Constellation · Southern sky · Fall

Hydrus, the Male Water Snake

HY-drus · genitive Hydri · Hyi

A small water snake winding between the Large and Small Magellanic Clouds near the south celestial pole. Hydrus holds β Hydri, one of the nearest Sun-like stars, and a corner of the Small Magellanic Cloud.

0h 6h 12h 18h
Where Hydrus sits on the whole sky. Gold line: the ecliptic.
Hydrus star chart with deep-sky objects DORADO MENSA RETICULUM TUCANA NGC 602 | Open cluster | mag 13.0 NGC 602 NGC 1466 | Globular cluster | mag 11.6 NGC 1466 NE

Swipe sideways to pan the chart.

Stars to magnitude 8, IAU boundary and stick figure, J2000. Click any object to open its page; click a neighboring constellation's name to go there. Nebula Open cluster Galaxy Planetary nebula Dark nebula Double star
Area
243 sq°rank 61 of 88
Best month
Decemberat 9 pm
Visible from
5°N to 90°S
Brightest star
β Hyi (mag 2.82)
Messier
0none
Caldwell
0none
Cataloged objects
99in 7 catalogs

A triangle of stars between the Magellanic Clouds

Hydrus's three brightest stars, α, β and γ Hyi, make a large triangle between Achernar, the Large Magellanic Cloud and the south celestial pole.

A far-southern constellation, best from October to December

Hydrus is highest at 9 pm in December. It is never seen from mid-northern latitudes; from south of about 25°S it never sets.

