The Summer Triangle returns to the night sky

The constellations shown on modern star atlases are all officially approved by the International Astronomical Union, but while constellations are official, asterisms are not. An asterism is often defined as a noteworthy or striking pattern of stars within a constellation, but that is not always the case. The larger asterisms — ones like the Big Dipper in Ursa Major and the Great Square of Pegasus — are often better known than their host constellations.