Hydra Constellation

Hydra Constellation is the largest and the longest in the night sky. It occupies an area of 1303 square degrees in the night sky. It lies in the second quadrant of the Southern Hemisphere. The term Hydra means ‘the water snake’.

This constellation represents the sea serpent that Hercules was forced to defeat as one of his twelve labours. Alphard is the brightest star of this constellation. Alphard means ‘the solitary one’ as it is the only star to lie in a fairly blank area of sky.


Quick Facts: –

  • This constellation belongs to the Hercules family. It is the largest family that consists of 19 constellations.
  • Hydra’s head is located south of the Cancer constellation and the tail lies between Libra and Centaurus.
  • Greek astronomer Ptolemy was the first one to catalogue this constellation.
  • It is best visible at 9:00 PM during the month of April.
  • This constellation contains three Messier objects which are Messier 48, Messier 68 and Messier 83.
  • You can only see M48, an open star cluster from the Northern Hemisphere.
  • There are two meteor showers originated from Hydra that are the Alpha Hydrids and the Sigma Hydrids.
  • Alpha Hydrids runs from January 15th to 30th. It peaks around the 20th of January when 10 meteors per hour can be seen.
  • Sigma Hydrids runs from December 5th to 15th.
  • Western cultures believe that Hydra constellation represents a female water snake and its male counterpart is Hydrus.
  • The dimmest star of this constellation is HD 100623.