Constellations
Several stars in our universe are notable on their own merit. Sol, our sun, is indeed a star, even though we tend think of stars as little orbs of light that dot our skies and exist millions of miles away. Polaris, the North Star, an important reference point in the sky for navigators in the pre-GPS era, is also given its own place on the mantle of our collective recognition of stars. Other stars visible in our night skies, meanwhile, are better understood in relation to one another and are identifiable to even young children based on their shape. A certain grouping of stars that has been identified for the spatial relationship among stars or has otherwise been named for its shape is known as an asterism, or more commonly, a constellation. Constellations are one of the phenomena of astronomy that make it so endearing to its students. The study of astrology and reading the constellations, while dubious as a legitimate science and despite being a source of revenue for some, is often a fun pastime for people. Going back in time, some groups even attached a special meaning or power to these constellation groups, and even today, some people are fervent believers in the predictive abilities of the positions of stars and the movement of the planets. Seeing as there are so many views on the subject of constellations, one should take the care to parse out what may or may not be true about them. Some things to note:
1. Technically, an asterism and a constellation are separate but related concepts. Asterisms may be any groups of stars that would seem to be arranged in recognizable pattern, but constellations, according to the astronomical community, encompass both the stars and all celestial bodies within the defined boundaries. In this conception, a constellation is not so much an object as a destination or region mapped out in the skies. Eighty-eight constellations are officially recognized by the International Astronomical Union.
2. Not every grouping of stars qualifies as a separate constellation. The Big Dipper is one of the most recognizable stellar groups to American audiences, but it is not recognized among the said list of IAU constellations because it is, in fact, part of one; the Big Dipper is considered to be part of the larger Ursa Major. Similarly, “Orion’s belt” may be conceived by some as a constellatory bloc as it is the most recognizable feature, but that honor really belongs to Orion as a whole.
3. A constellation may look as if it contains stars that are very near in relation to one another, but this may be the limitations of perspective. Stars in an asterism may look to be neighbors, but frequently, they are really light years (a measure of distance) apart. The nature of perspective also makes for differing views of constellations based on location of residence; some structures might go unnoticed to observers in different hemispheres, and besides, the axes of astral projections become skewed over time.