Calculating Distance
Between Alien Suns

Viewing Cube showing several stars near 61 Ursae Majoris (61 UMa).

Select a Starting Point

First, you need to select your starting point for calculating a distance. Merely point and click the desired star. In this example, we have chosen 61 Ursae Majoris (61 UMa). Nearby are an unusually high number of mid-dwarfs very close by.

Sometimes it is helpful to click on the "Center On" button (see below) and to reduce the scale of the Viewing Cube to minimize the clutter of stars and to make it easier to find that for which you are looking. Then you merely click on the "Calc Distance" button, then select the star to which you want to calculate. This second star is your "distance target."

The magenta (pink) marker surrounds the "distance target" star. Viewing Cube set to 8 parsec scale.

Select a Target Star

After clicking the "Calc Distance" button, you merely select the other star in the distance calculation. This is shown in the Viewing Cube by a magenta (hot pink) marker.

The "Calc Distance" button now becomes a "Done" button, and below it, the distance in either parsecs or light years. Switch between the two units by selecting or deselecting View, Light Years from the main menu, or by using CTRL-Y to toggle between the two.

In our example, we find that the target star (Groombridge 1830) is far closer to 61 UMa than Alpha Centauri is to Sol (our sun) and Earth. But astronomical science tells us that Groombridge 1830 is one of the galactic halo stars—an underluminous sub-dwarf (G8 VI). So, the two stars are not part of a family, but merely a serendipitous pair which will soon pass each other. The luminosity class (VI) frequently gives this away.

Viewing Cube scale set at 16 parsecs. More stars visible, including several know to have planets.

More Calculating
by Point-and-Click

This view shows the Viewing Cube scale expanded to 16 parsecs (from 8 pc shown earlier). Natually, this includes more stars even though we've omitted all types but mid-dwarfs and hot dwarfs. Here we find the distance between 61 UMa and the closest system known to have planets, 70 Virginis (70 Vir).