BOSS's new spectographs take most precise measurements ever made of the era when dark energy turned on

BOSS, the Baryon Oscillation Spectroscopic Survey, the largest component of the third Sloan Digital Sky Survey (SDSS-III), today announced the most accurate measurement yet of the distance scale of the universe during the era when dark energy turned on. BOSS obtained these best-yet measures with the wide-field Sloan Telescope at the Apache Point Observatory in New Mexico, designed especially for galaxy surveys but mounting a spectrograph far more sophisticated than was available to earlier SDSS surveys. The BOSS instrument uses 50 percent more fibers than earlier SDSS runs, each with finer diameter; for more coverage and finer resolution, the new spectrograph incorporates two red cameras using the thick, red-sensitive astronomical CCDs invented and fabricated at Berkeley Lab, as well as two new blue cameras.