| Studying circumstellar disk evolution and planet formation around other stars provides a context for the formation and the uniqueness of the solar system and the Earth in particular. In this thesis, we investigate circumstellar disk evolution and terrestrial planet formation from a comprehensive, multiwavelength survey of the massive double cluster, h and chi Persei. Spitzer IRAC/MIPS observations of disks surrounding h and chi Per stars exhibit a stellar mass/spectral type-dependent frequency of warm circumstellar dust emission, consistent with the planet formation process running to completion faster (slower) for high (intermediate/low) mass stars. These stars also exhibit a wavelength-dependent frequency of circumstellar dust emission from K band through 24 microns, a result consistent with planet formation running to completion fastest from the inside out. Spectroscopy is used to constrain the stellar population of the Double Cluster, specifically chi Persei and to identify accreting sources. We derive an extinction of E(B-V) 0.56, a distance modulus of 11.85, and an age of 14 Myr +/- 1.5 Myr for chi Persei, in agreement with previous, more shallow surveys. We find evidence for a low-density halo population of sources surrounding both h and chi Persei that is about as populous as the core regions and may have a slightly larger 5 Myr age spread. Detailed modeling of IRAC-excess sources reveals that many, if not most, of them are not optically-thick primordial disks or transitions disks but warm (250-400 K) debris disks, indicative of terrestrial planet formation. The majority of known stars with ongoing terrestrial planet formation are now found from this survey. Many sources also have much colder dust populations (50-200 K), revealing evidence for planet formation at larger stellocentric distances and a wide range of dust clearing in disks. Finally, we compare results for h and chi Persei with that for other 5 Myr--1 Gyr clusters with debris disks to provide a picture of the evolution of debris emission from planet formation. The 24 micron excess from debris disks 'rises' from 5 to 10 Myr, peaks from 10--20 Myr and 'falls' from 20 Myr onwards. Future observations, especially from Spitzer and JWST, will provide a thorough study of planet formation in the most massive evolved open cluster within 2.5 kpc of the Sun. |
