Magnitude Charts for the Constellation Crux at 40N
Compare the view of your nighttime sky to the Magnitude Charts below. This will determine the magnitude of the faintest stars that you can see at your location. For printouts to use during your observation, you can use the magnitude charts included in the Activity Guides. For practice, try the Observation Practice quiz! (requires Flash)
Can you find Crux?
The constellation Crux (also known as the asterism of the Southern Cross) is easily visible from the southern hemisphere at practically any time of year. For locations south of 34°S, Crux is circumpolar and thus always visible in the night sky. It is also visible near the horizon from tropical latitudes of the northern hemisphere for a few hours every night during the northern winter and spring.
Crux is bordered by the constellations Centaurus (the Centaur), which surrounds it on three sides, and Musca (the Fly). Centaurus is one of the brightest and largest constellations in the southern sky. The two brightest stars in Centaurus, Alpha and Beta Centauri, are often referred to as the “Southern Pointers” or just “The Pointers”, allowing people to easily find the constellation of Crux. (Alpha Centauri is also the 4th brightest star in the night sky.)
Crux is sometimes confused with the nearby False Cross by stargazers. Crux is somewhat kite-shaped, and it has a fifth star (α Crucis). The False Cross is also diamond-shaped, somewhat dimmer on average, does not have a fifth star and lacks the two prominent Pointer stars.
Practice Finding Crux.
(Images modified from charts provided by Jan Hollan, of the Global Change Research Institute of the Academy of Sciences of the Czech Republic)