Leviathan of Parsonstown

The Leviathan of Parsonstown is a giant historic reflecting telescope at Birr Castle in Birr, Ireland, once the largest telescope on Earth.

About the Leviathan of Parsonstown

Also called the Rosse six-foot telescope, the Leviathan has a 72-inch (1.83-metre) aperture and stands on the grounds of Birr Castle in Parsonstown, now the town of Birr, in County Offaly, Ireland.

History

William Parsons, 3rd Earl of Rosse, built the telescope on his estate between 1842 and 1845. It held the record as the world's largest telescope from 1845 until 1917, when the 100-inch Hooker Telescope was completed in California.

Telescopes & research

With its huge mirror, the Leviathan was used to observe spiral nebulae, resolving several of them into individual stars, most famously Messier 51, the Whirlpool Galaxy, whose spiral structure hinted at the existence of what we now know are separate galaxies. Between 1874 and 1878, astronomer J. L. E. Dreyer used the telescope at Birr to compile the New General Catalogue of Nebulae and Clusters of Stars, still a standard reference today.

Location & getting there

The telescope stands within the grounds of Birr Castle Demesne in County Offaly, Ireland, in the Irish midlands.

Visiting the Leviathan of Parsonstown

The telescope and its surrounding castle demesne are open to visitors; check the official Birr Castle website for current opening times and ticket prices before you travel.

See your named star from here

A telescope built to hunt for distant galaxies is also a striking place to look for a star named in your honour. Name your own star or search the star catalogue to find the coordinates of a star already registered.