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DSS

The DSS object detail tab page allows you to view a Digitized Sky Survey (DSS) image centered on the selected object's coordinates. DSS images are black and white or color.

Important: DSS images are linked to an object according to its position in the sky. Deep-sky and stellar objects do not move quickly enough to invalidate the link to an image stored on the local hard drive. However, asteroids, comets and planets move constantly, so the links to their images become invalid quickly. Thus, downloading images and saving them to your local hard drive for these types of objects leads to images that are only used once. The best strategy to use for these types of objects is to use the Refresh button to download (but not store) images for asteroids, comets and planets.

Several status items are shown at the top of the tab as follows:

▪No Image indicates that no link is defined to online (DSS server & survey) storage for an image of the object. To define a link, visit the DSS tab in Preferences and choose server, survey and size defaults. You may need to select the object in the report pane again to have its image and status updated.

▪Local Image indicates that the image being displayed was retrieved from local storage. The original link used to acquire the image is displayed above this status. For example poss2ukstu_red (15') indicates that the image belongs to the DSS-2 Red survey and the image is 15 arcminutes square. See Digitized Sky Survey Overview for more information regarding servers and surveys. You may click the button to fetch (download) the image and display it. Fetch does NOT store the image file.

▪Click Refresh to fetch image indicates that a link is defined for an image that is not stored locally but may be retrieved from online storage. Click the button to fetch (download) the image and display it.

▪Online Image indicates that the image being displayed was retrieved (downloaded) from online storage and is not stored locally. The link used to acquire the image is displayed above this status as described above. Click the button to save the downloaded image to local storage. The image file is NOT stored locally unless you click .

opens this help topic.

Processing

Simple processing can be applied to an image while you view it, but a processed image cannot be stored. Processing options include:

▪Invert Colors: reverse colors; for example, black stars on white background

▪Rotate Image +90°: rotate the image clockwise

▪Rotate Image -90°: rotate the image counterclockwise

▪Flip Horizontal: flip the image right to left

▪Flip Vertical: flip the image top and bottom

▪Revert Changes: view the original image and delete all processing changes