The Armagh Observatory

Archbishop Richard Robinson (1708-1794), leader of the Church of Ireland, created the Georgian town of Armagh, including the Observatory. A rich and influential man, he embodied the spirit of the age - what became known as the enlightenment, which was marked by a steady increase in the study of the sciences. He was influenced to found an observatory by the Reverend J.A. Hamilton of Cookstown, County Tyrone, who was a noted amateur astronomer, and was to become its first director.

The building was designed by Francis Johnston, the architect responsible for many fine buildings in Dublin, most notably the GPO in O'Connell Street and the Chapel Royal. Construction was completed in 1793, and along with Dunsink Observatory in Dublin, built in 1785, it was one of the first observatories where what mattered was how good it was for observing - not how pleasing it looked to the eye. Nevertheless, it is an imposing example of the elegance of Georgian architecture.

Armagh Observatory in the Winter

 J.A. Hamilton, the first director, embarked on a comprehensive program of accurately measuring the positions of the stars, but was hindered by the death of Archbishop Robinson in 1794. Robinson's successors took little interest in science, which resulted in the loss of a number of instruments originally ordered for the Observatory. However, Hamilton struggled on with his astronomy, and also initiated a series of weather readings which are still carried out today, at the meteorological station to the south of the main buildings.

In 1823, a young and gifted astronomer called Thomas Romney Robinson (no relation to Archbishop Robinson!) was appointed director, a post he held for a remarkable 59 years. He was fortunate in that before he took up his post, a new Archbishop was created - John George Beresford - who was an enthusiastic supporter of the Observatory, and, fortunately for the Observatory, rich. With this combination of ability and financial backing the Observatory flourished during the mid-19th century, acquiring the long-needed collection of good quality instruments - such as can be found in the telescope domes at the back of the building. It was during this period that Armagh became established as a scientific institution of national and international importance.

John Louis Emil Dreyer, a Dane, took over as director upon Robinson's death in 1882. While at Armagh he compiled the NGC catalogue, or more properly the "New General Catalogue of Nebulae and Clusters of Stars". Over a century later it is still the principle catalogue of nebulae and galaxies used by the astronomical community, and is probably the single most important contribution to science to have come from Armagh Observatory.


Ernst Julius Opik was a famous astrophysicist who worked at Armagh from 1948 until 1981. His most notable achievements include the discovery of white dwarfs - stars that have run out of fuel. He was the first to calculate evolutionary models of stars with variable compositions, he proved that the great spiral nebula in Andromeda was another galaxy, and was among the first to seriously suggest that the Ice Ages were caused by variations in the amount of energy given off by the Sun. His work on asteroid impacts and craters on Mars hit the headlines.

For more information, visit the Observatory's web-site.

Last Revised: 2010 January 29th