Artist's concept of a rocky planet in orbit around a distant star.
Click on image for full size
NASA, ESA and G. Bacon (STScI)
Planets around other Stars
Did you know that about 200 planets have been found around distant stars? The first planet around a star like our Sun was found in 1995. Since then, a new planet has been found almost every month!
The star and its planet move around each other. The planet moves in a wide orbit. The star just wobbles slightly. This causes a Doppler shift of the light. Most of the distant planets were discovered this way.
Some of the planets pass in front of their star. This blocks out some of the light. It makes the star look dimmer. It's like a solar eclipse. The planet only covers a small part of the star. Only a few of the planets pass in front of their stars.
All of the new planets are too far away to see directly. We can only see their effect on the star that they orbit.
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