What it looks like
Hydrus is a mid-sized southern constellation introduced by Petrus Plancius in 1598, drawn as a small water snake. It is unrelated to Hydra, the long water snake of the northern sky — the name is simply the Latin diminutive. It sits between the two Magellanic Clouds and contains Beta Hydri, one of the nearest bright stars to the Sun.
Brightest stars
Hydrus has no first-magnitude stars; its brightest, Beta Hydri, sits near magnitude 2.8.
| Star | Magnitude | Distance | Meaning |
|---|---|---|---|
| Beta Hydri | +2.80 | 24 ly | — |
| Alpha Hydri | +2.86 | 71 ly | — |
| Gamma Hydri | +3.26 | 214 ly | — |
| Delta Hydri | +4.08 | 135 ly | — |
Mythology and history
Hydrus has no ancient mythology. It was created in 1598 by Petrus Plancius and named after the small water snake, following a Dutch navigational tradition.
A snake of the southern seas
Hydrus was introduced by Petrus Plancius in 1598, using star positions recorded by Dutch navigators on their East Indies voyages. It was included by Bayer in the Uranometria of 1603 and has been part of the sky ever since. The name is the Latin diminutive of Hydra, but the two constellations have no mythological connection — Hydra, the great water snake of Heracles's second labour, lies in the northern sky, while Hydrus is a modest southern pattern circling the south celestial pole.
How to find it
Look between the Large and Small Magellanic Clouds on summer and autumn evenings from the southern hemisphere.
- Find the two Magellanic Clouds; Hydrus lies between them.
- Beta Hydri is one of the nearest bright stars to the Sun.
- Best from the southern hemisphere on summer and autumn evenings.
Key facts
- Abbreviation
- Hyi
- Genitive
- Hydri
- Meaning
- The Lesser Water Snake
- Brightest star
- Beta Hydri
- Main stars
- 5
- Area rank
- 61st
- Best visible
- November
- Declination
- -70°
- Meteor showers
- —
- Neighbours
- Dorado, Reticulum, Horologium, Eridanus, Phoenix, Tucana, Octans, Mensa
Deep-sky objects
Hydrus contains the Small Magellanic Cloud's southern edge and several faint galaxies, including NGC 1511. Beta Hydri is a yellow subgiant often cited as a nearby analogue of the Sun.
Frequently asked questions
What does the constellation Hydrus look like?
Hydrus is a small southern constellation known as the Lesser Water Snake, lying between the Large and Small Magellanic Clouds near the south celestial pole.
What is the brightest star in Hydrus?
The brightest star in Hydrus is Beta Hydri, shining at around magnitude 2.80.
When is Hydrus best visible?
Hydrus is best seen from southern hemisphere during November.
What is the story behind Hydrus?
Hydrus has no ancient mythology. It was created in 1598 by Petrus Plancius and named after the small water snake, following a Dutch navigational tradition.
Which constellations are near Hydrus?
Hydrus borders Dorado, Reticulum, Horologium, Eridanus, Phoenix, Tucana, Octans and Mensa.
Dorado
Tucana