Which constellation is the largest by area?

Which constellation is the largest by area? Hydra is the largest of the 88 modern constellations by area.

Hydra covers approximately 1,303 square degrees, making it larger than any other constellation officially recognized by the International Astronomical Union. It also stretches more than 100 degrees across the sky, so Hydra is both the largest and the longest constellation.

The name Hydra means “water serpent” or “sea serpent.” In Greek mythology, it is commonly associated with the many-headed Lernaean Hydra defeated by Heracles as one of his labors. The modern constellation extends in a long, winding shape across the celestial equator, from the northern sky near Cancer toward the southern regions near Libra and Centaurus.

Hydra’s size can be misleading because it is not packed with exceptionally bright stars. Its brightest star is Alphard, whose name means “the solitary one,” reflecting its relatively isolated position. Hydra was already among the 48 constellations recorded by Ptolemy in the second century, and its large modern boundaries preserve that ancient identity.