page_title: Sloan Digital Sky Survey
section_title: Data access
hierarchical_section_title: Sloan Digital Sky Survey / Data access
caption_attribution_description: English: This NASA/ESA Hubble Space Telescope image shows remarkable structures in a galaxy cluster around an object called LRG-4-606. LRG stands for Luminous Red Galaxy, and is the acronym given to a large collection of bright red galaxies found in the Sloan Digital Sky Survey (SDSS). These objects are mostly massive elliptical galaxies composed of huge numbers of old stars. It is sobering to contemplate the sheer number of stars that this image must contain — hundreds of billions — but it also features one of the strangest phenomena known to astronomers. This particular red galaxy and its surrounding galaxies happen to be positioned so that their strong gravitational field has a dramatic effect. Left of centre in the picture, blue galaxies in the background have been stretched and warped out of shape into narrow, pale blue arcs. This is because of an effect called gravitational lensing. The galaxy cluster has such a strong gravitational field that it is curving the fabric of space and amplifying the starlight from much more distant galaxies. Gravitational lensing normally creates elongated arcs and here, unusually, the alignment of the galaxies has made the separate arcs combine to form a half-circle. This picture was assembled from a collection of exposures in visible and near infrared light taken with Hubble’s Wide Field Camera 3. The field of view is approximately 3 by 3 arcminutes.
context_page_description: The Sloan Digital Sky Survey or SDSS is a major multi-spectral imaging and spectroscopic redshift survey using a dedicated 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 contributed significant funding.
  Data collection began in 2000; the final imaging data release covers over 35% of the sky, with photometric observations of around nearly 1 billion objects, while the survey continues to acquire spectra, having so far taken spectra of over 4 million objects. The main galaxy sample has a median redshift of z = 0.1; there are redshifts for luminous red galaxies as far as z = 0.7, and for quasars as far as z = 5; and the imaging survey has been involved in the detection of quasars beyond a redshift z = 6.
  Data release 8, released in January 2011, includes all photometric observations taken with the SDSS imaging camera, covering 14,555 square degrees on the sky. Data release 9, released to the public on 31 July 2012, includes the first results from the Baryon Oscillation Spectroscopic Survey, including over 800,000 new spectra.
context_section_description: The survey makes the data releases available over the Internet. The SkyServer provides a range of interfaces to an underlying Microsoft SQL Server. Both spectra and images are available in this way, and interfaces are made very easy to use so that, for example, a full color image of any region of the sky covered by an SDSS data release can be obtained just by providing the coordinates. The data are available for non-commercial use only, without written permission. The SkyServer also provides a range of tutorials aimed at everyone from schoolchildren up to professional astronomers. The tenth major data release, DR10, released in July 2013, provides images, imaging catalogs, spectra, and redshifts via a variety of search interfaces.
  The raw data (from before being processed into databases of objects) are also available through another Internet server, and first experienced as a 'fly-through' via the NASA World Wind program. 
  Sky in Google Earth includes data from the SDSS, for those regions where such data are available. There are also KML plugins for SDSS photometry and spectroscopy layers, allowing direct access to SkyServer data from within Google Sky.
  The data is also available on Hayden Planetarium with a 3D visualizer.
  There is also the ever-growing list of data for the Stripe 82 region of the SDSS.
  Following from Technical Fellow Jim Gray's contribution on behalf of Microsoft Research with the SkyServer project, Microsoft's WorldWide Telescope makes use of SDSS and other data sources.
  MilkyWay@home also used SDSS's data for creating a highly accurate three dimensional model of the Milky Way galaxy.
caption: LRG-4-606 is a Luminous Red Galaxy. LRG is the acronym given to a catalog of bright red galaxies found in the SDSS.
exif: {"Image ImageDescription": "This NASA/ESA Hubble Space Telescope image shows remarkable structures in a galaxy cluster around an object called LRG-4-606. LRG stands for Luminous Red Galaxy, and is the acronym given to a large collection of bright red galaxies found in the Sloan Digital Sky Survey (SDSS). These objects are mostly massive elliptical galaxies composed of huge numbers of old stars. It is sobering to contemplate the sheer number of stars that this image must contain \u2014 hundreds of billions \u2014 but it also features one of the strangest phenomena known to astronomers. This particular red galaxy and its surrounding galaxies happen to be positioned so that their strong gravitational field has a dramatic effect. Left of centre in the picture, blue galaxies in the background have been stretched and warped out of shape into narrow, pale blue arcs. This is because of an effect called gravitational lensing. The galaxy cluster has such a strong gravitational field that it is curving the fabric of space and amplifying the starlight from much more distant galaxies. Gravitational lensing normally creates elongated arcs and here, unusually, the alignment of the galaxies has made the separate arcs combine to form a half-circle. This picture was assembled from a collection of exposures in visible and near infrared light taken with Hubble\u2019s Wide Field Camera 3. The field of view is approximately 3 by 3 arcminutes.", "Image Artist": "", "Image Copyright": ""}