Arcturus: how to find it and when to see it
Arcturus ranks 4th of the 74 bright stars on our list, at magnitude -0.05, in the constellation Boötes.
You can see it from anywhere north of 71° S, and it's highest in the evening sky in June.
Arcturus at a glance
- Constellation
- Boötes
- Magnitude
- -0.05
- Rank on our list
- 4 of 74
- Hemisphere
- Northern
- Right ascension
- 14 h 16 min
- Declination
- 19.2° north
- Visible from
- north of 71° S
- Never sets
- north of 71° N
- Best evening
- 10 June
- Name from
- Greek
Where Arcturus is in the sky
Arcturus sits 19.2° north of the celestial equator, the line in the sky directly above Earth's equator, so it's in the northern half of the sky. Its right ascension is 14 h 16 min.
Right ascension works like longitude on the sky. It's counted in hours, and about one hour of it turns past you each hour of the night.
When and where to see Arcturus
From the northern hemisphere
From 40° N, the latitude of New York, Madrid and Beijing, Arcturus rises in the north-east, climbs to 69° above the horizon in the south and sets in the north-west.
It's in the evening sky from March to August, and it's highest in the evening around 10 June, in summer.
From the southern hemisphere
From 34° S, the latitude of Sydney, Cape Town and Buenos Aires, Arcturus rises in the north-east, climbs to 37° above the horizon in the north and sets in the north-west.
It's in the evening sky from April to July, and it's highest in the evening around 10 June, in winter.
How high Arcturus climbs from each latitude
The evening is about 9 pm local time, or 10 pm in summer time, and later when the sky is still too bright. A star counts as in the evening sky when it's at least 10° above the horizon.
| Latitude | Visibility | Highest point | Evening sky |
|---|---|---|---|
| 60° N | Rises and sets | 49° in the south | Mar to Sept |
| 50° N | Rises and sets | 59° in the south | Mar to Sept |
| 40° N | Rises and sets | 69° in the south | Mar to Aug |
| 30° N | Rises and sets | 79° in the south | Mar to Aug |
| 20° N | Rises and sets | 89° in the south | Mar to Aug |
| Equator | Rises and sets | 71° in the north | Apr to Aug |
| 20° S | Rises and sets | 51° in the north | Apr to Aug |
| 34° S | Rises and sets | 37° in the north | Apr to Jul |
| 45° S | Rises and sets | 26° in the north | May to Jul |
What the name Arcturus means
Arcturus comes from the Greek arktouros, the guardian of the bear. It follows Ursa Major, the Great Bear, across the sky.
Keep the sky of a night that matters
Our star maps show the stars above any place, at the minute you choose, with the constellation lines drawn in. If Arcturus was above the horizon that night, it's on your map, and we print it on museum-grade paper.
Questions about Arcturus
Arcturus is in Boötes. It sits 19.2° north of the celestial equator, at a right ascension of 14 h 16 min.
Arcturus is highest in the evening sky around 10 June. That's summer in the northern hemisphere and winter in the southern hemisphere.
Yes, from anywhere north of 71° S. From 34° S, it climbs to 37° above the horizon in the north.
Arcturus has a magnitude of -0.05, which ranks it 4th of the 74 bright stars on our list. Sirius looks about 3.6 times brighter.
Arcturus comes from the Greek arktouros, the guardian of the bear. It follows Ursa Major, the Great Bear, across the sky.