This node contains data from the fifth data release (DR5) of SDSS. The Sloan Digital Sky Survey is the most ambitious astronomical survey ever undertaken. The survey will map one-quarter of the entire sky in detail, determining the positions and absolute brightnesses of hundreds of millions of celestial objects. It will also measure the distances to more than a million galaxies and quasars. The SDSS addresses fascinating, fundamental questions about the universe. With the survey, astronomers will be able to see the large-scale patterns of galaxies: sheets and voids through the whole universe. Scientists have many ideas about how the universe evolved, and different patterns of large-scale structure point to different theories. The Sloan Digital Sky Survey will tell us which theories are right - or whether we will have to come up with entirely new ideas.
The USNO-B1.0 Catalogue presents positions, proper motions, magnitudes in various optical passbands, and star/galaxy estimators for 1,045,175,762 objects derived from 3,648,832,040 separate observations. The data were taken from scans of 7,435 Schmidt plates taken from various sky surveys during the last 50 years. The catalogue is expected to be complete down to V=21; the estimated accuracies are 0.2arcsec for the positions at J2000, 0.3mag in up to 5 colors, and 85% accuracy for distinguishing stars from non-stellar objects
