Crux, Musca, and Circinus - Downloadable article
Three of the sky's smallest constellations hold a large assortment of southern Milky Way delights.
March 3, 2009
|This downloadable article is from an Astronomy magazine 45-article series called "Celestial Portraits." The collection highlights all 88 constellations in the sky and explains how to observe each constellation's deep-sky targets. The articles feature star charts, stunning pictures, and constellation mythology. We've put together 11 digital packages. Each one contains four Celestial Portraits articles for you to purchase and download.|
"Crux, Musca, and Circinus" is one of four articles included in Celestial Portraits Package 10.
The most southerly stretch of the Milky Way is one of its most interesting. Looking 60° away from the galactic center, we find scores of nearby double stars, clusters, and nebulae crowded into a small area. In the deep south reside Crux, Musca, and Circinus, three of the sky's smallest constellations. While they occupy less than one percent of the celestial sphere, they are far from insignificant to deep-sky observers.
The smallest of the 88 constellations is, paradoxically, one of the most obvious. Crux, the Southern Cross, is so striking in southern skies that it has earned a position of distinction on the flags of Australia and New Zealand. The five stars of Crux are unassociated except for Beta (β) and Delta (δ) Crucis at the east and west ends of the cross, which are separated by only 30 light-years. Three of its stars are brighter than 2nd magnitude and grouped in an area just 6° across. As if all these bright stars in such a small area weren't enough, the Milky Way's most prominent dark nebula resides in Crux. The Coalsack is a stark, starless area 4° across. Only one 5th-magnitude star shines in an otherwise empty region. To read the complete article, purchase and download Celestial Portraits Package 10.
|Deep-sky objects in Crux, Musca, and Circinus|
Lambda (λ) Muscae, NGC 4052, NGC 4071, NGC 4103, NGC 4349, NGC 4372, Alpha (α) Crucis, Gamma (γ) Crucis, Beta (β) Muscae, Coalsack, NGC 4755, NGC 4815, NGC 4833, NGC 5189, MyCn 18, NGC 5315, Circinus Galaxy, NGC 5823