Arcturus: Bear-Guard

Arcturus is an orange giant, and the fourth brightest star in the sky. Its moment of earthly fame came during the Chicago World Fair of 1934. There had been a World Fair in Chicago in 1893, and they calculated that light leaving Arcturus then would arrive in time for the new Fair.*

The Space.com site describes it:

At 9:15 p.m. Central Time on May 27, 1933, telescopes focused the star’s light on several photoelectric cells. The current was used to flip a switch that turned on the floodlights at the expedition grounds.

Arcturus has also made appearances in fiction, including a book called A Voyage to Arcturus, by David Lindsay, in which the hero travels to the planet Tormance. (Ironically, as far as can be seen, Arcturus has no planets.) It has also appeared in Dr. Who, Star Trek, Aliens, and The Hitchhiker’s Guide to the Galaxy.

BootesMysterygood

Bootes and the Big Dipper, from astrobob.

The main star of Boötes gets its name from the Latin transliteration of the Greek “Bear-Guard”. Its proximity to Ursa Major and Minor, along with its brightness (4th brightest star), made it noticeable. This led to a Greek myth about why the two were so close: Bootes was the son of the nymph Callisto, and Zeus. His wife, Hera, reacted with her usual anger and changed Callisto into a bear. Many years later, when Arcturus (or Arcas) was out hunting, he came across the bear and chased it, Zeus had to intervene, and placed Callisto in the sky, as the Great Bear.

Zeus seems to have continually been saving this family from each other. Arcas’ grandfather, Lycaeon, was to give a dinner for the head of the gods, but he began to doubt that this stranger was indeed Zeus. To test him, Lycaeon killed his grandson, and had him cooked and served to their guest. The enraged god changed Lycaeon into a wolf, and restored the boy to life. When he grew older, he encountered his mother in bear form and the rest of the myth follows from there.

 Boötes, in Uranographia by Johannes Hevelius (1690).

Boötes, in Uranographia by Johannes Hevelius (1690).

Despite this myth, in European folklore Bootes was often the Herdsman to Orion’s hunter. Since Orion is visible throughout fall and winter, and sets in late spring, when Bootes is becoming visible, the hunter – herdsman opposition was probably inevitable.

Another myth tells how Bootes was robbed of everything by his brother, and wound up as a wanderer. After travelling about, he invented the plough, making farmers’ lives a lot easier. As a reward, Demeter placed him among the stars as the ploughman. Boötes is close to Ursa Major, and could be seen as the driver of the Plough, as it is sometimes called.

Bayley suggests that the Welsh hero Hu Gadarn could be Bootes, since he was the first use a plough, and tame oxen to that use. (Hu Gardarn also lead the Welsh into Britain and Brittany, so he was a true culture-hero like Osiris and Isis, who also taught agriculture to their people.)

The Babylonians, too, saw an agricultural side to Bootes, and called Arcturus Sib-zi-anna, “Shepherd of the Flock of Heaven”.

As you can see in the picture above, Bootes is shaped like a kite or ice-cream cone, with Arcturus at the bottom. It is a very odd star in some ways, including its motion through the galaxy. Most stars move along the flat disc of our Milky Way galaxy, but Arcturus is one of 52 stars that are moving perpendicular to all the others. These are called the Arcturus Stream, and their motion means that in about another 4000 years Arcturus will be a lot closer to our star. At some point in the distant future, its motion will make it invisible from Earth.

Arcturus was connected with lances by both the Arabs and the Greeks; the Arabs called it the Lofty Lance-Bearer, Al Simak al Ramih, with the rest of Boötes supplying the lance, while a similar name appeared in the Graeco-Persian star tables, Javelin-bearer.

The Norse, more prosaically, used Arcturus as a marker of time, and called it the Day Star. The Chukchis of Siberia used Arcturus and Vega as guide-stars when they were hunting. They called them the Heads, with Arcturus as the Front Head (YanoLa’ut), and Vega the Back Head (YaaLa’ut). The Chukchis called them brothers or cousins, with Arcturus as the chief or guide of all the stars.

Finally, in astrology, Arcturus means riches, honours, wealth from sea-voyages, and a tendency to excess.

* Their calculations were actually out by a bit, since later refinements to space observation showed that Arcturus is 37, not 40 light-years away.


Allen, Richard H. 1963: Star Names: Their Lore and Meaning, Dover Publications. (reprint)
Bayley, Michael 1997: Caer Sidhe vol. 1: The Celtic Night Sky, Capall Bann.
Eratosthenes, C. Julius Hyginus, trans. Condos, Theony 1997: Star Myths of the Greeks and Romans: A Sourcebook, Phanes Press.

Star map at the top from Wikimedia.

One thought on “Arcturus: Bear-Guard

  1. Pingback: Spica: the Wheat Sheaf – We Are Star Stuff

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s