Taurus (space science)

FIELDS OF STUDY: Astronomy; Observational Astronomy

ABSTRACT: The constellation Taurus is a group of stars visible in the Northern and Southern Hemispheres. The main stars take on a shape that people believe looks like a bull. In ancient times, people studied the stars for practical and religious purposes. Today, astronomers still look to the constellations to learn more about science. Taurus contains bright stars, paired stars, and important star clusters called the Hyades and Pleiades. In addition, the Crab Nebula and two meteor showers within the constellation attract the attention of Earth observers.

The Bull Constellation

Taurus is a constellation, a section of the night sky as designated by the International Astronomical Union (IAU). Constellations are star patterns that seem to make a picture in the night sky. People have observed constellation for thousands of years. In ancient times, people be-lieved these star shapes had spiritual importance. They also helped people keep track of the changing seasons. Today, the IAU recognizes eighty-eight official constellations.

Taurus, one of the most famous constellations, looks like a large V shape with a line trailing off the point of the V. The V is meant to represent the “horns” of the bull. Ancient astronomers included Taurus in the zodiac, a circle of twelve constellations through which the sun appears to travel over the course of a year. This path that the sun follows through the zodiac is called the ecliptic.

Modern astronomers locate constellations by measuring their position relative to the celestial equator, the projection of Earth’s equator onto the night sky. Taurus has a declination of approximately +15 degrees and a right ascension of four hours. Declination and right ascension correspond to latitude and longitude on Earth.

Attributes of Taurus

The Taurus constellation can be seen from the Northern and Southern Hemispheres between the latitudes of 90 degrees north (the North Pole) and 65 degrees south. Although it is visible in the night sky from November until March, it is best viewed during January evenings around 9:00 p.m. Taurus is one of the most easily found and visually striking of the constellations.

The most distinctive feature of Taurus is a V-shaped asterism that makes up the bull’s horns and head. Toward the base of the V is the bright red giant star alpha Tauri, better known as Aldebaran, which is more than forty times the size of the sun. Although it is about sixty-five light-years away from Earth, Aldebaran is still about the fourteenth brightest star in the night sky. Astronomers think of it as the eye of the bull, both for its powerful brightness and its blazing, seemingly bloodshot appearance.

At one end of the V is beta Tauri, better known as Elnath, a blue-white star that represents the tip of the bull’s horn. Some of the other named stars that make up the bull’s head and body include gamma Tauri (Hyadum I), epsilon Tauri (Ain), and eta Tauri (Alcyone). Lambda Tauri, in the middle of the bull’s body, is an eclipsing binary star, which means it is actually a pair of stars that revolve around each other. To Earth observers, this motion results in regular eclipses in which one star blocks the light of the other. Theta Tauri, kappa Tauri, sigma Tauri, phi Tauri, and chi Tauri are other examples of double stars.

Taurus also contains several important deep-space objects. One of these is a diffuse nebula, a vast cloud of dust and gases floating in space. This cloud is variously designated as Messier 1 (M1), New General Catalog 1952 (NGC 1952), and Taurus A and is popularly known as the Crab Nebula due to its crab-like shape. It is the remnant of a supernova.

Taurus also contains two major star clusters, the Hyades and the Pleiades. The Hyades cluster, which contains about two hundred stars, helps form the "head" of the bull constellation. The clustered stars appear to encircle Aldebaran, but in fact they about 150 light-years away, compared to Aldebaran’s 65 light-years. The cluster of stars and dust known as Pleiades, sometimes called the Seven Sisters, is located above the body of the bull. As of 2022, astronomers have discovered more than five thousand exoplanets—planets that orbit stars other than our sun. Of those exoplanets, seventy-one have been found in the constellation Taurus.

Mythology

Historians today recognize Taurus as one of the first constellations to be identified. Stories about the constellation date back to the early Bronze Age, and it may have been recognized even earlier than that. Some scientists believe that humans depicted a bull in the stars in cave paintings dating back to distant prehistoric times.

Taurus was also one of the most important constellations. Its position in the zodiac marked the spring equinox to stargazers in ancient Greece and the Middle East. To many cultures, the appearance of the bull represented the beginning of a bright new year and hopes for a productive harvest season.

Cultures around the world developed their own myths and lore about the star pattern. The most detailed myths that have survived to the present day, and those most influential to the modern view of Taurus, originated in ancient Greece. Many ancient Greek myths dealt with bulls, which were considered at the time to be symbols of strength and fertility.