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 60°N JAN at 60°N: -47° high at 9 pm FEB at 60°N: -52° high at 9 pm MAR at 60°N: -59° high at 9 pm APR at 60°N: -66° high at 9 pm MAY at 60°N: -73° high at 9 pm JUN at 60°N: -75° high at 9 pm JUL at 60°N: -70° high at 9 pm AUG at 60°N: -62° high at 9 pm SEP at 60°N: -55° high at 9 pm OCT at 60°N: -49° high at 9 pm NOV at 60°N: -46° high at 9 pm DEC at 60°N: -45° high at 9 pm 50°N JAN at 50°N: -38° high at 9 pm FEB at 50°N: -43° high at 9 pm MAR at 50°N: -50° high at 9 pm APR at 50°N: -57° high at 9 pm MAY at 50°N: -63° high at 9 pm JUN at 50°N: -65° high at 9 pm JUL at 50°N: -61° high at 9 pm AUG at 50°N: -53° high at 9 pm SEP at 50°N: -46° high at 9 pm OCT at 50°N: -39° high at 9 pm NOV at 50°N: -36° high at 9 pm DEC at 50°N: -35° high at 9 pm 40°N JAN at 40°N: -28° high at 9 pm FEB at 40°N: -34° high at 9 pm MAR at 40°N: -40° high at 9 pm APR at 40°N: -48° high at 9 pm MAY at 40°N: -54° high at 9 pm JUN at 40°N: -55° high at 9 pm JUL at 40°N: -51° high at 9 pm AUG at 40°N: -44° high at 9 pm SEP at 40°N: -36° high at 9 pm OCT at 40°N: -30° high at 9 pm NOV at 40°N: -26° high at 9 pm DEC at 40°N: -25° high at 9 pm 30°N JAN at 30°N: -18° high at 9 pm FEB at 30°N: -24° high at 9 pm MAR at 30°N: -31° high at 9 pm APR at 30°N: -38° high at 9 pm MAY at 30°N: -44° high at 9 pm JUN at 30°N: -45° high at 9 pm JUL at 30°N: -41° high at 9 pm AUG at 30°N: -34° high at 9 pm SEP at 30°N: -27° high at 9 pm OCT at 30°N: -20° high at 9 pm NOV at 30°N: -16° high at 9 pm DEC at 30°N: -15° high at 9 pm 20°N JAN at 20°N: -8° high at 9 pm FEB at 20°N: -14° high at 9 pm MAR at 20°N: -21° high at 9 pm APR at 20°N: -29° high at 9 pm MAY at 20°N: -34° high at 9 pm JUN at 20°N: -35° high at 9 pm JUL at 20°N: -31° high at 9 pm AUG at 20°N: -25° high at 9 pm SEP at 20°N: -17° high at 9 pm OCT at 20°N: -10° high at 9 pm NOV at 20°N: -6° high at 9 pm DEC at 20°N: -5° high at 9 pm 10°N JAN at 10°N: 2° high at 9 pm FEB at 10°N: -5° high at 9 pm MAR at 10°N: -12° high at 9 pm APR at 10°N: -19° high at 9 pm MAY at 10°N: -24° high at 9 pm JUN at 10°N: -25° high at 9 pm JUL at 10°N: -22° high at 9 pm AUG at 10°N: -15° high at 9 pm SEP at 10°N: -7° high at 9 pm OCT at 10°N: -0° high at 9 pm NOV at 10°N: 4° high at 9 pm DEC at 10°N: 5° high at 9 pm 0° JAN at 0°: 12° high at 9 pm FEB at 0°: 5° high at 9 pm MAR at 0°: -2° high at 9 pm APR at 0°: -9° high at 9 pm MAY at 0°: -14° high at 9 pm JUN at 0°: -15° high at 9 pm JUL at 0°: -12° high at 9 pm AUG at 0°: -5° high at 9 pm SEP at 0°: 2° high at 9 pm OCT at 0°: 9° high at 9 pm NOV at 0°: 14° high at 9 pm DEC at 0°: 15° high at 9 pm 10°S JAN at 10°S: 21° high at 9 pm FEB at 10°S: 15° high at 9 pm MAR at 10°S: 8° high at 9 pm APR at 10°S: 1° high at 9 pm MAY at 10°S: -4° high at 9 pm JUN at 10°S: -5° high at 9 pm JUL at 10°S: -2° high at 9 pm AUG at 10°S: 4° high at 9 pm SEP at 10°S: 12° high at 9 pm OCT at 10°S: 19° high at 9 pm NOV at 10°S: 24° high at 9 pm DEC at 10°S: 25° high at 9 pm 20°S JAN at 20°S: 31° high at 9 pm FEB at 20°S: 24° high at 9 pm MAR at 20°S: 17° high at 9 pm APR at 20°S: 10° high at 9 pm MAY at 20°S: 6° high at 9 pm JUN at 20°S: 5° high at 9 pm JUL at 20°S: 8° high at 9 pm AUG at 20°S: 14° high at 9 pm SEP at 20°S: 22° high at 9 pm OCT at 20°S: 29° high at 9 pm NOV at 20°S: 34° high at 9 pm DEC at 20°S: 35° high at 9 pm 30°S JAN at 30°S: 41° high at 9 pm FEB at 30°S: 34° high at 9 pm MAR at 30°S: 27° high at 9 pm APR at 30°S: 20° high at 9 pm MAY at 30°S: 16° high at 9 pm JUN at 30°S: 15° high at 9 pm JUL at 30°S: 18° high at 9 pm AUG at 30°S: 24° high at 9 pm SEP at 30°S: 31° high at 9 pm OCT at 30°S: 39° high at 9 pm NOV at 30°S: 44° high at 9 pm DEC at 30°S: 45° high at 9 pm 40°S JAN at 40°S: 51° high at 9 pm FEB at 40°S: 43° high at 9 pm MAR at 40°S: 36° high at 9 pm APR at 40°S: 30° high at 9 pm MAY at 40°S: 26° high at 9 pm JUN at 40°S: 25° high at 9 pm JUL at 40°S: 28° high at 9 pm AUG at 40°S: 33° high at 9 pm SEP at 40°S: 41° high at 9 pm OCT at 40°S: 48° high at 9 pm NOV at 40°S: 54° high at 9 pm DEC at 40°S: 55° high at 9 pm below horizon low 20-40° 40-60° overhead-ish
Altitude of the constellation's center at 9 pm local time on the 15th of each month. Computed from its position, for any longitude.

Hydrus's targets lie in the Magellanic Clouds

Hydrus has no Messier or Caldwell objects. Its targets belong to the two Magellanic Clouds at its edges.

Best targets
ObjectTypeMagSizeDistanceBest with
NGC 602NGC 602Open cluster13.03′~200,000 lyImaging
NGC 1466NGC 1466Globular cluster11.63.5′~160,000 lyTelescope
HYDRUS

On each object page: a locator like this one shows where NGC 602 sits in Hydrus. The box marks a 2.5° field, about what 10×50 binoculars show.

Turned sideways: β Hyi is 24 light-years away, NGC 602 200,000

β Hyi is 24 light-years away, α Hyi 72 and γ Hyi 214. NGC 1466 is about 160,000 light-years away and NGC 602 about 200,000.

Hydrus turned sideways: how far away each star and object is STARS YOU CAN SEE MILKY WAY OTHER GALAXIES 10 ly 100 ly 1,000 ly 10,000 ly 100,000 ly 1 million ly 10 million ly 100 million ly EARTH β Hyi: 24 lyβ Hyi24 ly α Hyi: 72 lyα Hyi72 ly γ Hyi: 214 lyγ Hyi214 ly δ Hyi: 140 lyδ Hyi140 ly ε Hyi: 153 lyε Hyi153 ly η2 Hyi: 222 lyη2 Hyi222 ly ν Hyi: 345 lyν Hyi345 ly ζ Hyi: 295 lyζ Hyi295 ly λ Hyi: 217 lyλ Hyi217 ly μ Hyi: 287 lyμ Hyi287 ly NGC 602: ~200,000 lyNGC 602~200,000 ly NGC 1466: ~160,000 lyNGC 1466~160,000 ly
Side view: distance from Earth on a logarithmic scale, each step ten times farther. The vertical position of every star and object is unchanged. Stick-figure lines join only stars with measured distances.

