Boötes

Boötes
Constellation
Boötes
List of stars in Boötes
Abbreviation Boö
Genitive Boötis
Pronunciation /boʊˈoʊtiːz/, genitive /boʊˈoʊtɨs/[1]
Symbolism the Plowman
Right ascension 15 h
Declination +30°
Quadrant NQ3
Area 907 sq. deg. (13th)
Main stars 7, 15
Bayer/Flamsteed
stars
59
Stars with planets 5
Stars brighter than 3.00m 3
Stars within 10.00 pc (32.62 ly) 3
Brightest star Arcturus (α Boo) (−0.04m)
Nearest star Wolf 498
(17.71 ly, 5.43 pc)
Messier objects 0
Meteor showers January Bootids
June Bootids
Quadrantids
Bordering
constellations
Canes Venatici
Coma Berenices
Corona Borealis
Draco
Hercules
Serpens Caput
Virgo
Ursa Major
Visible at latitudes between +90° and −50°.
Best visible at 21:00 (9 p.m.) during the month of June.
Other designations: Arctophylax

Boötes is a constellation in the northern sky, located between 0° and +60° declination, 13 and 16 hours of right ascension on the celestial sphere. The name comes from the Greek Βοώτης, meaning herdsman or plowman (literally, ox-driver; from boos, related to the Latin bovis, “cow”). The "ö" in the name is a diaeresis, not an umlaut, meaning that each 'o' is to be pronounced separately.

Boötes was one of the 48 constellations described by the 2nd century astronomer Ptolemy and is now one of the 88 modern constellations. It contains the third brightest star in the night sky, Arcturus.

Contents

Notable features

Stars

τ Boötis, a relatively Sun-like star, is orbited by the massive hot Jupiter planet τ Boötis Ab. It was the fourth extrasolar planet to be discovered and is one of the most studied.

Boötes also hosts a large number of double stars suitable for viewing by amateur astronomers.

Deep sky objects

NGC 5466 is a loose globular cluster that can be observed with most telescopes. It was discovered by William Herschel on May 17, 1784.

The Boötes void, a large section of the universe devoid of galaxies, is located in the area of Boötes.

Boötes Dwarf Galaxy (Boo I dSph) is a faint, tidally disrupted, satellite galaxy of a Milky Way located in Boötes constellation about 197 000 light-years (60 kpc) away from Earth.

History

The former constellation Mons Maenalus, invented by Johannes Hevelius, resided in the southern part of Bootes. It contained only faint stars barely visible to the naked eye.

Mythology

Exactly whom Boötes is supposed to represent is not clear. According to one version, he was a ploughman who drove the oxen in the constellation Ursa Major using his two dogs Chara and Asterion (from the constellation Canes Venatici). The oxen were tied to the polar axis and so the action of Boötes kept the heavens in constant rotation.

Boötes was also supposed to have invented the plough. This is said to have greatly pleased Ceres, the goddess of agriculture who asked Jupiter to give Boötes a permanent fixture in the heavens as a reward for doing this.

Another version portrays Boötes as a grape grower called Icarius, who one day invited the Roman god Bacchus, also called Dionysus, to inspect his vineyards. Bacchus revealed the secret of wine making to Icarius, who was so impressed by this alcoholic beverage that he invited his friends round to sample it. Having never tasted wine before, they all drank too much and woke up the next morning with terrible hangovers; and they made the mistaken assumption that Icarius had tried to poison them. It was decided that Icarius should pay the price with his own life, and he was swiftly murdered in his sleep. Bacchus placed Icarius in the stars to honor him.

Following another reading the constellation is identified with Arcas, son of Zeus and Callisto. Arcas was brought up by his maternal grandfather Lycaon, to whom one day Zeus went and had a meal. To verify that the guest was really the king of the gods, Lycaon killed his grandson and prepared a meal made from his flesh. Zeus noticed and became very angry, transforming Lycaon into a wolf and gave back life to his son.

In the meantime Callisto had been transformed into a she-bear, by Zeus' wife, Hera, who was angry at Zeus' infidelity. When he was grown up, Arcas met with the she-bear and, since obviously he didn't recognize her as his mother, he began to chase Callisto. Callisto, followed by Arcas, sheltered herself in a temple, a sacred place whose profaners were convicted to death. To avoid such fate, Zeus decided to set them in the sky, Arcas as Boötes and Callisto as Ursa Major.

This is a rare version of the myth surrounding Ursa Major, as the myth usually holds that Arcas is transformed into a bear as well (becoming Ursa Minor), and in such versions Boötes has no part. Ursa Minor, and Ursa Major, are constellations whose identification only originated in later classical Greece, and in Rome, and as such Boötes kept separate associations dating from much earlier.

Visualizations

Boötes as depicted in Urania's Mirror, a set of constellation cards published in London c.1825. In his left hand he holds his hunting dogs, Canes Venatici. Below them is the constellation Coma Berenices. Above the head of Boötes is Quadrans Muralis, now obsolete.

Illustrations of Boötes traditionally represent him as a herdsman with a club or staff, holding two hunting dogs on a leash and following Ursa Major around the pole.

Diagram of H.A. Rey's alternative method of connecting the stars of Boötes.

H.A. Rey has suggested an alternative way to visualize the herdsman, in which he is seated and smoking a pipe.[2] The stars ε Boo, δ Boo, μ Boo, β Boo, γ Boo, ρ Boo, and σ Boo form the herdsman's head. In addition, the stars δ Boo, μ Boo, and β Boo may be seen to form a cap. The stars γ Boo, λ Boo, θ Boo, and κ Boo form the herdsman's pipe. Star γ Boo is of the third magnitude and would be the herdsman's mouth. Stars ε Boo, ζ Boo, and α Boo (Arcturus) form the herdsman's body. Star ε Boo is of the third magnitude whereas Arcturus is of magnitude zero. Stars α Boo, η Boo and υ Boo form the herdsman's leg, with η Boo being the knee. Finally, stars υ Boo and τ Boo form the herdsman's foot. Star η Boo is of the third magnitude.

Modern diagrammatic visualizations often depict Boötes as looking like a kite.[3]

Named stars

See also: List of stars in Boötes
Bayer Name Origin Meaning
ά Arcturus Greek guardian of the bears
β Nekkar Arabic constellation name
γ Seginus Arabic name
ε Izar Arabic girdle
η Muphrid Arabic solitary one
μ Alkalurops Arabic herdsman's staff
h Merga Latin rake or hoe
ψ Nadlat Arabic little ones

References

  1. OED
  2. H. A. Rey, The Stars — A New Way To See Them. Enlarged World-Wide Edition. Houghton Mifflin, Boston, 1997. ISBN 0-395-24830-2.
  3. e.g., Tom Polakis, " Celestial Portraits: Boötes and Corona Borealis," from Astronomy Magazine.
  • Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide, Collins, London. ISBN 978-0007251209. Princeton University Press, Princeton. ISBN 978-0691135564.
  • Richard Hinckley Allen, Star Names, Their Lore and Meaning, New York, Dover: various dates, ISBN 0-486-21079-0.
  • Thomas Wm. Hamilton, Useful Star Names, Holbrook, NY, Viewlex: 1968.

External links

Coordinates: Sky map 15h 00m 00s, +30° 00′ 00″