April Tonight’s Sky Constellations
Clear April nights are filled with starry creatures.
Face north. Overhead, you will find Ursa Major, the Great Bear.
The Big Dipper, which forms part of the bear, is one of the most familiar star patterns in the sky.
In the middle of the handle lie Mizar and Alcor, a double star discernable with the naked eye.
A telescope shows Mizar and Alcor as a diamond-white pair of stars.
In fact, this is a six-star system: Alcor is itself a binary, while Mizar is actually two sets of binaries—a quadruple star.
During the spring, our view is away from the cloudy plane of the Milky Way, and the clearer view reveals other galaxies.
Near the end of the Big Dipper’s handle lies the Pinwheel Galaxy, also known as M101.
A ground-based telescope reveals its spiral shape.
With the eye of the Hubble Space Telescope, we can see individual stars that make up this spiral galaxy.
The Pinwheel Galaxy is similar in both size and shape to our own Milky Way galaxy.
This composite image shows infrared and X-ray, as well as visible wavelengths of light.
X-ray and infrared light allow us to see the galactic gas that is otherwise invisible to human eyes.
Bright X-ray points mark black holes and neutron stars emitting energy as they consume nearby companions.
Beyond the Big Dipper’s bowl lies a pair of galaxies: M81 and M82.
The two galaxies are relatively nearby, just 12 million light-years away—and very close to each other— just 150,000 light-years apart.
South of the Great Bear roams another great beast: Leo the Lion.
Leo’s bright heart is marked by the star Regulus—a system of four stars—two double stars circling each other.
Within Leo’s stomach lie a number of galaxies.
Two of them—M95 and M96—are large spirals.
An infrared view of M95 shows an orderly galaxy seen face-on.
A visible light view of M96 shows an asymmetric galaxy, probably gravitationally disrupted by encounters with its neighbors.
Look skyward for the glittering galaxies and fierce beasts of April.
Celestial wonders await you in tonight’s sky.
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