Using a telescope that you control online, you'll take images of distant solar systems, interpret the data you gather, and become of the few humans to detect a planet orbiting a star far beyond our own Sun. In this Laboratory, you will attempt to detect and describe some of these alien worlds, from among the two thousand planets already known or suspected by astronomers.
These planets are too distant to see directly. You'll have to use your knowledge of science to find them. Your strategy: You'll follow the brightness of the planet's host star over the course of an evening. As the planets orbits in front of the star, blocking some of its light, the star will appear to dim slightly. By charting the brightness of the star, you'll look for a dip in its brightness… the telltale sign of an orbiting planet.
Once you find your planet, you'll be able to figure out some of its properties – how big it is, how close it is to its star, and even whether its orbit is tilted.
In this lab you'll learn how to detect an alien planet. And you'll learn how to figure out some of its properties — such as how large and how hot it is. Use physical models and computer-based models to predict: How will the observed brightness of your star change as a planet orbits in front of it? How will the size and orbit of the planet affect your observations?
You'll choose a star to investigate. Then you'll control the robotic telescope, telling it to take images at the times you select. During the night the telescope will point to the star you requested, take the images, and send them to your online account by the next morning. There is no human in the loop… just you!
Retrieve your images and inspect them. Did they come out? You'll measure the brightness of your chosen star in each image you took. Then you'll graph the brightness of the star over time. Can you detect a dip in brightness that might be the sign of another world? How will you be sure?
From your data, you can figure out the size of the planet you've detected; the nature of its orbit; its distance from its star; and the planet's distance from Earth. You'll interpret and reflect on what your findings might mean.
Using your findings, create a first portrait of your alien world and its host star. Compare this distant exo-system to our own solar system.
To tell what the surface of your planet is like, you'll need to decipher the light coming the planet itself. Learn what a spectrum is. Learn how to decode a single pixel of light. In principle, it can tell you whether a planet has oceans, continents, seas, clouds, seasons, even what its atmosphere is like and whether its has life.
Once your class has completed the ExoLab investigations, you can publish your data for the world to see. Compare your results to those of other exoplanet searchers in the community.