COSMOS / CONSTELLATIONS / BOO
Boötes (Herdsman)
The Herdsman. IAU abbreviation Boo. One of the 48 classical constellations listed by Ptolemy in the Almagest in the 2nd century AD.
STAR CHART
KEY FACTS
- IAU abbreviation
- Boo
- Latin name / genitive
- Boötes / Boötis
- Position
- Right ascension ≈ 14 h 37 m; declination +8° to +55°
- Visibility from Türkiye
- Visible in full from anywhere in Türkiye. When it crosses the meridian its centre stands about 81° above the horizon from Ankara.
- Best time to observe
- Best placed at 21:00 Türkiye time around 28 June.
- Number of stars
- 150 stars brighter than magnitude 6.5 in the catalogue; 31 brighter than 5 and 8 brighter than 4.
INTERACTIVE LAB
Where is Boötes tonight?
The lab opens for Ankara on today’s date. Drag the time slider through the night; the “Best night” button jumps to the date when the constellation is highest at 21:00 (around 28 June). Change the city to compare the view from elsewhere in Türkiye and around the world.
MYTH, HISTORY AND OBSERVING
The herdsman or ploughman who drives the Great Bear around the pole. Arcturus, reached by following the arc of the Big Dipper’s handle, is the fourth-brightest star of the night sky and the brightest north of the celestial equator. The early-January Quadrantids take their name from the obsolete constellation Quadrans Muralis that once occupied this area.
BRIGHTEST STARS
| Star | Magnitude | Distance (light-years) | Spectral type |
|---|---|---|---|
| Arcturus | -0.05 | 37 | K2IIIp |
| Izar | 2.35 | 203 | A0 |
| Muphrid | 2.68 | 37 | G0IV |
| Seginus | 3.04 | 87 | A7IIIvar |
| δ Boo | 3.46 | 122 | G8III |
| Nekkar | 3.49 | 225 | G8III |
| ρ Boo | 3.57 | 160 | K3III |
| ζ Boo | 3.78 | 176 | A3IVn |
Magnitude: apparent brightness; the smaller the number, the brighter the star. Distances derive from parallax measurements and are uncertain for distant stars. Source: HYG v4.1 star catalogue (CC BY-SA 4.0).
SOURCES
Position, visibility and best observing time were computed approximately for this page from the catalogue stars (Ankara, 39.9° N). The 88 constellations were adopted by the IAU in 1922; their boundaries were drawn by Eugène Delporte in 1930.