Methods Of Discovering Extra solar Planets. Elliot Thompson

Methods to detect Extra solar Planets There are many methods to detect Extra Solar planets. They are known as: Astrometry, Wobble Detection, Radial Velocity, Transit Photometry, Direct Imagining, and Chorography.

The problems of finding Extra Solar planets! Some of the problems to find planets around other stars is that they give off no light. Some of the others are they are small compared to the star and the affects on the star are small. Lastly the methods aren’t able to detect earth planets yet. (easily)

Method 1: Astrometry. Astrometry is a branch of astronomy. What these dudes do is they measure the position and the movements of stars. To use these movement they look at star to see if it is moving. If its not moving than the star might not have a planet(s). Basically they look for an abnormality in the stars movement. To use this method is that they need to have the movement down for the star they are looking at. If the star is moving in a strange way then a planet could be there. (see next slide)

Method 2: Wobble Detection This method goes hand in hand with the astrometry. Once they find out the stars movement, then they look for if the star is moving in real life. The affects of the planet will be small yet it will be detectable. Of course large planets will be doing this affect. The downside to this is that large planets could be doing the wobble dance.

Method 3: Radial Velocity! Radial Velocity is one of the motions of the star does known as stellar motion. Radial Velocity is use in redshift. As it will be altered slightly when a planet goes by. To use radial velocity astronomers look for an altercation in the movement of the star, Possibly from a planet. Radial velocity can only detect large planets or planets close to the star itself.

Method 4: Transit Photometry! This method is rarely used, by that the planet and the star must be aligned in the direction astronomers are looking at. That is the only time astronomers used this method, but it is vital and can be used if needed.

Method 5: Direct Imagining! This method needs the other four in order to use the method to the full extent. This method is difficult since the planet is small compared to the star and will be hard to find since light will be a factor.

Method 6: Coronagraph! We all know the stars have a corona and can be detect with telescopes. To use this method they look at the corona of the star to see if its being block from a planet.

What has been detected. The planets so far that has been detected are large planets. The large planets are mostly gas giants close to the star. they are known as “Hot Jupiters”. Super earths has been detected.

What are hot jupiters? Hot jupiters are gas giants that is close to the star and very hot. The average temperature of this hot giants range from 1,700 to 1,200 degrees F. The hot Jupiters can orbit the wrong way. What it means the star will be going one way while the planet goes the other way. To make thing even weirder the jupiters rotation is in tide lock. Tide lock means they don’t rotate. One side will always face the star.

What are super Earths? A super earth is one of the detected planets that has been detected using the methods of this piece. Super earth are bigger than the earth itself. How big will 2, 5 or 10 time the mass of the earth. Of course the super earths may not hold life. They could be close to the sun or they could be away from the inhabited zone.

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