Japanese version Home Page Updated on September 30, 2002
USNO-A2.0 data around R.A. 18 hour, Decl. -10 degThe pattern of stars on an image almost corresponds to that on a star chart in most regions, even if in the Milky Way. Here introduces the example of an image at R.A. 18 hour, Decl. -10 deg. Here is the unfiltered CCD image of this region taken by KenIchi Kadota. 
Examining this image using the PIXY System 2, it shows a chart of detected stars, and another chart of the same area plotting the USNO-A2.0 data. Here is the result. A green star is a normal one, detected from the image, and also recorded in the USNO-A2.0. A red star on the "Detected Stars" chart is one detected from the image, but not recorded in the USNO-A2.0. A red star on the "USNO-A2.0" chart is one recorded in the USNO-A2.0, but not detected from the image. Most of the stars are plotted in green color. 
NOTE: The stars on the USNO-A2.0 chart are plotted based on the magnitude converted by the Taichi Kato's formula: V = R + 0.375 * (B - R) |