The Ninth SDSS Data Release (DR9)

DR9 Facts
Sky coverage	14,555 square degrees
Catalog objects	932,891,133
Galaxy spectra	1,457,002
Quasar spectra	228,468
Star spectra	668,054

Data Release 9 (DR9) offers the latest data from the Sloan Digital Sky Survey. Data Release 9 is the first release of the spectra from the SDSS-III's Baryon Oscillation Spectroscopic Survey (BOSS), which includes more than 800,000 spectra over 3,300 square degrees of sky, observed with the new 1,000-fiber BOSS spectrograph.

Data Release 9 also includes all imaging and spectra from prior SDSS data releases, and provides corrected astrometry for the imaging from Data Release 8.

DR9 also includes better stellar parameter estimates, provided by an updated SEGUE Stellar Parameter Pipeline (SSPP). The principal changes from DR8 are summarized in the What's New in DR9.

Imaging coverage check
RA Dec

Enter the RA/Dec position in decimal degrees or in the format HH:MM:SS / ±DD:MM:SS. Results will appear in the white space below.

DR9 sky coverage
(click for a larger version)

Using DR9

The figure to the right shows the sky coverage of DR9. The form to the right allows you to find whether a sky position (RA and Dec in decimal degrees or HH:MM:SS / ±DD:MM:SS) is contained within the DR9 survey area.

The Scope of DR9 provides more detailed information about DR9 sky coverage, and includes a coverage check form that links directly to SDSS imaging and spectroscopic data.

The items in the menubar above contain the following information about DR9:

What's new? explains the differences between DR9 and previous data releases.
Scope describes what data are available in DR9, including sky coverage, data size, and resolution information.
Data Access shows how to get common types of SDSS data, and provides links to all SDSS data access tools. This is the best place to look for a quick start using SDSS data.
Imaging explains what imaging data DR9 contains. It also provides details on the SDSS imaging pipeline, the calibration process, and what quantities (including units) are available in the catalog data.
Spectra explains what spectroscopic data are available, and provides details on further data including target flags, redshifts, and classifications.
Algorithms lists some of the principal SDSS-III data processing algorithms, including target selection, and contains complete detail on how the algorithms work.
Software provides download instructions and documentation for a variety of software tools for working with SDSS data.
Help contains a glossary, Frequently Asked Questions, and other resources to help you get started in using DR9.
Tutorials provide step-by-step guides to common research and teaching tasks using SDSS data. This is a good place to look for guidance in doing your science with the SDSS.

Complete details about DR9 are documented on this site and in the Data Release 9 paper (Ahn et al., 2012, ApJS, 203, 21).

Acknowledging DR9

Publications using SDSS data are required to include the complete official SDSS-III acknowledgment. Data from the SDSS-III public archive may not be used for any commercial publication or other commercial purpose except with explicit approval by the Astrophysical Research Consortium (ARC). Requests for such use should be directed to the ARC Corporate Office via ARC's Business Manager:

Michael L. Evans

ARC Business Manager

c/o University of Washington, Department of Astronomy

Box 351580

Seattle, WA 98195

Phone: 206-685-7857

email: evans -at- astro dot washington dot edu.