Sadr: how to find it and when to see it
Sadr ranks 66th of the 74 bright stars on our list, at magnitude 2.23, in the constellation Cygnus.
You can see it from anywhere north of 50° S, and it's highest in the evening sky in September.
Sadr at a glance
Where Sadr is in the sky
Sadr sits 40.3° 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 20 h 22 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 Sadr
From the northern hemisphere
From 40° N, the latitude of New York, Madrid and Beijing, Sadr rises in the north-east, passes almost straight overhead and sets in the north-west.
It's in the evening sky from June to December, and it's highest in the evening around 11 September, in autumn.
From the southern hemisphere
From 34° S, the latitude of Sydney, Cape Town and Buenos Aires, Sadr rises in the north-east, climbs to 16° above the horizon in the north and sets in the north-west.
It's in the evening sky from August to September, and it's highest in the evening around 11 September, in spring.
How high Sadr 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 | Never sets | 70° in the south | All year |
| 50° N | Never sets | 80° in the south | May to Jan |
| 40° N | Rises and sets | Overhead | Jun to Dec |
| 30° N | Rises and sets | 80° in the north | Jun to Dec |
| 20° N | Rises and sets | 70° in the north | Jun to Dec |
| Equator | Rises and sets | 50° in the north | Jul to Nov |
| 20° S | Rises and sets | 30° in the north | Aug to Oct |
| 34° S | Rises and sets | 16° in the north | Aug to Sep |
| 45° S | Rises and sets | 5° in the north | None |
What the name Sadr means
Sadr comes from the Arabic ṣadr, chest. It marks the chest of Cygnus, the Swan.
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 Sadr was above the horizon that night, it's on your map, and we print it on museum-grade paper.
Questions about Sadr
Sadr is in Cygnus. It sits 40.3° north of the celestial equator, at a right ascension of 20 h 22 min.
Sadr is highest in the evening sky around 11 September. That's autumn in the northern hemisphere and spring in the southern hemisphere.
Yes, from anywhere north of 50° S. From 34° S, it climbs to 16° above the horizon in the north.
Sadr has a magnitude of 2.23, which ranks it 66th of the 74 bright stars on our list. Sirius looks about 29 times brighter.
Sadr comes from the Arabic ṣadr, chest. It marks the chest of Cygnus, the Swan.