Perseus constellation: how to find it, when to see it and what is in it
In short
Perseus (Per) is a northern constellation covering 615 square degrees, number 24 of 88 by size. Its brightest star is Mirfak, a yellow-white supergiant, magnitude 1.8. It is best seen in the evening in December. Over London it never sets and is visible all year. Its neighbours in the sky: Andromeda, Aries, Auriga, Camelopardalis, Cassiopeia, Taurus, Triangulum.
Area: 615 square degrees, 24 of 88 · Neighbours: Andromeda, Aries, Auriga, Camelopardalis, Cassiopeia, Taurus, Triangulum · Updated 10 October 2026
How to find Perseus
- 1
When to look
The best time is in December in the evening: in the south, around 21:44.
- 2
Use the neighbours
Find it from the neighbouring constellations: Andromeda, Aries, Auriga, Camelopardalis.
- 3
Brightest stars
The brightest stars of the figure: Mirfak (1.8ᵐ), Algol (2.1ᵐ), ζ Per (2.8ᵐ).
When it is visible over London
| Month | Where and when | Conditions |
|---|---|---|
| January | in the south, around 19:41 | in the evening |
| February | in the southwest, around 18:29 | in the evening |
| March | in the west, around 19:17 | in the evening |
| April | in the northwest, around 21:16 | in the evening |
| May | — | not visible, behind the Sun |
| June | in the northeast, around 02:36 | low, needs an open horizon |
| July | in the northeast, around 03:00 | before dawn |
| August | in the east, around 04:18 | before dawn |
| September | in the south, around 04:43 | before dawn |
| October — december | in the south, around 02:49 | around midnight |
Stars of the constellation
| Star | What it is | Magnitude |
|---|---|---|
| Mirfak · α Per | yellow-white supergiant | 1.8ᵐ |
| Algol · β Per | blue-white main-sequence star | 2.1ᵐ |
| ζ Per | blue-white supergiant | 2.8ᵐ |
| Áldu · ε Per | blue-white main-sequence star | 2.9ᵐ |
| γ Per | yellow giant | 2.9ᵐ |
| Sarvvis · δ Per | blue-white giant | 3.0ᵐ |
| ρ Per | red bright giant | 3.4ᵐ |
| Miram · η Per | orange supergiant | 3.8ᵐ |
Perseus FAQ
When is the best time to see Perseus?
Where is Perseus in the sky?
What is the brightest star in Perseus?
Neighbouring and other constellations
Related
Constellation lines: Stellarium, CC BY-SA · star names: IAU WGSN, CC BY 4.0