The discovery of the Great Comet of 1861 by John Tebbutt
The Great Comet of 1861 on 30 June 1861, in Descriptive Astronomy by George Chambers, drawn by G Williams. Courtesy Sydney Observatory
On 13 May 1861 a young farmer at Windsor, a little town near Sydney, saw a fuzzy star. On checking his celestial charts he saw that there was no nebula listed for that position. Still, he could not be sure that it was a comet until he saw it move against the background stars. It took until the 21 May till he could detect sufficient movement to be almost certain. He then sent off a letter to the Rev. William Scott, the Government Astronomer at Sydney Observatory, as well as a letter to the Sydney Morning Herald. This letter was published in the paper on 25 May 1861, the young farmer’s 27th birthday.
John Tebbutt’s letter to the Sydney Morning Herald 25 May 1861, courtesy of the National Library of Australia.
While researching a talk I gave this morning (16 November 2010) to the Diurnals section of the Astronomical Society of Victoria I was pleased to be able to find the letter online from the National Library of Australia. John Tebbutt had the excellent habit of reporting his discoveries and observations to the general public by publishing them in the newspapers as well as in the astronomical journals.
The marine telescope with which John Tebbutt discovered the Great Comet of 1861. It is still at Windsor Observatory. Image and copyright Nick Lomb ©, all rights reserved
In those days there was no quick communication between Australia and the rest of the world so that when the comet became visible in the northern hemisphere on 29 June 1861, it was a complete surprise to the astronomers in Britain and elsewhere. In his memoirs Tebbutt quotes from Descriptive Astronomy by George F Chambers, 1867 edition:
Few comets created greater sensation than the Great Comet of 1861. It was discovered by Mr. J. Tebbutt, an amateur observer in New South Wales, on May 13, prior to its perihelion passage, which took place on June 11. Passing from the southern hemisphere into the northern it became visible in this country (England) on June 29, though it was not generally seen until the next evening.
The discovery of this comet was a great way for young John Tebbutt to introduce himself to astronomers the world over. Over the next 40 years or so, he put out such a prodigious stream of high quality observations of comets, minor planets, variable stars, eclipses and transits that his reputation continually increased. At the time his one-man observatory at Windsor was regarded as the equal of the government observatories in Sydney and Melbourne. Today he is rightly judged as having been Australia’s foremost amateur astronomer.