Back to Volume
Paper: Science Opportunities with Microarcsecond Astrometry
Volume: 194, Working on the Fringe: Optical and IR Interferometry from Ground and Space
Page: 1
Authors: Spergel, D. N.
Abstract: SIM will be able to measure proper motions of a few microarsecond/year and parrallaxes of a few microarcseconds. This capability will enable astronomers to address a wide range of scientific problems. Parrallax measurements will enable astronomers to determine the distances to stars. Proper motions measurements will enable astronomer to measure the accelerations experienced by stars. With improvements in astrometric accuracy, astronomers will be able to address scientific questions in fields ranging from planetary astronomy to cosmology. SIM will be capable of detecting Earth-like planets around the nearest stars and larger planets out to tens of parsecs. Through microlensing, SIM will be able to measure the mass of nearby stars. Its accurate distant measurements will determine the absolute luminosity of stars. The combination of these measurements will test stellar evolution theory at high precision. SIM'smeasurement of stellar proper motions will enable dynamicists to infer the mass distribution of the Galaxy and learn about its formation and dynamical evolution. By determining accurate distances to globular clusters, SIM will constrain the age of the universe. Its measurements of distances to M31 and the LMC will strengthen our understanding of the distance ladder and improve our measurements of the expansion rate.
Back to Volume