Three sets of charts for GaN

[Jan Hollan <jhollan@amper....muni.cz>]

Connie and Mark,

a public directory

http://amper.ped.muni.cz/jenik/astro/maps/GaN-Orion/2012/

contains all eps and pdf files now, zipped as well (allall.zip contains 
but the assembled charts for all latitudes, i.e. the all.pdf files). Two 
alternative zenith extinctions are there, 40 cmag and 25 cmag. Of course, 
I'll add some description to the directory later etc., like for 2011.

Crux is below horizon on Jan 18 at 0 degrees, and too low even for -10 and 
-20. People have to wait for larger stellar time to get it high enough. 
Even on Feb 16, Crux cannot be used at latitudes 0 and -10 at 21 local 
mean time. I've deleted such non-usable maps.

At 0 degrees, they can observe at 01 h on January 18, this is the 
stellar time of Apr 15, 21 h, so they have a proper map available for 
using Crux. In the evening, they have to use Orion.

Otherwise I hope the maps are OK. Perhaps some meantime sets could be made 
for Leo, as Mars moves around Regulus.

Gray maps will follow, this takes more time, but I hope to have them 
before Monday.

cheers,
 Jenik

> Connie and Mark,
>
> the above address begins to have some maps now, I'began to work on it 
> today. Orion is ready, in its black on white pdf version. Hope to
> make most of the maps ready today, then the png with black background made 
> on windoze will follow. And then all the zip and tarballs, as for 2011, and 
> a directory renaming from .2012 to 2012.
>
> Fortunately, I've streamlined the map production a year ago, so it should 
> go well now.
>
> Orion is 50 degrees vertically now, to have Sirius on all maps. Having 
> zenith inside some maps, I've added the four main colurs, as was the case 
> with Leo.
>
> What about making maps for ZE = 40 cmag as well -- these might be good for 
> Orion etc. being below 30 degrees? ZE = 25 cmag might be confusing in such 
> situations... I made it for Mar 17, in a subdirectory turbid.
>
> Of course, varying zenith extinction is not the only issue, skyglow from 
> manmade sources may increase quite a lot toward horizon as well, 
> contributing to the stars being less perceptible there. The effect of glow 
> domes over settlements resembles large extinction in its effect on stellar 
> visibility.
>
> best regards,
>
> Jenik