The Parramatta Star Catalogue: A New Perspective

Presenter(s): Andrew James

Affiliation(s): Non-Affiliated Independent Amateur Astronomers (NAIAA)

Session details: Saturday, 2016-03-26 00:00:00, LT106

Abstract

The Parramatta Star Catalogue (PSC), made during the 1820s, was the first serious attempt to produce a useable and accurate catalogue of southern stars down to eighth magnitude. It was originally instigated by Sir Thomas Brisbane as a private concern, involving the creation of Parramatta Observatory in Australia, furnishing its astronomical equipment, and hiring the observers, Charles Rümker and James Dunlop. Completed on 2nd March 1822, they began setting up the 5 1/2-foot Troughton Transit Telescope and 2-foot Mural Circle.

Nearly continuous astrometric observations were made from 2nd May 1822 to 1824, becoming more sporadic until they ended on 2nd March 1826. Although the final catalogue is in Brisbane’s name, most of these measures were made by James Dunlop. They were later officially reduced at Royal Observatory, Greenwich, by William Richardson, from the recorded manuscript, then finally published in 1835. At first, the 7385 catalogued stars were heralded as a most significant achievement, but careful examination of the results showed many flaws or significant and inexplicable errors. These were mostly attributed to equipment damage, though others consider that the instrumentation was adjusted too much and that these changes were not properly recorded, or that the observers were not diligent enough and lacked support.

Perhaps the greatest problem of this whole work was the inexcusable large number of missing stars that exist well above the stated catalogue magnitude limit. The presenter has recently created and released a new digital version of this catalogue, that is usefully cross referenced to modern sources. This will be the author’s first presentation regarding some new insights in its astrometric weaknesses, development and overall completeness. (During the NACAA, the author hopes to discuss the upcoming bicentennial of the creation of Parramatta Observatory, and the possibility of an organised special astronomical conference to celebrate the event in 2021 or 2022.)

Biography

Andrew has presented many papers to NACAA between 1980 and 2014. In recent times, Andrew has mainly focused on southern double stars and the historical backgrounds and works of various astronomical discoverers in Australia, including the first southern double star catalogues made by James Dunlop and Charles Rümker. Another associated interest is with Henry Chamberlain Russell, and the various observational assistants, who found and measured many new doubles within the Sydney Observatory Double Star Programme between 1870-1900. Further current investigations have recently extended to a new examination of Sir Thomas Brisbane’s Parramatta Star Catalogue created during the 1820s at Sydney, and its important connection to the discovery of double stars and deep-sky objects. General southern historical accounts and information on double stars and some selected double stars also appear on his popular website, Southern Astronomical Delights. Andrew is still active in the local astronomical scene in Sydney, and has in 2013-15 been a consultant to the design revamp of Sydney Observatory’s new East Dome, used by the public and especially aimed at access by the disabled and seniors. His astronomical experience also extends to lecturing on the subject to Evening Colleges and he has presented many talks over a large range of subjects. He is presently the Planetary Nebula and Deep-Sky Section Leader with the ASNSW though, at this Convention, is an independent presenter as part of a new proposed group of “Non-Affiliated Independent Amateur Astronomers” (NAIAA).