Serpens constellation: how to find it, when to see it and what is in it
In short
Serpens (Ser) is a equatorial constellation covering 637 square degrees, number 23 of 88 by size. Its brightest star is Unukalhai, a orange giant, magnitude 2.7. It is best seen in the evening in July. Over London it rises and sets and is well placed in its season. Its neighbours in the sky: Aquila, Boötes, Corona Borealis, Hercules, Libra, Ophiuchus, Scutum, Sagittarius, Virgo.
Area: 637 square degrees, 23 of 88 · Neighbours: Aquila, Boötes, Corona Borealis, Hercules, Libra, Ophiuchus, Scutum, Sagittarius, Virgo · Updated 10 October 2026
How to find Serpens
- 1
When to look
The best time is in July in the evening: in the southwest, around 23:00.
- 2
Use the neighbours
Find it from the neighbouring constellations: Aquila, Boötes, Corona Borealis, Hercules.
- 3
Brightest stars
The brightest stars of the figure: Unukalhai (2.7ᵐ), η Ser (3.3ᵐ), μ Ser (3.5ᵐ).
When it is visible over London
| Month | Where and when | Conditions |
|---|---|---|
| January | in the southeast, around 06:26 | before dawn |
| February — april | in the south, around 05:44 | before dawn |
| May | in the south, around 01:09 | around midnight |
| June | in the south, around 23:21 | in the evening |
| July — september | in the southwest, around 23:00 | in the evening |
| October | in the west, around 19:19 | in the evening |
| November | in the west, around 17:28 | low, needs an open horizon |
| December | in the southeast, around 06:29 | before dawn |
Stars of the constellation
| Star | What it is | Magnitude |
|---|---|---|
| Unukalhai · α Ser | orange giant | 2.7ᵐ |
| η Ser | orange giant | 3.3ᵐ |
| μ Ser | white main-sequence star | 3.5ᵐ |
| ξ Ser | yellow-white subgiant | 3.5ᵐ |
| Zhou · β Ser | white subgiant | 3.7ᵐ |
| ε Ser | white main-sequence star | 3.7ᵐ |
| δ Ser | yellow-white subgiant | 3.8ᵐ |
| Muning · γ Ser | yellow-white main-sequence star | 3.8ᵐ |
Serpens FAQ
When is the best time to see Serpens?
Where is Serpens in the sky?
What is the brightest star in Serpens?
Neighbouring and other constellations
Related
Constellation lines: Stellarium, CC BY-SA · star names: IAU WGSN, CC BY 4.0