Deciphering General Characteristics

One aspect of this research that I find very interesting is that we may be discovering enough planets so that we can begin to decipher some of the general characteristics of the population. This means that we can begin to address important questions, like how do planets form, and how do their orbits evolve, and what are the implications for finding rocky planets like our own in comfortable, stable orbits? But, the number of discovered systems is still woefully inadequate for this kind of interpretation to be reliable, and the selection effects are severe and dangerous. Thus, one of the main activities underway now is to carry out an initial reconnaissance of large samples of stars, to identify additional systems in large numbers, and to explore how the frequency and characteristics of planets depend on parameters such as the mass of the primary star, or its metallicity. Probably the best facility in the world right now for this kind of work is located in Hawaii, halfway to space (as the Hawaiians like to say) on the summit of Mauna Kea. Keck I, the first of the two 10-meter telescopes (Figure 4) and the marvelous High Resolution Echelle Spectrograph built by Steve Vogt, are getting heavy use for planet searches and follow-up studies, supported primarily by NASA. Several large Doppler surveys are underway with this facility and with others around the world, and thousands of stars are being monitored. We can expect to see announcements of dozens of new planets over the next several years.

Figure 4. Keck I

Contributed by: Dr. David Latham