The discovery of the Great Comet of 1861 by John Tebbutt

The great comet of 1861

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

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.

Tebbutt marine telescope

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.

4 responses to “The discovery of the Great Comet of 1861 by John Tebbutt

  • I never cease to be amazed by the feats/performances of people in the approx. period 1750 to 1900. With so little equipment and virtually no resources they achieved so much. Sadly they are so often overlooked because they were “uneducated’ and had no computer on which to create endless “models”. Without the latter there are no grants are there.

  • Tebbutt will be remembered again. After the apparition of the comet had passed, the observations were reanalysed, and an periodic orbit was determined. We have found that this comet was highly inclined at about 85 degrees, and from all the positional data, the orbit is calculated to have a long period of about 408 years.
    The comet can be as close to the sun as 0.82 A.U., and will travel more than 109 A.U. from the Sun.
    When 2011 clicks over in May, this discovery will mark its 150th anniversary. If the 408 year period is true, the the comet is still moving away from the Sun, and will only start its return journey in 2065!
    Tebbutt’s Great Comet is expected to return again sometime in 2269.

    Certainly after this spectacular event is observed again, Tebbutt’s astronomical reputation, both in Australia and abroad will remain permanently secure. Of that I have no doubt! Dr. Lomb is quite right that he was “Australia’s foremost amateur astronomer.”

    Note: Tebbutt found another bright comet on 13 May 1881 exactly twenty years later!. Although Comet Tebbutt 1881 III was not as spectacular, it showed his dedication and persistence as a serious amateur astronomer.

  • Readers of this post may be interested to know that there are other letters to John Tebbutt and also referring to him among the posts in this blog. You can find these by searching for ‘Tebbutt’ in the search field at top right.

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