The Sloan Digital Sky Survey III ( SDSS-III ) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey ( BOSS ) .
This ninth data release ( DR9 ) of the SDSS project includes 535,995 new galaxy spectra ( median z \sim 0.52 ) , 102,100 new quasar spectra ( median z \sim 2.32 ) , and 90,897 new stellar spectra , along with the data presented in previous data releases .
These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July .
In addition , the stellar parameters pipeline , which determines radial velocities , surface temperatures , surface gravities , and metallicities of stars , has been updated and refined with improvements in temperature estimates for stars with T _ { eff } < 5000 K and in metallicity estimates for stars with [ Fe / H ] > -0.5 .
DR9 includes new stellar parameters for all stars presented in DR8 , including stars from SDSS-I and II , as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 ( SEGUE-2 ) .

The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products .
The next data release for SDSS-III will be in Summer 2013 , which will present the first data from the Apache Point Observatory Galactic Evolution Experiment ( APOGEE ) along with another year of data from BOSS , followed by the final SDSS-III data release in December 2014 .