1. p. 1 The Use Of Freeware To Teach Astronomy Dr H F Chau Associate Professor Department of Physics, HKU

2. p. 2 A few freewares are available on the web. In view of time, I shall only introduce one of them: Stellarium

3. p. 3 Stellarium Download from: http://www.stellarium.org http://www.stellarium.org Installation LinuxWindows or Mac Compile the sourceUse the installer

4. p. 4 For Windows version Install to the default directory: –For 32 bits Windows: C:\Program Files\Stellarium –For 64 bits Windows: C:\Program Files (x86)\Stellarium

5. p. 5 In this talk, I shall assume that you are using the 32 bits version of Windows. Current stable version: 0.9.1 Beta version: 0.10.0 Here I will focus on the 0.9.1 stable version.

6. p. 6 Optional Download Userguide –pdf format –From: www.stellarium.orgwww.stellarium.org

7. p. 7 Optional Download Additional stellar data files (Huge files) –To view dimmer stars –From: www.stellarium.orgwww.stellarium.org (Under the banner sourceforge) –Put the files in: C:\Program Files\Stellarium\stars\default

8. p. 8 Starting Stellarium Start via Window’s own start manual Get help by –left clicking the '?' sign –type 'h' For version 0.10.0 Press ’F1’ to get help

9. p. 9 1st thing to do Set –default location –time Save the configuration as default

10. p. 10 You may easily change… Observing location Field of view Direction of viewing Presence/absence of atmosphere and ground Rate of time flow

11. p. 11 You may also track an astronomical object by a few clicks. The –Date –Time –field of view (FOV) –current frame rate (FPS) –properties of the tracked astronomical object are displayed on the screen.

12. p. 12 This program can be used to: 1.Prepare an observing session by previewing the actual event beforehand 2.Aid setting questions by obtaining astronomical data the magnitude angle of parallax distance from the Sun spectral type the right ascension and declination the current altitude and azimuth of a star

13. p. 13 3.Help schoolroom teaching by simulating the apparent motion of the sky In this presentation, I will focus on the third point.

14. p. 14 Writing your own script files Script files must be named.sts Placed either in –C:\Program Files\Stellarium\scripts –Or the user's own Application Data\Stellarium\scripts

15. p. 15 A sample script (from stellarium's example) clear date utc 2006:03:14T21:21:32 select planet Moon pointer off wait duration 2 zoom auto in wait duration 2 timerate rate 500 script action end

16. p. 16 To activate a script 1.Press 'm' 2.Press ' ↑ ' twice 3.press ' → ' twice 4.Select the script file 5.Press 'Enter' 6.Press 'm' to run the script

17. p. 17 Basic operation Stop –press 'Ctrl-C' Pause –press '6' Resume –press 'K'

18. p. 18 I have written a few scripts to simulate the daily motion of stars, the annual motion of the Sun, and the apparent motion of planets. Please enjoy!