In the Sky This Month

To the people of Polynesia, the stars of Cassiopeia and Andromeda represented a dolphin, called Kwu. Cassiopeia formed its tail, while the brightest stars of Andromeda formed its fins. Andromeda’s fainter stars outlined the dolphin’s body.

Several stellar time bombs shine in summer’s evening skies. Among the brightest are Antares, the heart of Scorpius, which is low in the southwest at nightfall, and Deneb, the tail of the swan, in the east-northeast. Each star will blow itself apart as a supernova.

Venus, the “morning star,” is passing by a celestial beehive. M44, also known as the beehive star cluster, stands close to the lower left of the Moon at first light tomorrow. Binoculars will reveal many of its individual stars, like a swarm of celestial bees.

The Moon is in beautiful view tonight. It’s just past first quarter, so sunlight illuminates more than half of its disk. The planet Saturn is close to the lower left of the Moon at nightfall, with the star Antares farther to the lower right of the Moon.

A tiny arrow flies high across the sky on summer nights. Sagitta is in the east as night falls, and arcs high overhead later on. Under dark skies, you can just make out the arrow, not far to the upper left of Altair, the bright southern point of the Summer Triangle.

A fetching star cluster comes into view on summer evenings. Messier 11 is more than 6,000 light-years away, in Scutum, the shield. Its brightest stars make the shape of the letter V, resembling a flight of ducks, so M11 is also known as the Wild Duck cluster.

If you look south shortly after sunset tonight, you’ll see eight moderately bright stars arranged in the shape of a teapot. That’s the constellation Sagittarius. It’s also where the center of our galaxy is, about 27,000 light-years away.

Jupiter teams up with the Moon this evening. The solar system’s largest planet looks like a brilliant star close to the lower right of the crescent Moon. The true star Spica stands below the Moon.

The Moon stages another beautiful encounter early this evening. It lines up with the planet Jupiter and the star Spica, the leading light of the constellation Virgo. Jupiter is by far the brighter of the two, with Spica close to its lower left.

NGC 6946 is both beautiful and busy. It’s a spiral galaxy that we see face-on. Over the last century, astronomers have recorded 10 supernova explosions in the galaxy, with the most recent just three months ago. So NGC 6946 is also called the Fireworks galaxy.