Flattened, rotating disks of cool dust and gas extending for tens to hundreds of astronomical units are found around almost all low-mass stars shortly after their birth. These disks generally persist for several million years, during which time some material accretes onto the star, some is lost through outflows and photoevaporation, and some condenses into centimeter- and larger-sized bodies or planetesimals. Through observations mainly at IR through millimeter wavelengths, we can determine how common disks are at different ages; measure basic properties including mass, size, structure, and composition; and follow their varied evolutionary pathways. In this way, we see the first steps toward exoplanet formation and learn about the origins of the Solar System. This review addresses observations of the outer parts, beyond 1 AU, of protoplanetary disks with a focus on recent IR and (sub)millimeter results and an eye to the promise of new facilities in the immediate future.
Annual Review of Astronomy and Astrophysics
- Pub Date:
- September 2011
- Astrophysics - Galaxy Astrophysics;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics
- 65 pages, 11 figures, published in volume 49 of the Annual Review of Astronomy and Astrophysics, based on the available literature up to the end of 2010. We recommend that you retrieve the published paper from Annual Reviews for greatly improved figures and typesetting