If I need to find any information about stars of universe, the first program which I can think of is Sky mode of Google Earth. I don’t know if this Sky mode is for professional use or not, obviously, I am not into it.

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Here is another application, it’s called Stellarium. It’s Free and Open-sourced, and All major systems are supported natively. You can see many screenshots.

[http://xs138.xs.to/xs138/09143/stellarium-000419.png is gone.]

Google Earth’s Sky mode has many layers and seems to be a little bit of mess if you turn on too many layers. Stellarium is much more clean. Its UI is simple as well and easy to use. However, if you are not familiar with what you just looking at, it’s more easy to access online information with Google Earth.