Visual Tools

The visual exploration tools built for the SkyServer make it easy to visualize and explore detailed astronomical data in regions of the sky covered by the Sloan Digital Sky Survey. One can specify regions of interest by central position and size. An underlying web service then combines the relevant images to form a JPEG mosaic* at the requested wide range of resolutions. One can overlay additional useful information, including:

  • boundaries of survey fields and aperture plates,
  • outlines of individual objects and data quality masks, and
  • locations of photometric and spectroscopic objects.
The tools can also search for lists of known objects, provide links for detailed information, and formulate new database queries.

*Note: The Finding Chart, Navigate and Image Lists tools build mosaics on the fly by overlapping SDSS fields that may or may not belong to different runs . The field area displayed in the overlap region is determined by the (arbitrary) order in which the fields are being superimposed by the mosaicing software. However, the sky may have changed from one run to the next. Observations of moving or variable objects like meteors, satellites, comets, variable stars, etc. may appear in one run but not in the other, or be different from one run to the other. We suggest that if you want to carefully examine any object(s) close to a field boundary, you should use either the Get Image by Field tool which displays the whole JPEG frame for individual fields in each run, or get the FITS file from the Explorer or the Science Archive Server .


  • Finding Chart
    The page returns a JPEG image centered on (ra,dec), of size (height x width) where the image is scaled to an arbitrary scale (scale). Various drawing options can be specified (opt). Please see Getting Started with Finding Chart.
  • Image List
    This page can generate thumbnails of SDSS images based upon a user defined list of object positions. The images are linked to the other tools. The list can also be specified with a query. Please see Getting Started with Image List.
  • Quick Look
    The Quick Look Tool contains basic data for an object - its position, magnitude, and redshift
  • Explore
    The Explore Tool contains a summary of an object, and interactive links to further detailed properties, like its spectrum or neighbors, etc.


For more information about how the JPEG images on SkyServer are generated, see the JPEG images on SkyServer documentation on www.sdss4.org.