There are two tools that astronomers use to determine that a far-off star has planets.
1. Occultation: When a planet passes in between the Earth and another star, it is called an "occultation", from the Latin word "occult" or "hidden". The light measurement from the star will be slightly decreased when a planet passes in front of the star. Think of it as a very par away eclipse. This only works for very large planets.
2. Gravitational "wobble": A large planet attracts a star as much as the star attracts the planet, and they both orbit their joint center of gravity. Because the star is so much more massive than the planet, the star only wobbles very slightly, but over long periods it is possible to notice the differences.
No. Other stars have been found to have planets orbiting them.
That depends on which solar system and planet you are asking about - we now know for planets orbiting other stars.
We expect the Andromeda galaxy to be just like our own Milky Way galaxy. We can see stars (suns) in the Andromeda Galaxy and just as stars have planets orbiting them in our galaxy, we believe that there must be planets also orbiting stars in the Andromeda galaxy.
Yes. To date scientists have discovered well over a thousand planets orbiting other stars. It is believe that a large portion of the stars in the night sky have planets.
* Moon - A body orbiting a planet * Planet - A body orbiting a star * Star - A ball of burning gas * Solar System - A collection of planets and satellites orbiting a star or stars * Galaxy - A collection of stars * Universe - The area which contains every particle of matter in existence
Orbiting stars. We know of eight planets orbiting our Sun, and we know of over 300 planets orbiting other stars.
You will see stars/planets orbiting what looks like nothing.
There may be planets orbiting stars in the constellation Gemini, but planets do not orbit whole constellations.
No. Other stars have been found to have planets orbiting them.
No, there are circular movements just about anywhere: planets, moons and stars rotating, planets orbiting their stars, moons orbiting their planets, and stars orbiting their galaxies, often in orbits that are fairly circular, etc.
the planet makes a dim in the light given star
All the planets we know of... even those orbiting other stars... are in the Milky Way Galaxy.
That depends on which solar system and planet you are asking about - we now know for planets orbiting other stars.
Extrasolar planets are planets found orbiting stars other then our own.
No. Dwarf planets orbit stars just like planets do. Stars orbit the center of their galaxy. An object orbiting a planet would be a moon.
A solar system comprises a star (or combination of gravity bound stars) and their orbiting planets. We think the majority of stars are solar systems an we have detected planets orbiting stars other than the Sun. However in the process of forming a solar system we believe that planets my be permanently ejected from orbiting their stars and flung off into interstellar space. These planets would therefore indeed be outside any solar system.
Planets cannot have stars orbiting them by definition.