Ara is a small constellation in the southern hemisphere. The name derives from the Latin word for "altar." The constellation was charted by Ptolemy in the 2nd century. In Greek mythology, Ara is usually identified with the altar upon which the gods swore their allegiance to Zeus before going to battle with the Titans. In other tales, Ara represents the altar on which the Arcadian king Lycaon sacrificed his grandson and served him as dish to Zeus, after which the angry god slaughtered Lycaon's 50 sons and turned him into a wolf (Lupus). Ancient Greek navigators believed that, if the Ara constellation was the only one visible in a cloudy sky, this was a sign of storm at sea.
Ara occupies an area of 237 square degrees and contains four stars with known planets. It can be seen at latitudes between +25° and -90° and is best visible at 9 p.m. during the month of July.
The brightest star in the Ara constellation is 
beta Arae, an orange K-type giant, possibly a supergiant, 603 light-years distant from Earth. Its luminosity is about 4600 times that of our Sun.
alpha Arae, only one percent fainter than beta, is a spectroscopic binary, a variable Be star, that rotates very quickly and is surrounded by a dense equatorial disk of ejected material. The Chinese call the star Tchou or Choo ("pestle").
gamma Arae is a binary star composed of a blue-white B-type supergiant and a white A-type main sequence dwarf.
mu Arae or HD 160691 in the Henry Draper catalogue, is a yellow star with a planetary system believed to contain four planets, three of them similar to Jupiter in size.
Other notable stars in Ara are R Arae, an Algol-type eclipsing binary, 
zeta Arae, an orange K-type giant, 
delta Arae or Tseen Yin ("the Dark Sky"), a B-type main sequence dwarf with a 12-magnitude optical companion, 
theta Arae, a blue-white supergiant, 
lambda Arae, a yellow-white subgiant, 
eta Arae, a binary star with an orange K-type giant for a primary, epsilon Arae, a binary system with 
, an orange K-type giant and 
, a triple star system with a yellow-white dwarf for a primary, and 
sigma Arae, a white A-type main sequence dwarf about 386 light-years distant from Earth.
The Ara constellation also has several notable deep sky objects. NGC 6193 is a large open star cluster near 
alpha Arae, containing about 30 stars. NGC 6208 is another open star cluster that appears as an irregular glow near 
epsilon 1 Arae. NGC 6397 is a bright globular cluster visible even to the naked eye on a clear night.
Ara belongs to the Hercules family of constellations, along with Hercules
, Corona Australis
, Triangulum Australe
Constellations directly bordering Ara are Corona Australis
, Triangulum Australe