Boötes, the Herdsman

Follow the arc of the Big Dipper to Arcturus

Arcturus, orange and the fourth-brightest star in the night sky, is the base of a kite of stars that runs north toward the Big Dipper's handle: Izar, δ (Qigong), Nekkar, Seginus and ρ Boo.

• Arc to Arcturus: follow the curve of the Big Dipper's handle about 30° away from the bowl to Arcturus.
• Arcturus to Izar: Izar is the brightest star of the kite above Arcturus, about 10° northeast.
• Corona Borealis: the small semicircle of stars just east of the kite is the Northern Crown.

High on spring and early summer evenings

Boötes is highest at 9 pm in June. From mid-northern latitudes Arcturus passes nearly overhead; from the Southern Hemisphere it stays low in the north.

Boötes's best targets are a famous double star and a remote globular

Boötes lies far from the Milky Way and has no Messier objects. One Caldwell object, the galaxy NGC 5248, falls inside its boundary. Its best targets are double stars, led by Izar.

Turned sideways: Arcturus and Muphrid are 37 light-years away

Arcturus and Muphrid are both about 37 light-years away, and only 3.3 light-years apart. Seginus is 87 light-years away, Qigong 122, Izar 203 and Nekkar 225.

The globular cluster NGC 5466 is about 52,000 light-years away, the dwarf galaxy Boötes I 197,000 and NGC 5248 43 million.

Brightest stars in Boötes

Every cataloged object in Boötes

The table above is the short list. Below is everything the major catalogs place inside the IAU boundary of Boötes, mostly galaxies and double stars. Open a catalog to see its brightest members. Each list shows up to 25; longer lists link to the full catalog page.

The Boötes Void and the starlight that opened a World's Fair

• The Boötes Void. In 1981 Robert Kirshner and colleagues found a region about 330 million light-years across in this direction with very few galaxies, one of the largest voids known.
• A fast-moving Arcturus. Arcturus moves across the sky faster than almost any other bright star, about 2.3″ a year. It belongs to a stream of old stars that may have come from a galaxy the Milky Way absorbed long ago.
• Opening the 1933 World's Fair. Light from Arcturus, focused by a telescope onto a photocell, switched on the lights of the Century of Progress fair in Chicago.
• The Quadrantids. Each January 3 to 4 the Quadrantids peak at up to 120 meteors an hour, from a radiant in northern Boötes. They are named for the obsolete constellation Quadrans Muralis, and their parent is the asteroid 2003 EH1.

Boötes video tour

The herdsman driving the bears

The Greeks saw Boötes as a herdsman or plowman driving the bears, Ursa Major, around the pole; Arcturus means "guardian of the bear". In Chinese astronomy Arcturus is Dajiao (大角), the Great Horn of the Azure Dragon.

Constellations bordering Boötes

Boötes shares its IAU boundary with 8 constellations.

• Canes Venatici
• Coma Berenices
• Corona Borealis
• Draco
• Hercules
• Serpens
• Ursa Major
• Virgo