The False Cross

February 17, 2012

The famous constellation Crux, the Southern Cross, is the jewel of the southern sky and the starting point for most observers who wish to learn the stars of the southern hemisphere. But in their search for Crux, many stargazers are tricked by the “False Cross”, a group of stars in the constellations Carina and Vela that resemble Crux. Here’s how to find the False Cross, and how to tell the difference from the real thing.

The only audio guide to the stars of the southern hemisphere! Grab your binoculars, plug in your iPod, and tour the wonders of the southern stars. Full notes and star maps included for all four seasons. Click here to learn more…

The False Cross lies about 25 degrees west-northwest of the Southern Cross, and about 20 degrees north-northeast of the Large Magellanic Cloud. It’s not a constellation, merely an asterism of four stars: delta Velorum, kappa Velorum, iota Carinae, and epsilon Carinae (Avior).

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The only audio guide to the stars of the southern hemisphere!  Grab your binoculars, plug in your iPod, and tour the exotic wonders of the southern stars.  Full notes and star maps included for all four seasons.  Click here to learn more…

The "False Cross" and the constellation Crux, the Southern Cross, as seen looking south in early March at 9 p.m. local time from 35S latitude (click to enlarge).

The False Cross tends to grab the attention of new stargazers, possibly because it’s a little larger than Crux. (Many are surprised at the small size of Crux when they first see it… the long axis of Crux is just 6 degrees long). But here’s how to tell the difference: the False Cross has more of a diamond-shape, while Crux has more of a true cross (or kite) shape. Crux also has brighter stars, on average, and has two very bright stars alpha and beta Centauri to the southeast. Crux also has a fifth star, epsilon Crucis, between the stars Acrux and delta Crucis.

Grab a pair of binoculars and sweep the region around the False Cross. It is resplendent with fine open star clusters and emission nebulae. The cluster IC 2488 is a snap to find… it’s about halfway between kappa Vel and i Carinae, just east of the line joining the two stars.