Just beneath the Coal Sack is an extremely bright star. If this star were in the northern sky, only Sirius would shine brighter. But being the third-brightest star in the whole sky isn't this star's only claim to fame. You're looking at the Alpha Centauri system—our nearest stellar neighbor, only 4.3 light-years from the sun.
Alpha Centauri resides at the foot of the Centaur in the constellation of Centaurus. To find it, imagine a line running from Delta Crucis through Becrux, the stars forming the short arm of the Southern Cross, and continue the line south for about 14 degrees until you reach a bright star. Don't be confused by a bright but fainter star near by.
Using the "hand system" of measuring distances in the sky, stretch your arm out to its full full length and spread your fingers.
At that distance, the gap from the tip of your index finger to the tip of your little finger covers about 15 degrees.
Alpha Centauri (or Rigel Kentaurus, as it is also known) is actually a system of three gravitationally bound stars. The two main stars are Alpha Centauri A and Alpha Centauri B. The tiniest star in the system is a red dwarf called Proxima Centauri—the closest of the three stars to the sun.