Constellations Are Groupings of Stars on the Sky, Often Represented As Connect-The-Dots

CONSTELLATIONS

 Constellations are groupings of stars on the sky, often represented as “connect-the-dots” patterns in star charts.  The names of most constellations and stars were defined by early astronomers from several societies, especially Greek, Roman, and Arabic astronomers.  Constellations do NOT change appearance on human timescales – the patterns remain the same over thousands of years. The constellations visible to early human civilizations are the same as visible today.  There are 88 official named constellations covering all areas of the sky. Every place in the sky is located within a constellation. Maps of the constellations are termed star atlases.  Constellations are two-dimensional patterns on the sky, but they are not real objects in space. The stars within a constellation are not physically grouped together, because these stars are all located at different distances from Earth.  Constellations have both ancient and modern significance.  Ancient cultures wove fascinating mythologies around the stars and constellations.  Today, the names of the constellations are used to identify the locations of celestial objects.  The brightest stars in each constellation are labeled using the Greek alphabet: , , , , etc. For example the brightest star in the sky, Sirius, is also known as  Canis Majoris.  Certain stars and constellations are identified with specific seasons of the year, because those constellations are visible from the northern hemisphere in the southern sky during the evening hours. Examples:  Winter: Orion, Taurus, Canis Major, Gemini, Betelgeuse, Sirius  Spring: Leo, Bootes, Virgo, Arcturus  Summer: The Summer Triangle, Cygnus, Scorpius, Sagittarius  Fall: Pegasus, Andromeda, Persues  Over much longer times (millions of years), the patterns of constellations will change as the solar system moves through the Galaxy, along with other stars.