Using Constellations to Find Other Constellations

The stargazer stepped out his front door and into the street, tilting his head up in the night air to get a better view of the winter sky. He quickly picked out the three stars that make up Orion's belt, and from there he could make out the rest of the popular constellation. With confidence he pointed up at Orion, and then pivoted roughly forty five degrees to his left, observing where his finger wound up. There in front of him was the rough shape of the capital letter M, the constellation of Cassiopeia. From here the amateur astronomer continued to use one constellation or star to jump off and find another, and spent a pleasant evening gazing at the stars.

What is a Constellation?

Like many other concepts when it comes to space and mankind's understanding of it, the meaning of the term "constellation" can change based on who is using it. For the most part a constellation is a grouping of stars that, when seen from the surface of the earth, represents a pattern that is meaningful to the observer. While constellations names and shapes vary over the centuries and based on culture, the International Astronomical Union (IAU) has a list of 88 "official" constellations that are used in most star and sky charts in modern times.

There is plenty of advice that can be handed out to beginning astronomers; get away from city lights (to avoid "night pollution") to see the stars, pay attention to weather forecasts (one can't see the stars through clouds), get a decent pair of field glasses to start off, and print out or buy a sky chart appropriate for the time of year. One bit that isn't on many official guides but which can be very useful is to use one constellation to find another.

Use what you Have

To do this a stargazer does not need any additional equipment than what he or she will already take with them into the field, although time spent in a comfy chair with a nice cup of tea can be useful when studying the same sky charts. The key to using constellations to find others is really just a way of approaching the subject. Like landmarks used to travel over new ground a second or third time, using known constellations will breed familiarity with the night sky, and before long the amateur astronomer is becoming a bit of a pro at locating as many of the 88 star pictures as can be seen from his or her part of the world.

Final Thoughts

In the above example Orion was used - and specifically Orion's Belt. The slanted, straight line of three bright stars is a favourite of many star watchers, even those that only look up into the night sky a couple of times a year. It is easy to see and easy to recognize, and from there a slight glance up and down can pick out the rest of the Hunter. Facing the belt straight on and then slowly turning to the left a viewer will soon be rewarded with the M (or W depending on where you are viewing it) of Cassiopeia. A viewer who does this a half dozen times will soon be able to find Cassiopeia just as quickly as Orion, and use this new constellation to find Ursa Major, Taurus and Gemini.