Brightest stars in Hydrus

StarDesignationMagDistanceSpectral class
β Hyiβ Hyi2.8224 lyG2IV
α Hyiα Hyi2.8672 lyF0V
γ Hyiγ Hyi3.26214 lyM2III
δ Hyiδ Hyi4.08140 lyA3V
ε Hyiε Hyi4.12153 lyB9III
η2 Hyiη2 Hyi4.68222 lyG5III
ν Hyiν Hyi4.76345 lyK3III
ζ Hyiζ Hyi4.83295 lyA2IV/V
λ Hyiλ Hyi5.09217 lyK5III
μ Hyiμ Hyi5.27287 lyG4III

Every cataloged object in Hydrus

The table above is the short list. Below is everything the major catalogs place inside the IAU boundary of Hydrus. Open a catalog to see its brightest members. Each list shows up to 25; longer lists link to the full catalog page.

NGC18
DesignationNameTypeMagDistance
NGC 1511galaxy11.349.8 million ly
NGC 1466globular cluster11.5-
NGC 1629globular cluster12.6-
NGC 1473galaxy12.968.9 million ly
NGC 602open cluster13.0-
NGC 802galaxy13.6-
NGC 1557open cluster-
NGC 1511Bgalaxy-
NGC 1511Agalaxy77.3 million ly
NGC 643open cluster-
NGC 643Aopen cluster-
NGC 643Bgalaxy-
NGC 813galaxy-
NGC 643Cgalaxy-
NGC 796open cluster-
NGC 646 NED02galaxy-
NGC 646 NED01galaxy-
NGC 646galaxy pair-
IC2
DesignationNameTypeMagDistance
IC 1708open cluster-
IC 1717other-
Open clusters6
DesignationNameTypeMagDistance
NGC 602Flying Lizard Nebulacluster13.204,000 ly
IC 1708cluster204,000 ly
NGC 643cluster204,000 ly
NGC 643Acluster204,000 ly
NGC 796cluster204,000 ly
NGC 1557asterism-
Arp-Madore galaxies3
DesignationNameTypeMagDistance
AM 359-67411.349.8 million ly
AM 106-80314.0236 million ly
AM 349-71444.5 million ly
Abell galaxy clusters56
DesignationNameTypeMagDistance
Abell S210S116.3-
Abell S225S116.3-
Abell S164S116.3-
Abell 2954616.3-
Abell S191S116.4-
Abell S176S116.4-
Abell S327S116.7-
Abell S322S116.7-
Abell S236S116.7-
Abell S445S116.7-
Abell S158S116.8-
Abell S128S116.8-
Abell S254S116.8-
Abell S432S116.8-
Abell S30S116.8-
Abell S450S116.9-
Abell S211S116.9-
Abell S185S117.0-
Abell S303S117.0-
Abell S194S117.1-
Abell S276S117.1-
Abell 2953617.1-
Abell S196S117.2-
Abell S198S117.2-
Abell 3021717.2-
The 25 brightest of 56 in Hydrus
Exoplanets1
DesignationNameTypeMagDistance
HD 11977 b4.68222 ly
Nearby stars (Gliese)13
DesignationNameTypeMagDistance
Gl 19Beta Hydrii12.8224 ly
Gl 83Alpha Hydrii12.8672 ly
Gl 97.1Delta Hydrii14.08140 ly
NN 302116.5957 ly
Gl 81.218.6166 ly
NN 316718.8475 ly
Gl 127.1A211.3934 ly
Gl 85111.5240 ly
NN 3243211.9554 ly
NN 3141112.2548 ly
NN 3112113.8832 ly
GJ 2028214.0882 ly
Gl 127.1B214.7334 ly

An older Sun

  • β Hydri. A Sun-like star a little older than the Sun, starting to swell into a subgiant: a preview of the Sun's future, studied closely by asteroseismology.

Hydrus video tour

Hydrus Constellation Deep Sky Tour · Watch on YouTube

The water snake

Hydrus is one of the 12 constellations from the voyages of Keyser and de Houtman in the 1590s. In Chinese astronomy it is Shewei (蛇尾), the Snake's Tail.

Constellations bordering Hydrus

Hydrus shares its IAU boundary with 7 constellations.