C/1823 Y1
Coma and twin tails of the Great Comet of 1823.
Discovered byNell de Bréauté
Discovery dateDecember 29, 1823
1823; Great Comet of 1823, Comet De Bréauté-Pons
Orbital characteristics
Epoch1824 Feb 15.0(UT)[1]
Perihelion0.226742 AU
Inclination103.8194 °
Last perihelion1823 Dec 09.93400000

The Great Comet of 1823, also designated C/1823 Y1 or Comet De Bréauté-Pons, was a bright comet visible in the last month of 1823 and the first months of 1824.

It was independently discovered by Nell de Bréauté at Dieppe on December 29, by Jean-Louis Pons on the morning of December 30, and by Wilhelm von Biela at Prague on the same morning.[2] It was already visible to the naked eye when discovered: Pons initially thought he was seeing smoke from a chimney rising over a hill, but continued observing when he noticed it did not change appearance. He was later to note that the comet was, puzzlingly, more easily visible to the naked eye than through a telescope.[3]

The comet was particularly known at the time for exhibiting two tails, one pointing away from the Sun and the other (termed an "anomalous tail" by Harding and Olbers)[4] pointing towards it.

Caroline Herschel recorded an observation of the comet on January 31, 1824 as the last entry in her observing book.[5]

Pons was also the last astronomer to detect the comet, on April 1, 1824.


  1. ^ Alan Chamberlin. "JPL Small-Body Database Browser". Ssd.jpl.nasa.gov. Retrieved 2016-01-20.
  2. ^ Kronk, G. Cometography: volume 2, CUP, 2003, pp.62-3. Some sources give December 24 as its discovery date, but this may be an error.
  3. ^ Kronk, p.64
  4. ^ Sekanina, Z.; Hanner, M. S.; Jessberger, E. K.; Fomenkova, M. N. (2001). "Cometary Dust". In Grun, E.; Gustafson, B. A. S.; Dermott, S. F.; Fechtig, H. (eds.). Interplanetary Dust. Heidelberg: Springer. p. 112. ISBN 3-540-42067-3.
  5. ^ Olson, Roberta J. M.; Pasachoff, Jay M. (2012). "The Comets of Caroline Herschel (1750–1848), Sleuth of the Skies at Slough". Culture and Cosmos. 16 (1–2): 9. arXiv:1212.0809. Bibcode:2012arXiv1212.0809O.