Taurus the Bull: Aldebaran and the Pleiades

Taurus is one of the oldest recognized constellations, with depictions dating back thousands of years. This zodiac constellation dominates the winter sky with two of the most famous star clusters visible to the naked eye, the brilliant orange star Aldebaran, and the remains of an ancient supernova. Explore it in real time with StarGlobe.

How to Find Taurus

The simplest method is to use Orion's Belt as a guide. Follow the three belt stars to the upper right (northwest), and the first bright star you encounter is Aldebaran, the eye of the bull. Aldebaran is distinctly orange and sits within a V-shaped cluster of stars called the Hyades, which forms the bull's face.

Continuing past the Hyades in the same direction brings you to the Pleiades, a compact jewel-like cluster that most people can spot at a glance. Together, Aldebaran, the Hyades, and the Pleiades make Taurus one of the easiest constellations to identify.

Two stars above the V of the Hyades represent the tips of the bull's long horns. The one closer to Gemini is Beta Tauri (Elnath), which is bright enough to see from any location. Taurus appears to be charging toward Orion, with only the front half of the bull depicted in the sky.

Aldebaran: The Eye of the Bull

Aldebaran is an orange giant star shining at magnitude 0.85, making it the 14th brightest star in the sky. Located about 65 light-years from Earth, it appears embedded in the Hyades cluster but is actually a foreground star at less than half the cluster's distance. Aldebaran has exhausted the hydrogen in its core and expanded to about 44 times the Sun's diameter. Its name comes from Arabic and means "the follower," referring to its rising after the Pleiades.

The Pleiades: The Seven Sisters

The Pleiades (M45) is the most famous open cluster in the sky. Under clear dark skies, most people see six or seven stars in a tight grouping, though sharp-eyed observers can count more. Binoculars reveal dozens of blue-white stars, and long-exposure photographs show delicate blue reflection nebulosity surrounding the brightest members.

The cluster is about 440 light-years away and roughly 100 million years old, making its stars relatively young and hot. The brightest members bear the names of the Seven Sisters from Greek mythology: Alcyone, Atlas, Electra, Maia, Merope, Taygeta, and Pleione. The Pleiades have been recognized by virtually every culture on Earth. Japanese car manufacturer Subaru takes its name from the Japanese word for this cluster, and its logo depicts six stars.

The Hyades: Face of the Bull

The Hyades is the nearest open cluster to Earth at about 153 light-years. Its V-shaped pattern forms the distinctive face of Taurus. Unlike the Pleiades, the Hyades is an older cluster at about 625 million years, and its stars are more scattered. The cluster contains several hundred members spread across a large volume of space.

The Hyades is important for calibrating the cosmic distance ladder because its proximity allows accurate distance measurements using parallax. These measurements then help calibrate distance estimates for more remote clusters and galaxies.

The Crab Nebula

M1, the Crab Nebula, lies near the tip of the bull's southern horn. This famous supernova remnant is the debris of a star whose explosion was recorded by Chinese and Japanese astronomers in 1054 CE. The "guest star" was bright enough to be visible in daylight for several weeks.

Today, the Crab Nebula is a small, faint oval visible in modest telescopes. At its center lies a rapidly spinning neutron star (pulsar) that rotates 30 times per second, powering the nebula's continued glow. The Crab Nebula was the first object cataloged by Charles Messier, inspiring his famous list of objects that might be confused with comets.

Mythology and Cultural Significance

In Greek mythology, Taurus is commonly identified as the white bull form taken by Zeus to carry off Europa, the Phoenician princess. The constellation shows only the front half of the bull because the hindquarters are submerged as the bull swims across the sea.

Taurus may be one of the oldest identified constellations. Cave paintings at Lascaux in France, dating to roughly 17,000 years ago, appear to depict the Pleiades and Hyades, though this interpretation is debated. Ancient Mesopotamian cultures recognized the bull pattern at least 4,000 years ago. In many traditions, the rising of the Pleiades marked the start of the agricultural season, and their setting signaled its end.

Best Time to Observe

Taurus is best observed from November through February for Northern Hemisphere observers. The constellation reaches its highest point during January evenings. The Pleiades are visible from September through March. From the Southern Hemisphere, Taurus appears in the northern sky during the same months, though lower on the horizon.

Neighboring Constellations

Orion stands to the southeast, appearing to face the charging bull. Gemini lies to the east, Aries to the west, and Perseus to the north. Auriga with Capella borders Taurus at the northern horn tip. Open StarGlobe to see how these winter constellations connect.

Quick Facts

Taurus covers 797 square degrees, ranking 17th in size. It contains two Messier objects (M1 and M45), and Aldebaran shines at magnitude 0.85. The constellation's right ascension ranges from about 3h 23m to 5h 53m, and its declination spans from about -1 to +31 degrees. The ecliptic runs through Taurus, so planets regularly visit this constellation.