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The Use Of FreewareTo Teach Astronomy

Dr H F Chau

Associate Professor

Department of Physics, HKU

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• A few freewares are available on the web.

• In view of time, I shall only introduce one of them:

Stellarium

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Stellarium• Download from:

http://www.stellarium.org

• InstallationLinux Windows or Mac

Compile the source Use the installer

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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

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• 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.

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Optional Download

• Userguide– pdf format

– From: www.stellarium.org

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Optional Download• Additional stellar data files (Huge files)

– To view dimmer stars

– From: www.stellarium.org (Under the banner sourceforge)

– Put the files in:C:\Program Files\Stellarium\stars\default

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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

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1st thing to do

• Set– default location– time

• Save the configuration as default

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You may easily change…

• Observing location

• Field of view

• Direction of viewing

• Presence/absence of atmosphere

and ground

• Rate of time flow

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• 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.

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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

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3. Help schoolroom teaching• by simulating the apparent motion

of the sky

• In this presentation, I will focus on the third point.

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Writing your own script files

• Script files must be named <filename>.sts

• Placed either in– C:\Program Files\Stellarium\scripts

– Or the user's own Application Data\Stellarium\scripts

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A sample script(from stellarium's example)

cleardate utc 2006:03:14T21:21:32select planet Moon pointer offwait duration 2zoom auto inwait duration 2timerate rate 500script action end

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To activate a script1. Press 'm'

2. Press '↑' twice

3. press '→' twice

4. Select the script file

5. Press 'Enter'

6. Press 'm' to run the script

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Basic operation

• Stop– press 'Ctrl-C'

• Pause– press '6'

• Resume– press 'K'

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• 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!