Which is the largest of the 88 modern constellations?

Hydra is known to be the largest of the 88 modern constellations, measuring 1303 square degrees, and also the longest at over 100 degrees. Its southern end borders the constellations Libra and Centaurus and its northern end borders Cancer. It was included among the 48 constellations listed by the 2nd century astronomer Ptolemy. Commonly represented as a water snake, it straddles the celestial equator.

In spite of its size, Hydra is not particularly prominent or easily recognizable. Its brightest star, the orange giant Alphard, has an apparent magnitude of 2.0, which makes it only moderately bright. Its traditional name means ‘The Solitary One’.

The constellation Virgo is the second largest, measuring 1294 square degrees. Ursa Major and Hercules ranks 3rd and 5th, measuring 1280 square degrees and 1225 square degrees, respectively.