Quasars and Exoplanets Flashcards
What are quasars?
Bright radio source that shows large optical red shift
suggesting its very far away.
Whats the most distance measurable object?
Quasars
Whats the current consensus about quasars?
Its a galactic nucleus containing a huge black active hole. This supermassive black hole is constantly taking in matter
What is an exoplanet?
Any planet not in our solar system
Why are exoplanets hard to find?
They orbit stars much brighter than themselves
They are too small to distinguish from nearby stars
What’s a method to find exoplanets?
Doppler shift
How is Doppler shift used to find exoplanets
Measure the emissions from stats that have been red and blue shifted
What effect does an exoplanet have on a star orbit?
A wobble
Why is a wobble caused?
Both the planet and the star are orbiting around a centre of mass of the system.
The planet is further away
What does a wobble cause?
Tiny red and blue shifts on the stars emissions
These can be detected
What are the problems with doppler shift to find exoplanets?
Need to be aligned
Describe the transit method
Measures change in apparent magnitude as an exoplanet travels in front of a star
How does the transit method work?
Some light is blocked which leads to sip in light curve observed on earth. radius of planet can be found.
What are the problems with the transit method?
The odds of an exoplanet being perfectly lined are very low. You can only confirm that the planet is there not rule out the existence of others.
