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Counting Stars in Astronomical Images with Registar

The Registar software program performs an operation that identifies point sources (i.e., stars) which is used by the program to map star locations for subsequent image registration operations.  The program counts the number of stars located, which while not particularly useful otherwise, is fun and interesting on those really deep and heavily populated star fields which overwhelm you by the number of stars present.  Have you ever wondered just how many stars there are in an image?  Here's how to find out.

The processing steps are simple as outlined below.  The commands in parentheses are keyboard shortcuts.

The number of stars counted is displayed as a running total in the program's lower status bar as the image is processed.  The final star count is displayed at the bottom of the Image Properties dialog box.

Using VIEW>SELECT>STARS ONLY (S), the nebulosity and flares around stars are masked and only the point sources the program uses to count the stars is displayed.  Return to the raw image with VIEW>SELECT>NORMAL (N).

Normal display of the image when first loaded.

The point sources can be displayed without image nebulosity using VIEW>SELECT>STARS ONLY (S) after processing the image

with the LOCATE STARS  (F3) operation.

The Image Properties dialog box displays the number

of stars identified in the image.

If you don't have Registar, mail me your image and I'll count your stars for you.

Example astrophoto supplied with Registar software.