Join the Search For Extrasolar Planets!

I wanted to use today’s blog entry to tell you about an innovative Web site that enables anybody with an Internet connection to engage in exciting, cutting-edge scientific research.

While astronomers continue to debate the definition of “planet” for objects inside the solar system, this Internet site allows you to join the hunt for planets around other stars. As he explains in S&T’s October 2006 issue, University of California, Santa Cruz, astronomer Greg Laughlin and his colleagues have developed the Systemic Project Web site, which allows users to search for extrasolar planets using published radial-velocity data taken by the California/Carnegie group led by Geoff Marcy, Paul Butler, and Debra Fischer, and the Geneva team led by Michel Mayor.

This is no joke. If you’re willing to invest some time and brainpower at this site, there is a distinct possibility that you could discover an actual planet orbiting another star. Since you’re reading this blog article, it means you have everything you need to participate: access to a computer and the Internet, and an interest in astronomy. No telescope or other instruments are required.

Greg and his colleagues have developed a console that allows participants to search for planets by moving banks of sliders (like one would find in an audio mixing board) to adjust for different possible planet masses, orbital periods, etc. to see if one can match up a model radial-velocity curve to the host star’s measured radial velocities. The Systemic team has also developed special tools to enable users to dig out planets in complex systems with multiple worlds. All of this is described in a user-friendly tutorial that can have a typical participant up and running in one hour.

How is this possible, you might ask? There are so many interesting planetary systems out there waiting to be deciphered, and the amount of computation is so extensive, that the professionals who are conducting these searches simply don’t have the time to analyze all of the data they are collecting. They have done the technically difficult job of obtaining the radial-velocity data (which can reveal the gravitational influence of orbiting planets), and they have generously published it in publicly accessible journals. Greg and his Systemic colleagues have combined some of these data sets for the first time, enabling users to find planets that are ripe for the picking.

The 4-planet configurations around the stars 55 Cancri and Mu Arae are of particular interest. Greg points out that the orbital solutions published in the professional literature for each star are not the end of the story. The data suggest that there are additional planets in these systems that a dedicated amateur could uncover.

In the months ahead, Greg and his Systemic team will allow participants to search for “synthetic planets” in simulated data sets, which will allow the professionals to learn about potential biases and other problems that might plague the real data sets. Starting this Sunday and running until the end of September, the Systemic team will post a synthetic “Star of the Week” on its Web site. The first person to successfully crack each week’s system will win a copy of our Millennium Star Atlas. To see the contest URL, pick up a copy of the October 2006 S&T and turn to page 41. If you’re not a subscriber, the issue will be on newsstands no later than next Tuesday.

Of course, the International Astronomical Union last week approved a poorly conceived definition of "planet," which applies only to bodies around the Sun. So according to the IAU, none of these worlds around other stars are “official” planets. But putting that bit of IAU absurdity aside, please note that the lion’s share of the credit for any discovery made through the Systemic project should and will go to the astronomers who took the data. But imagine the life-long satisfaction you’ll receive if you play a direct role in finding a planet around a distant star. Give it a whirl!