Delphinus constellation: how to find it, when to see it and what is in it
In short
Delphinus (Del) is a equatorial constellation covering 189 square degrees, number 69 of 88 by size. It has no bright stars — the brightest is magnitude 3.6, so you need a dark sky. It is best seen in the evening in September. Over London it rises and sets and is well placed in its season. Its neighbours in the sky: Aquila, Aquarius, Equuleus, Pegasus, Sagitta, Vulpecula.
Area: 189 square degrees, 69 of 88 · Neighbours: Aquila, Aquarius, Equuleus, Pegasus, Sagitta, Vulpecula · Updated 10 October 2026
How to find Delphinus
- 1
When to look
The best time is in September in the evening: in the south, around 21:58.
- 2
Use the neighbours
Find it from the neighbouring constellations: Aquila, Aquarius, Equuleus, Pegasus.
- 3
Brightest stars
The brightest stars of the figure: Rotanev (3.6ᵐ), Sualocin (3.8ᵐ), Aldulfin (4.0ᵐ).
When it is visible over London
| Month | Where and when | Conditions |
|---|---|---|
| January | in the west, around 17:41 | in the evening |
| February | in the east, around 05:44 | low, needs an open horizon |
| March — april | in the east, around 04:47 | before dawn |
| May — june | in the southeast, around 03:24 | before dawn |
| July | in the south, around 02:00 | before dawn |
| August | in the south, around 00:03 | around midnight |
| September — november | in the south, around 21:58 | in the evening |
| December | in the southwest, around 17:14 | in the evening |
Stars of the constellation
| Star | What it is | Magnitude |
|---|---|---|
| Rotanev · β Del | yellow-white subgiant | 3.6ᵐ |
| Sualocin · α Del | blue-white subgiant | 3.8ᵐ |
| Aldulfin · ε Del | blue-white giant | 4.0ᵐ |
| γ² Del | orange subgiant | 4.3ᵐ |
| δ Del | white giant | 4.4ᵐ |
Delphinus FAQ
When is the best time to see Delphinus?
Where is Delphinus in the sky?
What is the brightest star in Delphinus?
Neighbouring and other constellations
Related
Constellation lines: Stellarium, CC BY-SA · star names: IAU WGSN, CC BY 4.0