June 5, 2020 7-9PM

Event Type: Lecture and Stargazing
Title: Measuring the Speed of Stars More Precisely Than Your Car’s Speedometer
Lecturer: Ryan Rubenzahl
Position: PhD Candidate
Institution: Caltech
Abstract:
The “doppler method” or “wobble method” of detecting planets orbiting other stars, requires precise measurements of the speeds of those distant stars. If we can see a star oscillating towards and away from us, we can infer that an unseen planet is tugging on its parent star as it orbits. This method successfully found the first exoplanet, 51 Peg b, a discovery which earned the Nobel Prize this last year. We now know of over 4000 exoplanets, but we are just on the verge of being able to detect Earth-like planets in the “habitable zones” of Sun-like stars. In this public talk we will learn just how hard it is to precisely measure the speeds of stars to the precision of 9 cm/s (0.2 mph!!!) necessary for finding these Earth-like planets. Next-generation instruments capable of these discoveries may finally be able to answer the question of how common planets like Earth really are in the galaxy.