Taurus

A bull with a glowing eye

Taurus, the Bull, is a zodiac constellation of the winter sky. Only the front half of the animal is shown: a head with long horns and two front legs, as if the bull were charging toward Orion the hunter.

Taurus is one of the oldest recognized constellations. A bull in this region appears in Mesopotamian records thousands of years old, and some researchers suggest that the Pleiades may even appear in the Lascaux cave paintings in France, though that idea is debated.

The Sun passes in front of Taurus from about mid-May to late June, so the constellation is lost in the evening twilight in late spring.

How to find it

Find Orion first, with its three belt stars in a short, straight row. Follow the belt up and to the right (west) about two fists, and you land on the orange star Aldebaran.

Aldebaran sits at one end of a small V of stars, the bull's face. Continue the same line about one more fist and you reach a tight little group of stars that looks like a tiny dipper. This is the Pleiades.

The two long horns stretch up and to the left from the V, ending at Elnath and Zeta Tauri. Elnath also forms one corner of the Winter Hexagon and touches the star pattern of Auriga.

The main stars and their names

Aldebaran (Alpha Tauri) is an orange giant star, much larger than the Sun, about 65 light-years away. Its brightness changes slightly around magnitude 0.85. The name is Arabic for 'the follower', because it rises after the Pleiades and seems to chase them across the sky.

Aldebaran is not a member of the Hyades. It only lies in front of them, at less than half their distance. This is a good example of stars that look close but are not.

Elnath (Beta Tauri), magnitude about 1.65, marks the tip of the northern horn; its name means 'the butting one'. Alcyone, magnitude about 2.9, is the brightest star of the Pleiades, and many of the cluster's stars carry the names of the Seven Sisters and their parents, Atlas and Pleione.

Deep-sky objects for binoculars and small telescopes

The Pleiades (M45) is a young star cluster about 444 light-years away. Most people see six or seven stars with the naked eye, but binoculars reveal dozens of blue-white stars in one view. Long-exposure photographs show blue haze around them; this is a dust cloud the cluster is passing through, not leftover material from its birth.

The Hyades, about 150 light-years away, is the closest star cluster of its kind to Earth. It is too large for most telescopes, so binoculars or the naked eye are the best tools. Its stars are much older than those of the Pleiades.

The Crab Nebula (M1) lies just above Zeta Tauri, the southern horn tip. It is the remains of a star whose explosion was recorded by Chinese astronomers in 1054, bright enough to see in daylight for weeks. In a small telescope it is a faint oval glow, about 6,500 light-years away, with a fast-spinning neutron star at its center.

NGC 1647, a loose open cluster northeast of Aldebaran, is an easy second binocular target after the Pleiades.

Mythology

In the ancient Mesopotamian epic of Gilgamesh, the gods send the Bull of Heaven to punish the hero, and many writers link that bull with this constellation.

In Greek myth, Zeus turned himself into a beautiful white bull to win the Phoenician princess Europa. When she climbed on his back, he swam across the sea with her to Crete. The continent of Europe takes its name from her.

The Pleiades have stories in almost every culture. The Greeks saw seven sisters chased by Orion. In Turkish the cluster is known as Ülker, and in many farming calendars its first dawn rising marked seasons for work. In Turkish the constellation itself is Boğa.

Practical observing tips

From late November to February, Taurus is high in the south during the evening. Start with Aldebaran and the V, then move to the Pleiades with binoculars at low power; the wide field shows the cluster best.

Try a simple eyesight test: count the Pleiades stars without optical aid on a dark night. City observers may see four or five, while experienced observers under very dark skies report more than ten.

The Moon passes through Taurus every month and sometimes covers Aldebaran or the Pleiades. Watching a bright star disappear behind the Moon's edge in a small telescope is a memorable sight; astronomy apps list the dates.