Data Access for SDSS DR9

Data Release 9 includes three types of data: images, spectra, and catalog data (parameters measured from images and spectra, such as magnitudes and redshifts). The SDSS web sites offer several different online data access tools, each suited to a particular need. The primary websites are:

Website	Purpose
www.sdss3.org/dr9	DR9 Documentation (this site)
dr9.sdss3.org	Science Archive Server (SAS) DR9 front end with searchable interactive spectra and image mosaics
data.sdss3.org/sas/dr9	Direct access to the DR9 data files for experts
data.sdss3.org/datamodel	Detailed description of SAS directory structure and file formats and content
skyserver.sdss3.org/dr9	Browsable interface to Catalog Archive Server (CAS) database and simple SQL queries; browsable sky images with associated spectra and catalog data.
skyserver.sdss3.org/casjobs	Advanced CAS database interface for all data releases
api.sdss3.org	Programmatic access to query or retrieve SDSS spectra (FITS or JSON formats)

These are described in more detail on the available tools page. The tables below provide links to the appropriate tools for various common tasks. If your question isn't addressed here, please take a look at the FAQ and/or tutorial help pages. Note that the getting started tutorials might be particularly helpful if you are new to SDSS-III.

If you are having difficulty connecting to any data server, please check the status page for announcements about planned outages.

Data from the SDSS-II Supernova Survey is not available in DR9, but is available in its entirety at the SDSS-II Supernova Survey website.

Images

The SDSS has taken deep images of more than one-third of the entire night sky. You can view SDSS images online for any object or sky position in the survey area, and download images of SDSS fields as FITS files.

I need to...	Tool to use
browse through sky images to look for interesting objects	Navigate
create a finding chart for my telescope using SDSS imaging	Finding chart
download FITS images for a specific SDSS field containing a given object or sky position	Imaging (FITS) Field Search
download FITS images for many SDSS fields	Bulk Imaging (FITS) Search
see thumbnail images for a list of objects	Image List
see thumbnail images of objects that match my search criteria	Image List

Spectra

DR9 includes all spectra from SDSS-I/-II including SEGUE-I/-II, and all BOSS spectra through July 2011

I need to...	Tool to use
know whether SDSS has measured a spectrum for my object	Navigate
see the spectrum for my object	Spectrum Search
get the spectrum for my object	Spectrum Search
get 50,000 spectra	See the bulk download documentation
retrieve SDSS spectra from within a script (e.g. Python, JavaScript...)	SDSS-III API
Know which spectra data files are available	Spectroscopic pipeline description
Understand the format of a specific data file	Data Model

Catalog Data

Catalog data summarize quantities measured from the images and spectra such as magnitudes, redshifts, and object classifications. These are available either from the Catalog Archive Server (CAS) database, or as binary tables in FITS file format.

I need to...	Tool to use
Find all objects which match some simple selection criteria	SkyServer SQL Search
Perform a complicated CPU intensive catalog query	CasJobs
Generate my own database with custom tables of a subset of the SDSS-III data	CasJobs
Understand the CAS database schema	Schema Browser
Download fits files with the catalog data	See the bulk download documentation
Understand the format of a specific catalog data file	Data Model