Boötes
What is Boötes?
Constellations· Spring–early summer (N) · a kite at the end of the Dipper's arc. The herdsman who drives the bears. A kite-shaped figure hung from orange Arcturus, reached by following the arc of the Big Dipper's handle. Arcturus is the brightest star in the northern sky and a fast-moving visitor from the galactic halo.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Boötes is in your sky right now: https://nowsky.org/solar/sky?sel=con:Boötes — location and time set automatically, no login.
Stars of the figure
| Star | Magnitude |
|---|---|
| Arcturus | 0.0 |
The 1 brightest of the 7 stars used in the figure (7 lines). Lower magnitude means brighter.
Deep-sky objects near this constellation
Constellation basics
| Season | spring to early summer, April–July |
|---|---|
| Brightest star | Arcturus (0.0, brightest in the northern sky) |
| How to find | follow the arc of the Big Dipper's handle |
| Area rank | 13th of 88 |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Frequently asked
- When can I see Boötes?
- spring to early summer, April–July.
- How do I find Boötes?
- follow the arc of the Big Dipper's handle.
- What is the brightest star in Boötes?
- Arcturus, magnitude 0.
- Where is Boötes in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
The light of Arcturus that opened the 1933 Chicago fair
On the evening of 27 May 1933 the Chicago World's Fair opened not with a switch but with starlight. Four observatories aimed telescopes at Arcturus, collected its light on photocells and turned it into an electrical signal that lit the fairgrounds. The star was chosen because its distance was then put at 40 light-years, so that light leaving it during the previous Chicago fair of 1893 would arrive that day.
Arcturus is now measured at 37 light-years, so the light had actually left in 1896, but the point carried. The event let the public feel in a tangible way that starlight really crosses time, and it was also an early public demonstration that photocells respond to the light of a star. The orange star of the herdsman on spring evenings is remembered as the source of the light that opened a city's festival.
The constellation in depth
Boötes is the herdsman, or bear-keeper, who drives Ursa Major and Ursa Minor around the pole; the name Arcturus itself means "guardian of the bear" in Greek. Other tales make him the farmer who invented the plough, or Arcas, son of Callisto, the nymph who became the Great Bear. The Greeks knew the constellation early — Homer mentions it in the Odyssey as a guide for Odysseus's night sailing.
Arcturus is a red giant 37 light-years away and 25 times the Sun's diameter. It belongs to the galaxy's halo rather than its disk, so it moves against its neighbours at over 120 km per second and will visibly shift position over thousands of years. The 1933 Chicago World's Fair was opened with light from Arcturus focused onto photocells.
On spring evenings follow the curve of the Big Dipper's handle and you arrive at orange Arcturus. North of it fainter stars, including Izar, sketch a kite or an ice-cream cone. Izar splits in a small telescope into a lovely orange-and-blue pair. Set the Sky view to a May evening to trace the figure. The constellation also lends its name to the Boötes Void, a vast nearly empty region of space some 330 million light-years across.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.