ConstellationBasics-500Our Constellation Basics webinar gives vital background information about the major winter constellations. But just as you can't learn to ride a bicycle by reading a book, you can't learn the constellations from the comfort of your own living room. You need to go outside and look -- with the aid of an interactive resource.

The oldest tool for learning the constellations, and still one of the most effective, is a planisphere, also called a star wheel. It includes a chart of all the constellations ever visible from your location plus a sliding window that shows you which ones are visible at any given date and time. Senior editor Alan MacRober explains how to use a planisphere in this video. Sky & Telescope sells a full selection of planispheres, including a unique model that omits the faintest stars, showing only the constellations that are obvious from a typical suburb.

Versatile as they are, planispheres have two drawbacks. Because they include all the stars visible at every season, the ones that happen to be visible at any moment end up in a fairly small window, and they're also somewhat distorted. And they cannot show the positions of the planets, which are constantly changing.

For those reasons, it's often convenient to have all-sky charts tailored for the specific month when you're using them. Every issue of Sky & Telescope includes a 2-page all-sky chart, together with a calendar showing special events for the month in question. SkyWatch, our annual magazine, includes single-page charts for each month bundled together in one convenient package. Or you can download a printable 2-page chart for the current month at

Electronic devices are more versatile still, because they can be customized not only according to the date and time but also for specific locations. And you can zoom in or out. Sky & Telescope's Interactive Sky Chart is extremely popular for use on computers. To achieve more flexibility (at the cost of more effort), you can download and install a planetarium program, including the popular freeware Stellarium.

Smart phones and tablets are much more convenient than computers for outdoor use. Sky & Telescope's free SkyWeek app lists interesting celestial events for every day of the current week, and if you press the View button, it brings up a sky chart showing that event. You can then pan, zoom, and change the time to find all of the constellations and planets that are visible that night. The underlying engine is a stripped-down version of the hugely popular SkySafari app. Even the cheapest version of this app shows the sky in great detail. You can also point your device anywhere in the sky, and Sky Safari will show a labeled chart of whatever you're looking at -- a tremendously useful feature.

For additional background information, see our complete list of constellation names and abbreviations, which includes an audio guide to pronunciation. Probably the best succint online resource for constellation history is Ian Ridpath's wonderful book Star Tales, which is also available in print.


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