Rasalhague: how to find it and when to see it
Rasalhague ranks 58th of the 74 bright stars on our list, at magnitude 2.08, in the constellation Ophiuchus.
You can see it from anywhere north of 77° S, and it's highest in the evening sky in July.
Rasalhague at a glance
- Constellation
- Ophiuchus
- Magnitude
- 2.08
- Rank on our list
- 58 of 74
- Hemisphere
- Northern
- Right ascension
- 17 h 35 min
- Declination
- 12.6° north
- Visible from
- north of 77° S
- Never sets
- north of 77° N
- Best evening
- July 31
- Name from
- Arabic
Where Rasalhague is in the sky
Rasalhague sits 12.6° 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 17 h 35 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 Rasalhague
From the northern hemisphere
From 40° N, the latitude of New York, Madrid and Beijing, Rasalhague rises in the east, climbs to 63° above the horizon in the south and sets in the west.
It's in the evening sky from May to October, and it's highest in the evening around July 31, in summer.
From the southern hemisphere
From 34° S, the latitude of Sydney, Cape Town and Buenos Aires, Rasalhague rises in the east, climbs to 43° above the horizon in the north and sets in the west.
It's in the evening sky from June to September, and it's highest in the evening around July 31, in winter.
How high Rasalhague climbs from each latitude
The evening is about 9 pm local time, or 10 pm during daylight saving 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 | 43° in the south | May to Oct |
| 50° N | Rises and sets | 53° in the south | May to Oct |
| 40° N | Rises and sets | 63° in the south | May to Oct |
| 30° N | Rises and sets | 73° in the south | May to Oct |
| 20° N | Rises and sets | 83° in the south | May to Oct |
| Equator | Rises and sets | 77° in the north | May to Oct |
| 20° S | Rises and sets | 57° in the north | Jun to Sep |
| 34° S | Rises and sets | 43° in the north | Jun to Sep |
| 45° S | Rises and sets | 32° in the north | Jun to Sep |
What the name Rasalhague means
Rasalhague comes from the Arabic raʾs al-ḥawwāʾ, the head of the serpent charmer. It marks the head of Ophiuchus.
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 Rasalhague was above the horizon that night, it's on your map, and we print it on museum-grade paper.
Questions about Rasalhague
Rasalhague is in Ophiuchus. It sits 12.6° north of the celestial equator, at a right ascension of 17 h 35 min.
Rasalhague is highest in the evening sky around July 31. That's summer in the northern hemisphere and winter in the southern hemisphere.
Yes, from anywhere north of 77° S. From 34° S, it climbs to 43° above the horizon in the north.
Rasalhague has a magnitude of 2.08, which ranks it 58th of the 74 bright stars on our list. Sirius looks about 26 times brighter.
Rasalhague comes from the Arabic raʾs al-ḥawwāʾ, the head of the serpent charmer. It marks the head of Ophiuchus.