1 The official definition is an area of the sky with defined boundaries, all stars and any other objects within that boundary are considered part of the constellation. 2  There are 88 official constellations which are recognized by the International Astronomical Union.irst find the famous Big Dipper, which is part of the constellation Ursa Major and visible all year in the Northern hemisphere, draw an imaginary line through the outer two stars of the Big Dipperâs bowl and you will come to Polaris, which is the brightest star in the constellation of Ursa Minor.