StarChart
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Whole Sky Star Chart Activity
Current version: 0.27, released 2008/03/04,18:00 UT
This activity will display a map of the sky showing the position of the visible stars and planets, the sun and the moon. You may specify a location (longitude and latitude) and the time (including time zone offset from GMT) that you wish to have a plot for. Alternatively, you can get a plot which is updated once a minute showing the current sky.
Be sure your XO reports the correct time zone offset and the correct local time (the display will default to this)! The astronomical algorithms need to compute GMT (UT) and can't do that if "now" isn't the right time. This is only an issue if you don't use "specify time".
Additional options:
- Select the brightness of the stars being plotted (mag = 0 to mag = 6);
- Select whether or not to draw the IAU constellation figures;
- Choose whether the plot has East on the left (default) or right;
- Choose whether the stars plot as black or bright (default);
- Set "night vision", which makes the bright color red instead of white(default);
- Change the location of the observer for the plot;
- Change the timestamp (and zone offset, if desired) for the plot
This is a beta release. It functions but does not have all the intended features and contains several cosmetic bugs.
NEW FEATURES ADDED IN VERSION 0.27:
A. Latitude and longitude can now be specified as degree-and-fraction as well as degree/minute/seconds.
B. The controls which specify display options, position and time are now organized into tabbed menus like other Sugar Applications.
NEW BUGS INTRODUCED IN THIS VERSION:
11. The "Share" option on the activity toolbar has no function and is presently hidden.
KNOWN BUGS FROM PREVIOUS VERSIONS REMAINING IN THIS ONE:
1. The text color on the toolbar buttons and labels is uncontrolled. (I don't understand PyGtk very well.)
3. The program will not complain (but will also mess up) if you make typos in coordinate or time fields.
5. There is NO support for internationalization. All strings are hard-coded and time values are using US_eng separators (though the timestamp is specified yyyy/mm/dd rather than the natural order).
8. Rotating the screen causes the controls in the toolbars to be truncated/overlapped. (The map displays properly, though.)
9. Due to limitations of the algorithms, the accuracy suffers if you attempt to plot a chart for a timestamp more than +/- 50 years of the year 2000.
10. Even though you have selected "specify" for the time (and therefore the plot will be for the specified time), the update timer runs and causes the plot to be recomputed once per minute. This is a waste of system resources.
BUGS FIXED FROM PREVIOUS VERSION:
2. The default latitude and longitude are hard-coded into the program.
Given that you can now save and restore the position data between sessions, this is no longer a problem. You need simply enter your desired coordinates and then save the session. Next time, resume the session from the Journal to continue using the saved coordinates.
4. The chart defaults to E on the left but the "flip l/r" button is not checked.
I decided this is not a bug -- E on left is "normal" for a star chart.
6. The program icon is very bland.
Not anymore. (Thanks, Aunti Mame!)
7. Display preferences, position, time and offset settings are not saved.
Now they are.
