Taurus
Taurus is one of the stars of the winter night sky. It holds Aldebaran, glowing like a red eye, the Pleiades star cluster, and the V-shaped Hyades cluster, all in one place.
| Latin name | Taurus |
|---|---|
| Abbreviation | Tau |
| Brightest star | Aldebaran (mag 0.85) |
| Best seen | Winter evenings (Northern Hemisphere) |
| Astrological dates | April 20 – May 20 |
| Sun actually passes | May 14 – June 21 |
| Stars used by Planetica | 2,159 |
How to find it
Taurus is easy to see in the evening sky from late autumn through winter, roughly November to February. In early January it stands high in the south in the early evening, the best time to observe it.
The easiest way is to start from Orion. Find the three evenly spaced stars of Orion's Belt, then extend that line up and to the right (toward the northwest). You'll first reach Aldebaran, shining bright and orange, and a little farther along the same line you'll find the Pleiades, a tight little dipper-shaped clump of stars.
Around Aldebaran, stars are arranged in the shape of the letter V. This is the Hyades cluster, the Bull's face, and Aldebaran is its red eye. Follow the two arms of the V outward and you reach the tips of the two horns, Elnath and Zeta Tauri. Elnath touches a corner of the pentagon of Auriga. A distinctive feature of Taurus is that only the front half of the Bull is drawn.
With the naked eye you can usually see 6 or 7 stars in the Pleiades, and more if you look slightly to one side (averted vision). Through binoculars, dozens of blue stars sparkle, and it's a gorgeous sight.
The myth: Zeus as a white bull
In Greek mythology, Taurus is the snow-white bull that Zeus turned into. While Europa, a princess of Phoenicia, was picking flowers by the sea with her friends, Zeus approached in the form of a gentle, beautiful white bull. When Europa stroked it and playfully climbed onto its back, the bull dashed into the sea and swam all the way to Crete. There Europa became the mother of King Minos, and the name "Europe" is said to come from her. One interpretation says only the front of the Bull is shown because it is still swimming, with its hindquarters underwater.
The Pleiades are seven sisters, daughters of the Titan Atlas and the sea nymph Pleione. Chased by the hunter Orion, they were turned by Zeus into doves and then into stars, and placed in the sky.
In the East Asian 28 lunar mansions, the Pleiades form the Hairy Head mansion (昴宿), and the Hyades and Aldebaran area form the Net (畢宿). In Korea, the Pleiades were traditionally called "Jomsaengi-byeol," and there was a folk custom of forecasting the year's harvest from the distance between the Moon and the Pleiades.
Main stars
| Name | Apparent magnitude | Distance (approx., ly) | Notes |
|---|---|---|---|
| Aldebaran (Alpha) | 0.85 | ~65 | An orange giant, the Bull's eye. It is much closer than the Hyades, so it isn't actually a member of the cluster. |
| Elnath (Beta) | 1.65 | ~130 | A blue-white star at the tip of the northern horn, touching the pentagon of Auriga. |
| Alcyone (Eta) | 2.9 | ~440 | The brightest star in the Pleiades cluster. |
| Zeta Tauri | 3.0 | ~440 | The star at the tip of the southern horn, with the Crab Nebula right nearby. |
| Ain (Epsilon) | 3.5 | ~150 | An orange giant in the Hyades cluster with a known orbiting planet. |
The Pleiades (M45) is an open cluster about 440 light-years away, a group of young stars roughly 100 million years old. The Hyades, about 150 light-years away, is counted as the nearest open cluster to Earth. Near the tip of the southern horn, the Crab Nebula (M1) is the remnant of a supernova that exploded in 1054; Chinese and Japanese records of the time describe it as a "guest star" bright enough to see in daylight. It lies about 6,500 light-years away, and at its center is a pulsar spinning about 30 times per second.
Birthday sign dates: two different answers
In astrology, Taurus runs from April 20 to May 20. But for most of that period, the real Sun is in Aries. The Sun actually passes through the Taurus constellation from about May 14 to June 21, a long stay of about 39 days.
The biggest reason for the mismatch is precession. Earth's axis slowly turns like a spinning top over a cycle of about 26,000 years, so the vernal equinox point moves west along the ecliptic by about 1 degree every 72 years. The 12 astrological signs divide the ecliptic into equal 30-degree slices from the equinox point, based on the sky of about 2,000 years ago, so roughly a month's worth of drift has built up since then.
Also, the constellation boundaries set by the International Astronomical Union (IAU) in 1930 vary in width. Taurus covers a fairly wide stretch of the ecliptic, so the Sun lingers there a long time. The dates can vary by about a day from year to year.
In Planetica
In Planetica, if your birthday's astrological sign is Taurus, your planetary system is placed next to a real star inside the Taurus constellation. Candidate stars come from the HYG catalog of real star positions and brightnesses. There are 2,159 stars within about 3,000 light-years of Earth that fall inside the IAU boundaries of Taurus.
One of them is chosen at random, and your system settles about 1–6 light-years from it. You might even land next to a star in a crowded spot like the Pleiades or the Hyades. "Twin systems" from people with the same name and birthday all sit in Taurus, but each next to a different star.
Planetica also shows which constellation the Sun was really passing through on your birthday. For example, someone born on May 5 is a Taurus in astrology, but on that day the Sun was actually in Aries.
Fun facts
- In Japan the Pleiades are called "Subaru."
- Elnath used to be shared between Taurus and Auriga, but today it officially belongs to Taurus.
- The Taurid meteor showers seen in autumn are caused by dust left behind by Comet Encke.
Other constellations
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