Part 4 - There's more to see!
Published online by Cambridge University Press: 05 August 2012
Summary
Circumpolar constellations
If an observer is south of latitude 35 degrees south, certain constellations may always be seen above the southern horizon circling the South Celestial Pole (SCP). The circumpolar constellations include Octans, Chamaeleon, most of Carina, Crux, part of Centaurus, Apus, part of Indus, Musca, Circinus, most of Ara, Pavo, Volans, Tucana, Achernar of Eridanus, Horologium, Reticulum, part of Dorado and Pictor, Mensa, part of Vela, Triangulum Australe, Hydrus, as well as the Large and Small Clouds of Magellan.
The illusion of these constellations rotating around the SCP is due to Earth's rotation around its own axis. If a line were drawn from the south pole through the center of the earth through the north pole and extended to the celestial sphere it would end approximately 0.8 degrees from Polaris in the north and 13 degrees from Star 2 of the constellation Hydrus in the south.
Test of vision
Although there are 200 billion stars like our Sun in our galaxy, we can only see about 2500 of them at one time above the horizon under ideal conditions.
Color test
Stars vary in color. These colors depend on a star's temperature (just as the color of a flame depends on its temperature). The coolest stars are red, the hottest blue. If you look closely, you can see some of these colors for the brightest stars. Try looking at some of those listed below.
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- Information
- A Walk through the Southern SkyA Guide to Stars and Constellations and their Legends, pp. 99 - 109Publisher: Cambridge University PressPrint publication year: 2007