Star Constellation Facts: Taurus, The Bull

Star Constellation Facts: Taurus, The Bull
Alexander Jamieson’s Celestial Atlas (1822)

Taurus is a zodiacal constellation found to the right (west) of the constellation Orion, and representing a snorting bull charging the mythological hunter from Greek legend. It is the 17th largest constellation in the entire night sky, with its brightest star, Aldebaran (alpha Tauri), being a giant orange star located 65 light years away and depicting the Bull’s Eye.

Represents: Zeus Disguised as a Bull

According to Greek mythology, Taurus represents the beautiful white bull that Zeus transformed himself into in order to abduct Europa, princess of Phoenicia. After he seduced her in Crete, she gave birth to a son who later became king Minos, the first monarch of Crete. In another version of the legend, Taurus represents the beautiful bull King Minos failed to sacrifice to Poseidon, who in punishment made the king’s wife Queen Pasiphae fall in love and mate with the beast, and as a result sire the Minotaur.

Location: A Northern Constellation

Taurus is visible to observers between latitudes +90° and -65°, and although found in the northern sky, it is still visible to observers located south of the equator during the southern summer. Look for Taurus toward the northeast of Orion, and southwest of Perseus, or alternatively locate the famous Pleiades star cluster (M45) halfway along the “back” of the bull, where it appears to be caught between Taurus and the constellation Aries.

Best Seen: Autumn/Winter

In the northern hemisphere, Taurus is best seen in the autumn and winter months, while in the southern hemisphere it can be seen in spring and summer. From northern locations, Taurus appears in the east from October to November just after sunset. During December and January it then gains elevation, to culminate during the first half of January, making this month the best to observe the constellation.

Taurus: The Bull

Shape: Contains “V” shaped Asterism

Apart from the Hyades cluster that is said by some observers to delineate the face and horns of a bull, the shape of a bovine in the sky is not readily apparent. In fact, if it weren’t for the two bright stars Aldebaran and Elnath marking the “chest”, and “head” of the creature respectively, the “Bull” might be invisible to all but those with the most active imaginations.

Notable Stars: Aldebaran (1st Magnitude)

Taurus is home to a great number of multiple star systems, as well as many bright and massive stars. Below are some of the principal stars of the constellation.

– Aldebaran (Alpha Tauri) is the most luminous star in the constellation, and the 13th most luminous in the entire sky. It is an orange giant (K5III) that is more than 44 times bigger than the Sun and at least 425 times as bright, with an apparent visual magnitude that varies between 0.75 and 0.95, making it a type LB semi-regular variable star. Aldebaran is about 65 light years away, and although it seems to be the brightest star in the Hyades cluster, it is in fact a foreground star relative to the cluster, which is about 150 light years away. Being close to the ecliptic, Aldebaran can be occulted by the Moon.

Star Constellation Facts: Taurus, The Bull– Elnath (Beta Tauri), the second most luminous star in Taurus, is a blue giant star (B7III) located 131-light year from Earth. It it at least 700 times as bright as our sun, an shines with an apparent visual magnitude of 1.68. Like Aldebaran, Elnath is close to the ecliptic, and therefore can also be occulted by the Moon.

– Alcyone (Eta Tauri), the constellation’s third brightest star, is a multiple system situated about 440 light years from our solar system with an apparent mgnitude of 2.87. The primary star, Alcyone A, is a blue-white giant (B7IIIe) that is 10 times bigger than the Sun, 6 times more massive, and 2,400 times brighter. Its closest binary companion is separated by 0.031 arcseconds, giving the pair an orbital period of around 4 days. Alcyone is also the brightest star to be found in the Pleiades open cluster, with its name derived from the Greek for “The Central One”.

– Pectus Tauri (Lambda Tauri) is a triple star system located about 480 light years away with an apparent visual magnitude of 3.47. The primary star in the system, Lambda Tauri AB, is a blue class B3V star about 6 times bigger than the Sun, 7 times more massive, and at least 5,800 times brighter. It has a close binary companion, with the eclipsing binary system’s combined visual magnitude varying between 3.37 and 3.91 over their 3.95 day orbital period. Both stars are rapid spinners, with equatorial rotational velocities of 85km/sec, and 76 km/sec respectively. There is also a third component, λ Tau C, that orbits the inner pair every 33 days. Pectus Tauri means “the bull chest” in Lain.

– 119 Tauri is remarkable for its sheer bulk, and the fact it is the night sky’s second reddest star after Mu Cephei (the Garnet Star) in Cepheus. 119 Tauri is a red supergiant (M2Iab-Ib) located about 1,800 light years away that has an apparent visual magnitude which varies slightly from 4.32 to 4.54 over a period of 165 days. It is about 600 timesbigger than the Sun, 14 times more massive, and 44,000 times brighter.

