In the Sky This Month

Aldebaran, the brightest star of Taurus, will stand below the Moon at first light tomorrow. Aldebaran represents the bull’s eye, and stands at one tip of a V-shaped pattern of stars that outlines his face.

The Pleiades star cluster, the sparkly shoulder of Taurus, the bull, rises in the northeast about two hours before the Sun. Its brightest stars form a tiny dipper. Tomorrow, it will stand to the upper left of the crescent Moon.

Alphecca, the crown jewel of the northern celestial crown, stands almost straight overhead a couple of hours after sunset. It consists of two stars, although they are so close to each other that their light merges to form a single pinpoint.

Three bright stars in this evening’s sky have a lot in common. Deneb, Antares, and Spica are among the biggest, brightest, and heaviest stars in the galaxy, and each will end its life with a titanic explosion known as a supernova.

A small, faint “shield” of stars climbs high across the southern sky tonight. The constellation Scutum represents the coat of arms on the shield of John Sobieski, a 17th-century king of Poland and one of the country’s great heroes.

The Moon will be at last-quarter before dawn tomorrow, so sunlight will illuminate half of the lunar hemisphere that faces Earth. The Moon is three-fourths of the way through its monthly cycle of phases.

The Milky Way is beginning its journey into summer’s evening skies. It arcs low across the east not long after nightfall. It’s anchored by teapot-shaped Sagittarius in the south, the graceful swan in the east, and W-shaped Cassiopeia in the north.

The Coathanger, a pattern of 10 stars that looks like a coat hanger, is in the faint constellation Vulpecula, the fox. It lines up between the the bright star Altair, which is low in the east at nightfall, and brighter Vega, far to its upper left.

While the northern hemisphere enjoys the beginning of summer today, the southern hemisphere is heading into winter. The June solstice is the longest day of the year north of the equator, but the shortest day south of it.

Summer arrives in the northern hemisphere tomorrow morning. At that moment, known as the summer solstice, the Sun will stand farthest north for the entire year. It marks the beginning of summer in the northern hemisphere.