Find the spring constellations

A NOTE ABOUT LATITUDE: These sky charts assume an observer at 40 degrees north latitude; much of the world's population lives within 20 degrees or so of 40 degrees north, so it is a useful latitude assumption.  However, if you are north of this latitude, the stars will all appear shifted towards the south; if you reside south of this latitude, the stars will appear shifted to the north. 

In the Northern Hemisphere during the spring, the constellation Ursa Major tends to be high overhead not long after it gets dark. Within this constellation are seven stars of 2-nd magnitude, which are visible from all but the very worst light polluted areas. These seven stars are are an “asterism” - or shape that is recognizable but not a true constellation - known as the “Big Dipper” in North America, and “The Plough” in the U.K. From this asterism, we can find quite a few other constellations and bright stars. Let's begin with the “bowl” of the Dipper. First, watch this video (COMING SOON) on how to measure distance in the sky. And if you are unsure about the differences in magnitude, check out this video (COMING SOON) first as well.

The two end stars of the bowl are Merak and Dubhe. If we draw a line from Merak through Dubhe, and continue on slightly more than 25 degrees, we arrive at another 2-nd magnitude star: Polaris, also known as the North star. As the Earth spins on it's axis, Polaris hardly moves, as it is less than one degree from the north celestial pole, the spot in the sky around which the stars appear to rotate. Polaris is the end of the tail of “Ursa Minor” - the little bear, though many in North America refer to this as the “Little Dipper.” The “handle” or “tail” of this shape may be hard to see, but if you know that these stars curve back towards the Big Dipper, you should be able to find a slightly orange looking star of similar magnitude, about 15 degrees away from Polaris. This star is Kocab, and forms the end “lip” of the Little Dipper's “bowl.”

But back to the Big Dipper, this time, the arcing handle of the dipper shape. One easily remembered mnemonic is “Arc to Arcturus, speed on to Spica.” So if we track that curving line of three handle stars, then continue on 30 degrees, we find a brighter first magnitude star there, and that is Arcturus, the brightest star in Bootes, the Herdsman. Bootes forms an “ice cream cone” shape in the sky, though many of its stars are much dimmer than Arcturus. But don't stop there yet – we still need to “speed on to Spica!” Continuing our “arc” another 30 degrees past Arcturus, you will arrive at another bright star about the same magnitude as Arcturus, but this bluish looking star is Spica. This star anchors the quite dim constellation of Virgo, but there are many galaxies nearby which are great to target, so knowing Spica's location is helpful. Also, Spica is very nearly on the line of the ecliptic, so the planets will pass by this star from time to time as well.

Once more, we will head back to the Big Dipper. The two inner stars of the “Bowl” can now point us in another direction. Look for 3.3 magnitude Megrez and 2.4 magnitude Phad, and draw a long line across the sky, measuring 45 degrees until you reach the bright star Regulus, in Leo the Lion. Leo has a “sickle” shaped head area, and towards it's tail is the “Virgo Galaxy Cluster” that we talked about earlier. Regulus is also near the line of the ecliptic.

The last hop from the Big Dipper is straight across the top of the bowl: Go from Megrez through Dubhe, then draw a line 50 degrees across the sky, and you can't miss Capella, the brightest star in the pentagon shaped Auriga the Charioteer. Turning just slightly south of Capella and Auriga is where the Gemini the twins reside, and Pollux and Castor should be visible, just slightly less bright than Capella is.  To the east, there are summer constellations and stars rising that may be visible, such as Ophiuchus, Hercules, and Vega, among others.  Click ahead to see the Summer Constellations page, as these constellations will be visible later at night during the spring months.

That's a great primer course on how to find your way around the spring sky – give it a try on a clear night, and if you want to see more, look for the star charts at this site for deep sky objects you may be able to spot in the spring sky as well.