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SPECIAL GENERAL MEETING and The Nature and Legacy of the Paramatta Star Catalogue

Friday 14th October 2016 - 8:00pm

SPECIAL GENERAL MEETING to vote on Life Membership of Richard Jaworski, to be immediately followed by Ordinary Meeting with guest speaker, Andrew James.

Topic:  The Nature and Legacy of the Paramatta Star Catalogue
Speaker:  Andrew James, ASNSW
Venue: Epping Creative Centre - 26 Stanley Road, Epping
Abstract: The Paramatta Star Catalogue (PSC), made during the 1820s, was the first serious attempt to produce a useable and accurate astrometric catalogue of southern stars down to the 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 stellar observations were made from this Observatory from the 2nd May 1822 to mid-1824, but  they became more sporadic until they finally 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 original 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. Regardless of these views, it seems clear that these observers were not diligent enough and lacked the necessary logistical 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 limits. Discussed is the recently created new and expanded digital version of this catalogue, that is usefully cross references to modern and historical sources. Also highlighted are some new insights in its astrometric weaknesses, development and overall completeness.

Although this is in part similar to my abridged NACAA 2016 talk, it has been greatly expanded with many new additions obtained over the last six months. This includes for the first time the deconstruction of the Richardson corrections such as refraction and the aberration of starlight, and the inclusion of some of the 629 Rümker Star Catalogue published in 1835 that were also made at Paramatta Observatory.

Biography: 

Andrew James is a long-time member of ASNSW and is currently the Deep Sky and Planetary Nebulae Section Leader.

 

Event Date: 
Friday, 14 October, 2016 - 20:00
Location: 
Epping Creative Centre, 26 Stanley Road, Epping NSW

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