DS9 supports loading catalogs in multiple file formats including VOTables, FITS files, and CSV/TSV ASCII files. Users have complete programmatic control over the marker symbols (different colors for variable sources, different shapes for different classes of objects, etc). Catalog results can be filtered and sorted. Values in the catalog table can be plotted or histogramed. These are not just static displays but are linked to catalog so selecting a row in the catalog highlights the source in the display and the data point in the plot. The same works by selecting points in the plot or selecting sources in the image using Edit ➜ Catalog mode.

DS9 supports multiple frames, limited on by the system resources on your computer. Multiple frames are great for displaying images of the same object at different wavelengths or as in this image multiple images of the same object as a function of time. This image shows 34 individual FITS images obtained from the DART mission archive that have been manually registered to have the same location on the asteroid located in the center of the image. The DART mission logo was added to the display using Illustrate mode.

This mode is activated by going to Edit ➜ Illustrate. This allows users to draw graphical elements that sit on top of all other display elements (frames, contours, regions, catalog markers, etc); these elements are fixed within the display and do not move when images are panned or if the image display area itself is resized. In this example the green region drawn around the source is a standard DS9 region. The call-out lines, the light-curve plot, and the text box in the bottom right corner are all Illustrate mode elements. In this example the plot was itself created with DS9 and exported to a PNG file that was then loaded into an Illustrate mode image shape.

DS9 is not limited to celestial coordinate systems. This image is an RGB composite of extreme ultraviolet SOHO (Solar and Heliospheric Observatory) images in three wavelengths: red = 284 Å, green = 195 Å, blue = 171 Å which highlights structures in the hot solar atmosphere. DS9 supports solar coordinate systems through integration with the AST world coordinate system library enabling accurate interpretation of helioprojective coordinates.

The HEALPIX format is often used to store "all sky" data. This image shows an all-sky cosmic microwave background from the Planck I-Stokes HEALPix FITS map. In this example the HEALPIX file is stored in Galactic coordinates; however, the coordinate grid has been configured to show celestial ICRS coordinates. To maximize the image display area the information panel, panner, magnifier, and buttons have been disabled via the View menu options.

Regions are a core feature of DS9; and they are not restricted to just simple circle, ellipse, annuls, and box shapes. Complex regions can be drawn using polygons with dozens or hundreds of sides. In this example each of these hexagonal-based polygons encloses a minimum flux. This is a Hitomi image of G21.5-0.9.

Usually astronomers use the three separate primary color channels: red, green, and blue, to display data from different energy bands. But with missions like Chandra, the energy values vary continuously. It is possible to arbitrary break this continuum into separate bands, but now there is no need to. Using the Hue Lightness Saturation or Hue Saturation Value color model instead of the RGB color model, energy can be represented as a continuous value (Hue) and then intensity can be represented using lightness and saturation. This Chandra image of Cassiopeia A shows the median color of the events in each pixel as a continuous color Hue going from Red (low energies) to Magenta (highest energies). The structure (intensity) is represented in the Lightness and Saturation layers.