Universe Guide

Hydrus, The Water Snake Constellation

Hydrus Constellation Star Map

Hydrus (Pronounciation:Hide-rus, Abbrev:Hyi, Latin:Hydri) is a constellation, one of 88 constellations that the night sky is divided into. The sky is not divided up equally between the constellations. Hydrus takes up 243.035 sq. degrees of the night sky which equates to 0.59% of the night sky. Hydrus is the 61st largest in terms of size in the night sky.

The constellation name means The Water Snake . It was not one of the original constellations that had been devised by Ptolemy, instead it was created by Pieter Dirkszoon Keyser and Frederick de Houtman years later.

There are 6 stars that make up the main constellation. The hipparcos satellite scanned and detailed 659 stars. There are 20 stars that can be seen with the naked eye in the constellation on a very clear night sky.

Hydrus is not a member of the Zodiac group of twelve constellations that appear when the Sun sets. Hydrus is a southern hemispheric constellation which means it can't be seen easily or at all from the northern hemisphere.

There are 11 Extrasolar Planets (Exoplanets) in this constellation that are detailed on this site. There is a dedicated page for exoplanets in Hydrus.

There are no deep space objects that were identified by Charles Messier in this constellation. There are no non-Messier deep space objects in this constellation that are covered at present on this site.

The image at the top right of this page was generated using Night Vision, a free to use and download application by Brian Simspon.

Distance to Hydrus

You can't just go to one location and arrive at the constellation because the constellation is made up of stars at different locations and different distances. The nearest main star in the constellation is at a distance of 24.33 light years and the furthest main star is a distance of 339.40 light years. The average distance to the main stars is 156.85 light years.

Hydrus Star Facts

The caveat of these stars are that they are catalogued on this site. If you know of a star that is nearer or further then do let me know in the comments and I'll add it to the site. The stars mentioned are from the Hipparcos catalogue or have been added because of their special status.

Beta Hydri, Hydrus's Nearest Star

The nearest star to Earth is Beta Hydri which is roughly about 24.33 Light Years from the Earth. The nearest star to the Earth with an exoplanet is GJ 3021 which is about 57.07 Light Years.

HIP 120027, Hydrus's Furthest Star

The furthest star that is located in the constellation is HIP 120027 and it is 108721.1 light years away from the Sun. The furthest figure is derived from either the 1997 or 2007 Hipparcos star catalogue parallax figure and it has been known to produce distances that are wrong.

Beta Hydri, Brightest Star in Hydrus

The brightest star in Hydrus is Beta Hydri and is located about 437.29 light years from the Sun. The star has a apparent magnitude of 2.82 but an absolute magnitude of 3.46 when the star is viewed from a distance of 10 Parsecs or 32.6 Light Years. The star is only recognised as being Beta Hydri rather than having Alpha status.

Kappa Hydri, Hydrus's Dimmest Visible Star

The dimmest star that can be seen in Hydrus with the naked eye is Kappa Hydri. The dim star has an apparent magnitude of 5.99. The dimmest star that a person is able to see with their naked eye is 6.0 magnitude based on the table in the reference. Ref: University of Michigan.

Hydrus Mythology

There is no Greek Legend behind this constellation. It was created by Pieter Dirkszoon Keyser and Frederick de Houtman to fill in the voids in the astronomical charts in the southern hemisphere. The Hydrus is a small male water serpent.

Meteor Showers Radiating from Hydrus

There are 3 Meteor Showers that occur during the year within this constellation based on information gathered from Adam Mickiewicz University (Poland). The list below are major ones and which I have a date period for.

NameActivityPeak ActivityClosest Star
Alpha Hydrids15-30 Jan20/21 JanHead of Hydrus

List of Main Stars in Hydrus

The following list contains the stars that make up the constellation. For a larger list of stars in the entire constellation area, please visit the For a list of named stars, that is stars that don't start HD or HIP, please visit Hydrus Star List page.

NameBayerDistance (Lt.Yr.)Right AscensionDeclinationSpectral TypeColour
Head of HydrusAlpha Hydri71.7901h 58m 45.87-61d 34` 11.7F0VYellow/White
Beta HydriBeta Hydri24.3300h 25m 39.20-77d 15` 18.1G2IVYellow
Gamma HydriGamma Hydri214.0203h 47m 14.23-74d 14` 21.3M2IIIRed
Delta HydriDelta Hydri139.6802h 21m 45.02-68d 39` 33.9A3VWhite
Epsilon HydriEpsilon Hydri151.8502h 39m 35.22-68d 16` 01.0B9IIIBlue/White
Nu HydriNu Hydri339.4002h 50m 28.54-75d 04` 00.8K3IIIOrange

Hydrus Facts

Is a Zodiac Sign No
Brightest StarBeta Hydri
Area243.035 sq. deg.
Percentage of Night Sky0.59%
Size Position61st
Hemisphere Southern
Site Exoplanet Count11
Meteor Shower Count3
Nearest StarBeta Hydri
Nearest Star with Exoplanet(s)GJ 3021
Brightest StarBeta Hydri
Dimmest StarKappa Hydri
Furthest StarHIP 120027
Bright Star Count20
Hipparcos Star Count659
Main Star Count6
Messier Deep Space Object Count0
Bordering / Neighbouring / Surrounding ConstellationsEridanus

*Note: The number of Non-Messier Deep Space Object Count relates to how many are covered on this site not how many there are.

List of Deep Space Objects (Galaxies, Nebulas, Supernovas, etc) in Hydrus

NameTypeDistanceDeclinationRight Ascension
NGC 1466Globular Cluster150,000 -71 40 1803 44 33m 0
NGC 602Open Star Cluster-73 33 38.1301 29 32m 133

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