In one myth, the king of the gods, Zeus, fell in love with a beautiful princess named Europa. Zeus appeared before Europa disguised a white bull with golden horns and knelt down. The princess climbed on its back and the bull went racing across the seas to a faraway island, where Zeus finally revealed his true identity.

Another myth involves a bull sent to King Minos of Crete. The king was supposed to sacrifice the animal to the sea god, Poseidon, but neglected to do so. Poseidon was angered by the apparent slight and arranged for Minos’s wife, Pasiphaë, to fall in love with the bull. Pasiphaë then gave birth to the Minotaur, a half-bull, half-human monster that would later be killed by the hero Theseus.

Other Greek myths involve heroes hunting bulls. One of the greatest Greek mythical heroes, Heracles (romanized as Hercules), was tasked with subduing the bull of Crete. Other legends tell of the great hunter Orion stalking bulls for prey. This latter tale is reflected in the constellations, as Taurus and Orion seem to be eye-to-eye, forever locked in combat.

Although the Greek myths are most widely recognized today, many other cultures around the world developed their own interpretations of the star patterns. Early Arabian peoples also imagined a bull in the stars. Some Egyptian astronomers drew a connection to their god Apis, who took the shape of a bull. Other Egyptians instead made a connection to the god Osiris, who had a human form but was usually depicted with a large, two-peaked hat that resembled horns. Chinese astronomers thought of the constellation as a tiger or a bridge in the stars.

Other myths relate to the formations within Taurus. The Greeks had related the stars of the Pleiades cluster to the seven mythical daughters of the Titan Atlas and the nymph Pleione. The Zuni people of New Mexico considered the Pleiades a symbol of seeds. When these "star seeds" appeared in the sky, it was a clear reminder that the time had come to plant crops for the new harvest season.

Studying Taurus Today

Ancient people considered the constellations extremely important. These star patterns offered spiritual meanings as well as a calendar of the changing seasons. Today, most people look to the stars for other reasons. Amateur stargazers enjoy the beautiful marvels of the heavens. Professional astronomers study the constellations to learn more about their various features and gain scientific insights into the workings of the universe.

Taurus is popular with stargazers because some of its most impressive features, such as Aldebaran and the Pleiades, are often visible to the naked eye. Other main parts of the constellation can be seen with binoculars or small telescopes. Experienced stargazers have developed several techniques for quickly locating Taurus in the night sky. One of the most popular is finding Orion’s belt, which will lead the observer’s eye to Aldebaran and the Hyades cluster. From there, observers can locate the rest of the constellation with ease.

Astronomers often look to Taurus to study developments among its stars, clusters, and nebula. In addition, each year many telescopes turn to this constellation in search of meteors. From September through December, the Taurid meteor showers takes place. These showers cover both the Northern and Southern Hemisphere, peaking at different times for each hemisphere. In June and July, daylight meteor showers called the Beta Taurids can send about twenty-five meteors streaking through the sky every hour.

PRINCIPAL TERMS

• celestial equator: the imaginary line in the night sky that follows Earth’s equator, dividing the celestial sphere in half.
• constellation: a group of stars that can be seen in the night sky from Earth and is officially recognized by the International Astronomical Union.
• declination: the north-south position of a celestial body relative to the celestial equator, expressed in degrees of arc.
• International Astronomical Union: the authoritative international organization of astronomers.
• right ascension: the east-west position of a celestial body when viewed from the Earth’s equator, defined in relation to the vernal equinox (one of two points at which the ecliptic intersects the celestial equator) and expressed in hours and minutes.

Bibliography

Kronberg, Christine. "Taurus." The Munich Astro Archive. U Observatory Munich / Leibniz Supercomputing Centre, 21 Mar. 1997. Web. 6 May 2015.

"List of Extrasolar Planets in Taurus." Universe Guide, www.universeguide.com/extrasolar/taurus. 14 June 2022.

McClure, Bruce. "Taurus? Here’s Your Constellation." EarthSky. Earthsky Communications, 5 Jan. 2015. Web. 6 May 2015.

Sessions, Larry, and Deborah Byrd. "Aldebaran Is the Bull’s Fiery Eye." EarthSky. Earthsky Communications, 29 Dec. 2014. Web. 7 May 2015.

"Taurus (the Bull)." Chandra X-Ray Observatory. NASA, 2 Dec. 2013. Web. 6 May 2015.

"Taurus, the Bull." StarDate. U of Texas McDonald Observatory, 2015. Web. 6 May 2015.

Zimmermann, Kim Ann. "Taurus Constellation: Facts about the Bull." Space.com. Purch, 14 Aug. 2012. Web. 6 May 2015.