phase (dichotomy) is important for the purpose of
historical comparison: at evening elongation this normally occurs around
5 days early. A large number of such observations made in early to
mid-August will be essential for this programme. Phase
work is best done visually, because images appropriately exposed for
the majority of the illuminated disk will underexpose the terminator.
>From phase approx. 0.30 or lower, please examine the planet against
the darkening sky to search for extensions of the cusps or the elusive
Ashen Light. In 2010 such studies will only be possible from the
southern hemisphere due to the planet's high southerly declination
towards inferior conjunction.
Report forms can be obtained by post from the Director or downloaded
from the Section's website. The webiste has recently been updated by
David Arditti and is currently a 'work in progress'.
Richard McKim, Director
======================================================================
BAA electronic bulletins service. E-mail: circadmin@britastro.org
Bulletin transmitted on Mon Aug 2 23:34:13 BST 2010
(c) 2010 British Astronomical Association http://www.britastro.org/
======================================================================
Good Clear Skies
--
Astrocomet
--
Colin James Watling
--
Profile: http://www.google.com/profiles/astrocomera
--
Real Astronomer and head of the Comet section for LYRA (Lowestoft and Great Yarmouth Regional Astronomers) also head of K.A.G (Kessingland Astronomy Group) and Navigator (Astrogator) of the Stars (Fieldwork)
--
Web: http://lyra.freewebsites.com/
--
Information: http://www.clubbz.com/club/2895/LOWESTOFT---3054/Lowestoft%20And%20Great%20Yarmouth%20Regional%20Astronomers%20(Lyra
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