SF State Magazine { University Communications }

Image: Photos of SF State students and scenes from around campus

How Does it Feel to Find a Planet?

Image of a silhouetted figure looking through a telescope.

Finding planets around other stars has been a holy grail for hundreds of years, dating back to Tycho, Kepler and Galileo. Back then the field was hot. Really hot. So hot that Giordano Bruno was publicly burned at the stake in part for suggesting that stars were like the Sun, and likely had planets and intelligent beings.


I began working on planet detection in 1986, starting in the SF State chemistry lab, playing with colored gases, a funky lot that typically explode or melt your lungs at very low concentrations. After spending years working on the problem of pulling out the tiny signal of a planet orbiting a massive star, it occurred to me that this quest might be like other holy grails, destined to end in ignominious failure.


In November 1994 my colleague Steve Vogt upgraded his Hamilton Spectrograph at Lick Observatory, vastly improving the quality of raw data that could be collected. By May 1995 my analysis code was locked in, producing world-class precision.


In October 1995 a Swiss team announced a giant Jupiter-like planet orbiting a nearby star. This announcement was doubly amazing because the planet circled the star every four days, unlike anything ever dreamed of. With four nights on the Lick telescope the following week, there was just enough time to confirm this discovery. We had eight years of data on 120 stars, but with just two computers, it would have taken a decade to reduce our data. In the wake of the Swiss discovery, several groups provided computers on loan. I began living in the office, keeping the computers grinding 24-7 for the next nine months.


At 7 a.m. on New Years Eve 1995 I was inspecting the latest star to emerge from our data trove. It had a whopping signal, the observations falling gloriously along a Keplerian curve, the unique signature of planetary motion. The office was a silent void.


For the longest time I was speechless, staring at the data slung along the computer screen. I had the distinct feeling that Kepler himself was standing over my shoulder and smiling in silent satisfaction.


-- Paul Butler (B.S., '86; M.S., '88) is a staff scientist with the Carnegie Institution of Washington, Department of Terrestrial Magnetism. His work has led to the discovery of about half of the known extrasolar planets.

Return to "How Does It Feel?" index




Share this story:



SF State Home