The Digitized Sky Survey is a collection of scanned photographic images from the Palomar Observatory Sky Survey and the Anglo-Australian Observatory (AAO). These digital images were used by the Space Telescope Science Institute to create the Hubble Guide Star Catalog (GSC), a large database of stars and other celestial objects. With this database, the Hubble Space Telescope is able to accurately locate, track and photograph celestial objects.

RealSky CDs 1-8 contain images of the entire Northern Hemisphere down to 15 degrees south declination. CDs 9-18 contain the Southern Hemisphere from 90 degrees declination to three degrees north. The images accessed using the Software Bisque’s image processing application called CCDSoft, or RealSkyView.

The Digitized Sky Survey (DSS) originally filled 102 CD-ROMs, its data covering the entire celestial sphere. This new release is compressed by a factor of 10, so the original digitized data from scanning the Palomar and AAO plates comprised over 100 CD-ROMs of data. The complete 102 CD-ROM set can be purchased from the Astronomical Society of the Pacific (ASP).

What is the Real Sky Data?

By using sophisticated compression techniques, the Space Telescope Science Institute was able to compress the original Digitized Sky Survey by a factor of 100. The resulting data now fits on 18 CD-ROMs and is called the RealSky data. RealSky is an indispensable tool for anyone actively involved in monitoring or studying the heavens.

RealSky provides data to answer questions and quickly show areas of the night sky on your computer screen. Imagine owning a desk reference with stars and other objects down to 19 magnitude! Have you ever wondered what a particular NGC object actually looks like? With RealSky, the actual photograph is just a mouse click away.

What is RealSkyView?

RealSkyView is an application provided with the RealSky CDs for accessing and displaying the RealSky data. It also provides basic image processing functions enhancing these images. Using RealSkyView, you can specify a set of equatorial coordinates, along with image dimensions in arc-minutes (called a target), and RealSkyView will prompt you to insert one of the eight data disks. The image is created and displayed on your computer screen.

RealSkyView can also be run in the background as an OLE "server" application. This provides the functionality needed by applications like TheSky for linking RealSky images to catalog data and labeling these digital images with catalog numbers, and star magnitudes.

CCDSoft, Software Bisque’s image processing software for controlling CCD cameras, has all of the capabilities of RealSkyView and can also be used to generate images from the RealSky CDs.