Exploring Young Brown Dwarfs

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

AST-0205130 PI Jayawardhana The past five years have seen the identification of a large number of sub-stellar objects in the solar neighborhood and in star-forming regions. Indeed, it appears that brown dwarfs may be as common as stars. However, there are few observational constraints on their origin and early evolution. Studies of young brown dwarfs provide valuable clues to their formation mechanism(s). This program explores the physical properties of brown dwarfs in star-forming regions and compare them to the much better studied pre-main sequence stars, in order to shed light on their origin. The program employs many of the methods developed in the study of T Tauri stars, and includes (1) a search for thermal infrared emission from disks around young sub-stellar objects, (2) optical spectroscopy to derive their accretion luminosities and mass accretion rates, (3) modeling of scattered light and thermal emission of disks, (4) observations of X-ray emission, as an indicator of activity, and (5) measurements of rotation periods based on photometric variability in the optical. The results of this program will help distinguish among different formation scenarios for brown dwarfs, such as cloud fragmentation, protostellar disk instability, and ejection from newborn multiple systems, whether young sub-stellar objects undergo a T Tauri-like phase. ***