Stars for All Seasons
Like calendar pages strewn across an untidy desk, the stars of summer and even spring linger after sunset, with their autumn and winter counterparts commanding the heavens before dawn.
The sun sets before 6:40, with full darkness following little more than an hour later. Arcturus, the brightest early-evening star and fourth-brightest of all, appears in the sun’s wake due west. The main star of Boötes, the herdsman, Arcturus is the celestial spring sentinel. It sets around 9pm, and as it nears the horizon, it can sparkle wildly as its light is buffeted by our atmosphere.
Far below Arcturus, the red-giant Antares hugs the southeast horizon at sunset. The heart of Scorpius, the scorpion, this constellation is diametrically opposed to Orion, the great hunter of winter. The appearance of the scorpion’s tail heralds the coming of spring, and Antares, the 15th brightest star, glares high in the south throughout summer.
The Summer Triangle is directly overhead at sunset, marked from brightest by Vega, Altair and Deneb. The main star of Lyra the lyre, Vega is the fifth-brightest star, Altair. The eye of the eagle Aquilla, is the 12th. And Deneb, while 19th-brightest, is easy to spot as either the tail of Cygnus the swan or the head of the Northern Cross.
By midnight the whole sky-scape is changed. The Triangle still clings to the western horizon, but now the autumn stars of an ancient feuding royal family shines directly overhead. Cepheus the king, his wife and queen, Cassiopeia, and their daughter Andromeda. Amid the fray, the hero Perseus and his winged mount Pegasus fly to her rescue. Below to the south shines Fomalhaut, 18th brightest and the so-called lonely star amid the constellation Piscis Austrinus.
And there, striding above the east horizon is the familiar hourglass shape of Orion, tracking the great winter bull Taurus, marked by its red eye Aldebaran.