Constellations · Constellation · Boötis · Boo
Constellation
Boötes
The herdsman chasing the Great Bear around the pole — shaped like a kite, and holding the brightest star in the northern sky.
- Genitive
- Boötis
- Area
- 907 square degrees · 13th of 88
- Brightest star
- Arcturus · magnitude -0.05
- Naked-eye stars
- 147 brighter than magnitude 6.5
- Highest at midnight
- early May
Look for
Follow the curve of the Big Dipper’s handle away from the bowl: “arc to Arcturus”. Keep going the same way and “speed on to Spica”.
History
In 1933 the light of Arcturus, caught by a telescope and a photocell, switched on the lights of the Chicago World’s Fair. It was thought to have left the star for the previous Chicago fair of 1893; the modern distance is about 37 light-years.
Science
Arcturus is racing through the galaxy’s disc at a steep angle — it may have come from a small galaxy the Milky Way swallowed long ago.