Question: How do you start trying to look for new planets?

David Robertson answered on 20 Jun 2016:

There are at least 2 ways of looking for new planets.

One is to look for starts that are wobbling backwards and forwards a bit as the orbiting planet pulls on the star. This works best for big planets that are orbiting close to the star as they give a bigger, faster wobble than small or far away planets.

The second way works if the planet gets between us and the star it is orbiting. If it is a big planet then it will block some of the light from the star, so watching a star to see if its light gets dimmer regularly can tell us that there is a planet orbiting it.