The Spring Triangle is a large asterism formed by three bright stars: Arcturus in Boötes, Spica in Virgo and Denebola in Leo. It is especially prominent during spring evenings in the Northern Hemisphere, when its three stars form an easily recognizable landmark in the night sky.
How to Find the Spring Triangle
The easiest way to find the Spring Triangle is to begin with the Big Dipper in Ursa Major. Follow the curve of its handle away from the bowl and continue the same arc until you reach Arcturus, a bright orange star in Boötes. Continue the curve farther south and you will reach Spica, the brightest star in Virgo. From Spica, look toward Leo for Denebola, which marks the Lion’s tail and completes the Spring Triangle.
Don’t expect the three stars to sit close together — the Spring Triangle is enormous, with each side spanning roughly 33° to 35° of sky, or more than three fist-widths held at arm’s length.
Arcturus and Boötes
Arcturus is the fourth-brightest star in the entire night sky — and the brightest in the Spring Triangle — making it an easy, unmistakable starting point for finding Boötes, the Herdsman. From this brilliant orange star, look northward for the constellation’s other main stars forming a large, elongated kite shape, with Arcturus at its pointed lower end. The combination of Arcturus’s brightness and color with the distinctive Kite makes Boötes one of the easiest spring constellations to recognize.
Spica and Virgo
Spica, one of the brightest stars in the night sky, appears blue-white but is actually a close binary that cannot be separated with the naked eye. It provides the easiest starting point for finding Virgo, the Maiden, with most of the constellation’s fainter stars spreading north and west from Spica. Virgo is large and sprawling rather than immediately recognizable, but under reasonably dark skies its main stars can be traced into a loose Y-shaped pattern extending away from the star.
Denebola and Leo
Denebola marks the tail of Leo, the Lion, and is its second-brightest star after Regulus, which is bright enough that some versions use it instead to form a much larger Spring Triangle. From Denebola, look for the small triangle of stars forming the Lion’s hindquarters, then follow its main stars westward across the Lion’s body toward the distinctive Sickle, a backward question-mark pattern forming its head and mane, with bright Regulus at its base.
Constellations Near the Spring Triangle
Once you have found the Spring Triangle and its three constellations, you can use the same bright stars as reference points for identifying a couple of other recognizable constellations nearby.
Coma Berenices
Between Leo and Boötes lies Coma Berenices, Berenice’s Hair, which can be found by looking beyond Denebola and Leo’s tail toward Boötes. The constellation’s most recognizable feature is the Coma Star Cluster (Melotte 111), a large, loose scattering of faint stars spread across several degrees of sky, with its brighter members forming a rough V-shaped pattern.
Corvus
Southwest of Spica lies Corvus, the Crow, which can be found by looking for a compact four-star pattern a short distance beyond Virgo. Its four brightest stars form a distinctive, slightly uneven quadrilateral, and it is this compactness and clean geometric shape, rather than the brightness of its stars, that makes Corvus surprisingly conspicuous against the surrounding sky.