Question about planets discovered outside our solar system.?

Question

I've heard that we have discovered planets outside our solar system because of the shadow they cast when they pass in front of their sun. Can we be missing planets whos orbit does not line up with their sun and our point of reference? Are there other ways to detect these planets?

Answer 1

You're absolutely right: in order to find a planet using this method, its orbit has to line up pretty neatly with the direction we're looking from! It also has to be relatively large and close to its sun, or it won't have a big enough effect on the light coming from its sun for us to detect. There could be tons and tons of planets out there that are too small or too far from their suns or at a bad angle, but we don't have ways to find all of them yet.

I think I recall, however, that if a planet revolves around its sun in a way that we can see its entire year, as if we are viewing the solar system from above, a very large planet close to a small star can have just enough of a gravitational effect on its sun that we can see the sun "wobble" a tiny amount as the planet pulls on it!

We've found some planets that are smaller and further from their suns than we used to be able to find, so methods are improving. You can learn more information from the episodes of the AstronomyCast podcast that cover the topic. I'll put some URLs in the "sources" below.

Answer 2

Most of the planets have been located by their gravity effect on the nearby star. Their presence causes a slight wobble that can be detected with some effort. This is why the planets are either very large (jupiter sized or bigger) and/or in a very close orbit to the star.

Answer 3

Most have a shadow too small to be detected. Instead they are detected by the gravitational effect on the star.

Answer 4

contained in the superb ten years they have got here across nicely over one hundred extrasolar planets, which includes a gas tremendous in easy words 10.5 mild years away. the tremendous Binocular Telescope, an interferometer, should be able to photo a number of them immediately.

Answer 5

There are plenty of ways to detect these planets.

Answer 6

yes