[BAA-ebulletin 00569] Computing section website - new features - astronomical charts and calculators

[BAA electronic bulletins service]

Several new things have been added to the Computing Section web site:
- We have a new way of generating charts of the paths of planets. It 
shows more stars and in a slightly more realistic way than simply black 
dots (especially if you negate the image in, say, Photoshop). So there 
is a new Charts page under the Handbooks 
tab:http://britastro.org/computing/handbooks_charts.html. This page has 
links to revised charts for Uranus, Neptune and Pluto in 2011. The 
Uranus chart is a correction to the one in the printed Handbook which 
was incomplete. The Pluto chart reveals that the planet is moving near 
to the star cluster M25. Also many charts are given for minor planets. 
Those coming to opposition soon, have charts showing their paths for 1 
month either side of opposition. We think many observers prefer not to 
stay up past midnight so a second group of minor planet charts show some 
which are now past opposition but are more convenient evening objects 
this month and next.
- The applets page (http://britastro.org/computing/applets.html) has a 
new calculator for camera 'field of view' and 'star trail lengths'. This 
is particularly aimed at DSLR users. It can be used to determine what 
focal length of lens (or telescope) would be required to photograph a 
field of a given size. It can also show how short an exposure would be 
needed, for a given focal length, to avoid stars trailing appreciably if 
the camera is fixed. Thus it can help those with minimal equipment to 
get started in astrophotography.
- We have noticed that there is quite a line-up of planets and the Moon 
at the end of May. Diagrams of it have been added to the 2011 Phenomena 
page athttp://britastro.org/computing/data_2010.html. There is a link on 
the left side of the page to "End of May".
If you can write applets, or have ideas for any, then please don't 
hesitate to email me. I don't want the Computing Section to fade into 
oblivion for lack of ideas!

Sheridan Williams
baa [at] clock-tower [dot] com