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Magnitude

Magnitude is used to specify the brightest and dimmest objects, inclusively, to be included in the report. The dimmest magnitude varies by catalog; a range of values for the selected catalog(s) is displayed if available. In the case of comets and asteroids, the magnitude range is generous.

You must uncheck Ignore to enter values into the Brightest or Dimmest boxes. If 0 is entered for Brightest, the search result includes all magnitudes brighter than Dimmest. If 0 is entered for Dimmest, the search result includes all magnitudes dimmer than Brightest. For example, if you want to search for objects brighter than magnitude 12, you would enter 12 in Dimmest and leave 0 in Brightest. If 0 is entered for both, or if Ignore is checked, all magnitudes are included in the report. If a magnitude is entered that is too dim for the selected catalog, it is changed to the dimmest magnitude for the selected catalog(s).

If the magnitude for an object is missing, it is left blank in the report. If you specify a range of magnitudes for the search, by default, all objects with missing magnitude values are excluded. To include these objects in the report, check Include missing magnitudes.

For Double and Variable Stars

Mag. Difference is used to specify the difference in magnitudes for components of double stars or the brightest and dimmest magnitudes of variable stars.

You must uncheck Ignore to enter values into the Lowest or Highest boxes. If 0 is entered for Lowest, the search result includes all magnitude differences larger than Lowest. If 0 is entered for Highest, the search result includes all magnitude differences smaller than Largest. For example, if you want to search for objects with magnitude difference of 1 or less, you would enter 1 in Highest and leave 0 in Lowest. If 0 is entered for both, or if Ignore is checked, all magnitude differences are included in the report. If a magnitude difference is entered that is too large for the selected catalog, it is changed to the highest magnitude difference for the selected catalog(s).

If the magnitude difference for an object is missing, it is left blank in the report. If you specify a range of magnitude differences for the search, by default, all objects with missing magnitude differences are excluded. To include these objects in the report, check Include missing differences.

What about?

The Magnitude tab is disabled for catalogs that do not contain magnitude data.

Magnitude data may be omitted in the orbital elements of a comet or asteroid.

Magnitude Diff is present only for variable and double star catalogs. Surprisingly, in the case of double stars there are primary components that are dimmer than secondary components, and in the case of variable stars there are brightest magnitudes that are dimmer than dimmest magnitudes. Thus, Mag.Difference is the absolute value of the difference in magnitudes.