Notable Objects: Many Famous Star Clusters

Taurus is home to some of the best known star clusters in the sky; M45 (Pleiades Cluster) has been known for at least 15,000 years, with the Hyades Cluster (Caldwell 41) for only slightly less.

Pleiades and Hyades
The Hyades (lower left) and the Pleiades (upper right) in the constellation of Taurus

-The Pleiades (M45) is one of the most beautiful open star cluster in the night sky, as well as one of the most easiest to spot. It is located about 440 light-years away, and has an apparent visual magnitude of 1.6, with estimates on the cluster’s age ranging from 100 million to 10 million years old. What is certain, however, is that all the stars in the cluster formed from the same material, and all the stars in the cluster share a common motion across the sky. Its brightest nine stars are named after the the Seven Sisters from Greek mythology, although just seven of these young blue stars can be seen with the naked eye. It is estimated that this cluster actually contains up to 1,000 stars.

– The Hyades Cluster (Caldwell 41) is a “V” shaped group of stars found at the head of the Taurus constellation,  which at just 151 light-years distant is the nearest open cluster to our own solar system. Its name derives from the Greek ‘to rain’ as their reappearance in the night sky coincided with the start of the winter rains. They are around 20 stars visible to the nake eye, although the Hyades cluster actually contains up to 400 stars, many of which are orange-giant stars around 700 million years old.

– The Crab Nebula (M1), situated about 6,500 light-years away, is actually the remnants of a supernova explosion  which was seen from Earth in 1054 BCE. At its peak the supernova attained a magnitude of -4, but is now of just magnitude 8.4, and can only be seen through a telescope.

Meteor Showers: The Taurids

The constellation has two meteor showers associated with it, namely The Taurids, and The Beta Taurids:

– The Taurids is one of the oldest known meteor showers, and consists of two branches; the Northern Taurids that runs from October 12th to December 2nd, with a peak that stretches from November 4th to November 7th; and the Southern Taurids that runs from September 17th to November 27th with a seven-day peak from October 30th to November 7th. Both branches have peak rates of about 7 meteors per hour.

– The Beta Taurids is a daytime shower that runs from June 5th to July 18th, with a peak that stretches over a few days on either side of June 29th. Observers who have access to radar equipment can expect to see about 25 meteors per hour during the peak.

Planets: 10 Stars with 12 Planets

As of 2017, there have been 10 stars with 12 confirmed planets between them discoverd in Taurus, with one star having a planet with a potentially habitable moon.

Astrological Associations

In astrology, the Sun passes through the sign Taurus from April 21st to May 21st, while in astronomy the Sun passes through the constellation from May 14th to June 19th, which is about one month later. Other astrological associations are:

Date of Birth: April 20 to May 20
Sign Ruler: Venus
Element: Earth
Birth Stone: Emerald
Metal: Copper
Color: Pink
Characteristics: Romantic, logical, patient, benevolent
Compatibility: Capricorn, Virgo and Taurus

Star Lore

As old constellations go, Taurus counts among the oldest, with its history dating back thousands of years. The famous 16,500 year-old map on a cave wall at Lascaux in France is believed to depict the stars in Taurus and the Pleiades, and shows that the constellation was recognised as a bull 15,000 years ago. Thus, when Ptolemy catalogued Taurus as one of the zodiacal constellations around 150 AD, the constellation was already well known in almost all cultures across the world.

In ancient Babylonia, Taurus was known as “MUL.APIN”, meaning “The Heavenly Bull”; in reference to a battle between Gilgamesh and the Bull that was sent by the goddess Ishtar to kill Gilgamesh in revenge for spurning her. In classical Mesopotamian depictions, Gilgamesh is sometimes shown as Orion aiming his drawn bow at the Bull. Taurus also contains one of very few celestial objects mentioned by name in the Bible; the Book of Job in the Old Testament contains this phrase- “Canst thou bind together the brilliant Pleiades?” which phrase forms part of a discussion between God and Job.

Mythology of the Pleiades and Hyades

Atlas, the Titan who held up the Earth on his giant shoulders, and his wife Pleione had 7 daughters collectively known as the Pleiades, namely Maia, Electra, Alcyone, Taygete, Asterope, Celaeno and Merope. After becoming the target of Orion’s affections, and being chased across the world, Zeus subsequently transformed them into a flock of doves (“Pleiades” in Greek”), and set them in the heavens as the seven sisters. One of the sisters, Merope, however, is invisible out of shame for having married Sysiphus, a mortal man.

Atlas had a further 7 daughters by Aethra. The Hyades, as they were know, wept so bitterly after the death of their brother, Hyas, that Zeus took compassion on them and set them as a cluster of stars at the head of the constellation Taurus.

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