Sloan Digital Sky Survey

The Sloan Digital Sky Survey or SDSS is a major multi-spectral imaging and spectroscopic redshift survey using a 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States. The project was named after the Alfred P. Sloan Foundation, which made much of the funding.

Sloan Digital Sky Survey Media

• Quasars acting as gravitational lenses. To find these cases of galaxy–quasar combinations acting as lenses, astronomers selected 23,000 quasar spectra from the SDSS.

• Light from distant galaxies has been smeared and twisted into odd shapes, arcs, and streaks.

• LRG-4-606 is a luminous red galaxy. LRG is the acronym given to a catalog of bright red galaxies found in the SDSS.