In the Sky This Month

The constellations of spring begin to dominate the evening sky this month. Leo, the celestial lion, stands in good view at nightfall and leaps high across the south later on. Virgo follows the lion across the sky, with their brightest stars, Regulus and Spica, respectively, separated by more than 50 degrees — more than five times the width of your fist held at arm’s length.

April 19: Crab Nebula

The Crab Nebula, which is the debris from an exploded star, stands close above the Moon this evening. It is an easy target for small telescopes. Its filaments of gas and dust resemble the outline of a crab.

April 20: Morning Mercury

The planet Mercury just peeks into view in the east at dawn sky over the next few days. It looks like a fairly bright star. It is quite low, though, so you need a clear horizon to see it. The planet stands a little higher as seen from southerly latitudes.

April 21: Lyrid Meteors

The Lyrid meteor shower should be at its best tonight. You need dark skies to see it. Even at its peak, the shower produces no more than a dozen or so meteors per hour. But the Moon is out of the way, so if you have a good viewing spot it’s worth a look.

April 22: Cor Caroli

Cor Caroli, the Heart of Charles, is the brightest star of Canes Venatici, the hunting dogs. It’s to the right of the handle of the Big Dipper as night falls, and wheels above the dipper later on. It consists of two stars in a wide orbit around each other.

April 23: Moon and Regulus

The Moon descends the western sky this evening, with the star Regulus to the left or upper left of the Moon. Regulus is the heart of Leo, the lion, and one of the brightest stars in the night sky.

April 24: More Moon and Regulus

Regulus, the heart of Leo, the lion, stands close to the right of the Moon as darkness falls. The Moon passes the star roughly once per month. Their conjunctions are possible because both lie near the ecliptic, which is the Sun’s path across the sky.

April 25: Corvus

Corvus, the crow, is low in the southeast at nightfall and arcs across the southern sky during the night. Corvus’s brightest stars form a small but distinct box. In mythology, the crow was a servant of the god Apollo.