NGC 6188 is a combination emission/reflection nebula. Even a 4-inch scope will reveal a faint haze measuring 20' by 12' that interacts with open cluster NGC 6193. Larger scopes will reveal a dark region separating the eastern and western halves. Credit: Gerald Rhemann
The constellation ARA (pronounced AIR-uh) the Altar was one of the “original” constellations of the Greeks. It appeared in Phaenomena, a 3rd-century-b.c. work by the Greek poet Aratus. He based it on a work written a century earlier by Eudoxus of Cnidus. The constellation’s position is easy to locate directly beneath the tail of Scorpius. Making an altar out of the stars is more difficult.
Ara is visible May through July in the Northern Hemisphere, the time Scorpius hangs directly in the south. Its center lies at right ascension 17h18m and declination –56°30′.
