Andrew Ainslie Common
| Andrew Ainslie Common | |
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 Andrew Ainslie Common
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| Born | August 7, 1841 Newcastle Upon Tyne |
| Died | June 2, 1903 |
| Residence | Ealing, London |
| Citizenship | English |
| Fields | Astronomy |
| Known for | astrophotography |
Andrew Ainslie Common FRS (1841 – 1903) was an English amateur astronomer[1] best known for his pioneering work in astrophotography.
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[edit] Biography
Common was born in Newcastle Upon Tyne on August 7, 1841. His father, Thomas Common, a surgeon known for his treatment of cataract, died when Andrew was a child forcing him to go early into the world of work. In the 1860s he teamed up with an uncle in the sanitary engineering firm of Matthew Hall and Company. He married in 1867. In 1890 he retired from Matthew Hall. Andrew Ainslie Common died of heart failure June 2, 1903.
[edit] Work in astronomy
Although Common’s professional career was in the field of sanitary engineering, he is most noted for the work he did as an amateur in the field of astronomy. As a child Andrew showed interest in astronomy. At age 10 his mother borrowed a telescope for him to use from a local doctor. He returned to astronomy in his 30’s when he took up experimenting with gelatin plate photography of the moon and plants with 5.5 inch refracting telescope.
In 1876 Common became a Fellow of the Royal Astronomical Society. About this time he also moved to Ealing outside London where he would live for the rest of his life operating an astronomical observatory from back yard of his house. Common realized he would need very large telescopes to gather enough light to record the images of stars photographically so he began building a series of ever larger Newtonian reflecting telescopes using the then new technology of silver coated glass mirrors. For the first of these, a telescope of his own design constructed in 1876, he tried to grind and polish his own 17 inch mirror but gave up on the idea and ordered an 18 inch (46 cm) mirror from the optical firm of George Calver of Chelmsford. In 1877 and 1878 he published several articles on his visual observations of the satellites of Mars and Saturn.
- The 36-inch reflector
In 1879 he bought a new 36-inch (910 mm) mirror from Calver to mount in a larger Newtonian reflecting telescope he was building. He used it to make further observations of satellites of Mars and Saturn, and was able to see Saturn’s moon Mimas and show that the ephemeris of its orbit was incorrect. With this instrument he also obtained a photograph of a comet in 1881, C/1881 K1. His most notable work with this telescope were the long time exposures he made of the Orion Nebula between 1880 and 1884. His 1883 photograph of that nebula for the first time showed films ability to record stars and other features invisible to the human eye. Common noted of his own photographs that:
- "although some details are lost in the enlargement, sufficient remains to show that we are approaching the time where a photograph will give us the means to recording in its own inimitable way the shape of a nebula and the relative brightness different parts, in a better manner than the most careful hand drawing”.
These pictures earned Common the Gold Medal of the Royal Astronomical Society in 1884. Common eventual sold the 36 reflector to British politician Edward Crossley who gave it to Lick Observatory in 1895, becoming the Crossley telescope at that observatory.
- The 60-inch reflector
In 1885 Common embarked on building a 60-inch (152 cm) Newtonian reflecting telescope. He chose to buy the raw glass blank and do the grinding and polishing himself. The first mirror he made performed poorly, showing an elliptical deformation of the stars, causing him to fabricate a second mirror in 1890. After a near fall from the high staging needed to reach the Newtonian focus of the telescope Common decided to convert the telescope to a Cassegrain configuration for safer use. To avoid having to bore a hole in the 60 inch primary mirror he mounted a diagonal flat mirror just in front of it to bring the image out to a focus at the lower side of the telescope. He was not satisfied with how this configuration worked and that, combined with his attention being diverted to other projects and the ever more light polluted skies west of London, meant the telescope fell into disuse. After Common’s death the telescope with its two 60 inch mirrors and other secondary optics was purchased from his estate and installed at the Harvard College Observatory.[2] In the 1933[3] the primary mirror was re-figured and a new mount built. It was then set up as the 1.5 meter Boyden-UFS reflector (also called the "60 inch Rockefeller") at Boyden Observatory in South Africa.
[edit] Other projects
Andrew Ainslie Common experience with optical fabrication lead him to work on gun-sights and telescopes for the army and navy. He also pioneered techniques to produce large optical flat mirrors.
[edit] Selected honours and awards
- Fellow of the Royal Society (1885)
- President of the Royal Astronomical Society (1895 – 1896)
[edit] See also
[edit] Further reading
- "Obituary Notices : Fellows :- Common, Andrew Ainslie". Monthly Notices of the Royal Astronomical Society 64: 274–278. 1904. Bibcode 1904MNRAS..64..274..
- Turner, H. H. (1903). "Obituary: Andrew Ainslie Common". The Observatory 26: 304–308. Bibcode 1903Obs....26..304T.
- Gingerich, Owen (1980). "The First Photograph of a Nebula". Sky and Telescope (November): 364–366.
[edit] External links
[edit] References
- ^ History of astronomy: an encyclopedia by John Lankford, page 512
- ^ "Waywiser, the online database of Harvard's Collection of Historical Scientific Instruments", Object Name: 15.875-inch secondary mirror for 60-inch reflecting telescope Inventory Number: 1996-1-0684 Classification: Mirror
- ^ King, Henry (2003). The History of the Telescope. Dover Publications. pp. 295. ISBN 0486432653.
