Unveiling the Secrets of Exoplanets: Exploring the Methods of Discovery

Hello everyone,

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I wrote about what is an exoplanet and what is the importance of discovering new exoplanets in the last post on project hope community, you guys really liked it and supported it. So today i want to write about what are the methods scientists follow to discover new exoplanets. I don't think I can write about all the methods, sice there are a lot of methods, so I'm gonna write about few popular methods today, hope you enjoy learning this with me.

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an illustration of HD 209458 b which is discoverd by using transit method

One of the popular methods to discover an exoplanet is by using transit method, In transit method, scientists would observe a star for its periodic dips in its brightness caused by an exoplanet which passes infront of it, just like an eclipse. By calculating the time and strength of the brightness dips of the star, the astronomers can calculate the size and orbital distance of the exoplanet.

One of the popular exoplanet discovered using this method is HD 209458 b also known as osiris which is a jupiter like exoplanet, it was discovered in 1999 when this planet passed infront of its parent's star causing to dip the star's brightness, this planet is also the one of the first exoplanet to have its atmosphere studied in detail.

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Another method astronomers use is doppler method, also known as radial velocity method. In this method, astronomers look for and calculate the slight variation in a star's radial velocity, which is caused by an orbiting planet's gravitational force. By calculating the variation of radial velocy, astronomers can calculate the mass of the exoplanet.

51 Pegasi b is an exoplanet which is also called as dimidium orbits around a star 51 Pegasi which is 50 light years away from earth and it is confirmed that this planet was indeed discovered using radial velocity method when astronomers noticed that the dimidium caused a wobble in 51 pegasi star's radial velocity.

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Another popular method used is direct imaging, in this method, astronomers use telescope to directly capture image of objects in space and confirm the presence of an exoplanet by observing it's trajectory overtime. This method however can be challenging since the exoplanets are fainter than stars and can be distorted by the glare of stars. But advancement in technology have made it easier to capture the images of exoplanets like never before.

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Beta Pictoris b is an exoplanet which is orbiting around Beta Pictoris, and is 63 light years away from earth. This exoplanet was first discovered by images taken by gemini planet imager in 2013, the discovery of this planet enabled astronomers to study various properties of exoplanets and information about formation of larger planets.

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This method is my favourite so far, because it's an interstellar level method, let me know if you like this method or not. This method is called gravitational microlensing, In this method, astronomers looks for gravitational lensing effect. Let me explain, in this effect, a star with greater gravitational force an bend light, just like how black hole bends the light behind it. So the star can bend a light from a distan star which causes the light to magnify. If the star that bends the light had a planet, the planet's gravitational force could distort the magnified light of the distant star. By looking for this effect, astronomers can discover exoplanets.

OGLE-2005-BLG-390Lb is an exoplanet which is discoverd by gravitational microlensing method. This planet is a cold and neptune like exoplanet which is 20,000 light years away from earth, is discovered when astronomers noticed a slight distortion in the magnified light of a distant star by this planet's parent star.

There are a lot of methods astronomers use to discover new planets, I barely scratched the surface, maybe if I found other methods as interesting as this, I'll definitely make post about it. If you have sticked with me till now, I thank you and admire you for your curiosity. I hope i wrote this post in an understandable manner, if you find it hard to understand any methods, please let me know, ill try to correct my mistakes. I hope you learned something new.

Thank you and STEEM ON!