Constellation · Hydra · Hya

Hydra constellation: how to find it, when to see it and what is in it

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In short

Hydra (Hya) is a equatorial constellation covering 1,303 square degrees, number 1 of 88 by size. Its brightest star is Alphard, a orange bright giant, magnitude 2.0. It is best seen in the evening in April. Over London it rises and sets and is well placed in its season. Its neighbours in the sky: Antlia, Canis Minor, Centaurus, Cancer, Crater, Corvus, Leo, Libra, Monoceros, Puppis, Pyxis, Sextans, Virgo.

Area: 1,303 square degrees, 1 of 88 · Neighbours: Antlia, Canis Minor, Centaurus, Cancer, Crater, Corvus, Leo, Libra, Monoceros, Puppis, Pyxis, Sextans, Virgo · Updated 10 October 2026

How to find Hydra

1
When to look
The best time is in April in the evening: in the south, around 21:31.
2
Use the neighbours
Find it from the neighbouring constellations: Antlia, Canis Minor, Centaurus, Cancer.
3
Brightest stars
The brightest stars of the figure: Alphard (2.0ᵐ), Naga (3.0ᵐ), ζ Hya (3.1ᵐ).

When it is visible over London

Month	Where and when	Conditions
January — march	in the south, around 02:26	around midnight
April	in the south, around 21:31	in the evening
May	in the southwest, around 22:24	low, needs an open horizon
June — september	—	not visible, behind the Sun
October	in the southeast, around 06:04	low, needs an open horizon
November — december	in the south, around 05:58	before dawn

Stars of the constellation

Star	What it is	Magnitude
Alphard · α Hya	orange bright giant	2.0ᵐ
Naga · γ Hya	yellow giant	3.0ᵐ
ζ Hya	yellow bright giant	3.1ᵐ
ν Hya	orange giant	3.1ᵐ
Ashlesha · ε Hya	yellow giant	3.4ᵐ
ξ Hya	yellow giant	3.5ᵐ
λ Hya	orange giant	3.6ᵐ
μ Hya	orange giant	3.8ᵐ