To search the database, select one of the following tools
Search the sky around a given point (EASY)
Search the sky in a rectangular region (EASY)
- Search Form:
Search the sky by selecting choices from an online form (EASY)
- Query Builder:
Build a SQL query by clicking on various menus (HARDER)
Type in a SQL query directly (HARDEST)
Search Tools for scientists
The names and units of fields on the query pages
- ra, dec are the sky coordinates of the search.
- They can be entered either in
degrees or in the h:m:s, d:m:s notation.
- radius is the search radius for a radial query.
- It is measured in minutes of arc.
- u,g,r,i,z are the magnitudes of the objects in the SDSS.
- These represent the fluxes of light measured in logarithmic units, through various wavebands
from the ultraviolet to the infrared
The output options and formats on the query pages
- Return: the number of objects
- Selecting all will return all objects
- Selecting top N will return the first N objects satisfying the query
- Format: the output format
- It can be HTML, when a formatted web page is returned
- It can be CSV, when a comma separated, unformatted text is returned, with one header line
and subsequent objects in a new line, attributed separated by a comma
- It can be XML, not yet implemented
Getting FITS files from the DASYou can easily retrieve the raw FITS file data corresponding to your query using any of the CAS search tools.If the necessary columns are included in the SELECT part of your query, the appropriate button will automaticallyappear on the query results page (below the query results) to allow you to upload the appropriate information to the DAS (Data Archive Server). These columns are part of the default query ineach of the search tools, but if you modify the default query or enter your own query, be sure to include the following columns:
- run, rerun, camcol, field from the PhotoObj (or PhotoTag) tables if you want imaging FITS data from the DAS;
- plate, mjd, fiberid from the SpecObj or SpecPhoto tables if you want FITS spectra from the DAS.