STAR Atlas:PRO frequently asked questions - FAQs

What is the setting "Distinguish Non-Stellar Objects" and how do I use it ?

Both the Guide Star Catalogue (GSC) and the Guide Star Catalogue 2 (GSC 2) consist of two primary types of objects. These are Stellar Objects (i.e. Stars) and Non-Stellar Objects (i.e. sometimes called Non-Stars these objects are extended/diffuse objects such as nebulae).

When the setting Distinguish Non-Stellar Objects is enabled, Non-Stellar objects from the Guide Star Catalogues, are then displayed as Red-Crosses on STAR Atlas: PRO's charts. In this way you can immediately identify stars and non-stars from each other.

The size of the Red-Cross Symbols are proportional to the object´┐Żs Magnitude, so a larger red-cross represents a brighter Magnitude.


1. Start STAR Atlas: PRO
2. Click [Locate] and click on [Popular] (top centre) then [Messier] and add 31 to the box [Object Designation] (top left).
3. Now click [Find] and then [Map]
4. Click [Field of View] and click the selector box next to the 2-Degrees option (thereby setting the chart to a 2-degree Field of View).
5. Look at the chart and you will see that there are many stars appearing.
6. Next click the [Chart Prefs] button on the main menu.
7. Now enable the [Distinguish Non-Stellar Objects] option by clicking the option box under [Stars] (middle left) so there is a tick-mark present.
8. Click the [Redraw] button and the chart is drawn with Non-Stellar Objects marked with crosses and stars left unchanged as small dots, proportional to their magnitude.

Note: this setting takes effect only when STAR Atlas: PRO displays data from the GSC or the GSC-2.

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