28P/Neujmin 1

Past, Present, and Future Orbits by Kazuo Kinoshita

Copyright © 1913 Astronomische Nachrichten This drawing was made by E. E. Barnard (Yerkes Observatory, Wisconsin, USA) on 1913 September 10.30, while viewing the comet with the 40-inch refractor. He at first thought the star in the center of the drawing was involved in the north preceding side of the comet's coma, but after a few minutes he realized the "star" was actually the comet's nucleus. This is the reason the comet was originally announced as a minor planet. South is up in the image and the diameter of the field is 5.5 arc minutes. Discovery      G. N. Neujmin (Simeis Observatory, Crimea, Ukraine) discovered this object on a photograph exposed on 1913 September 3.98, during a routine search for minor planets. The object was stellar and of magnitude 10.0. It was announced by Neujmin as a new minor planet. Kudrewisch (Pulkovo Observatory, Saint Petersburg, Russia) photographically confirmed the new object on September 5.91 and gave the magnitude as 10.8. On September 7, J. O. Backlund (Pulkovo Observatory) announced that Neujmin's minor planet was actually a comet, while K. Graff (Hamburg Observatory, Bergedorf, Germany) came to the same conclusion when he detected a short tail on September 7.10. Historical Highlights The Orbit: The first parabolic orbits were based on three positions obtained on September 7 and 8. C. W. L. M. Ebell determined the perihelion date as 1913 July 23.04, while S. Einarsson and S. B. Nicholson determined it as 1913 October 3.88. Based on the orbit of Einarsson and Nicholson, A. O. Leuschner noted that a parabola was unsatisfactory and that a period of 17.44 years fit best. Elliptical orbits were calculated shortly thereafter with periods ranging from 9 to 25 years. The period was eventually established as 17.76 years. Apparition of 1913 (discovery): At the time of discovery, this comet was about two weeks passed perihelion and less than two days passed its closest distance from Earth. Many observers were then estimating the magnitude as between 11 and 11.5. Many reported the comet as completely stellar in appearance, while some noted a faint trace of nebulosity toward the southeast side of the nucleus. Although the comet faded during the days and weeks that followed, T. Banachiewicz (Engelhardt Observatory, Kasan, Russia), Graff, and G. van Biesbroeck (Uccle, Belgium) noted some variations in the brightness of the nucleus. The comet was last detected on a photographic plate exposed by R. Schorr (Hamburg Observatory, Bergedorf, Germany) on December 31. The magnitude was then given as 15. Close approaches to planets: During the 19th and 20th centuries, this comet made two close approaches to Earth and two close approaches to Saturn. There will be one close approach to Earth during the 21st century. (From the orbital work of Kazuo Kinoshita) 0.79 AU from Saturn on 1892 February 10 decreased perihelion distance from 1.55 AU to 1.52 AU decreased orbital period from 17.72 to 17.54 years 0.55 AU from Earth on 1913 September 2 (contributed to comet's discovery) 0.83 AU from Saturn on 1980 June 7 increased perihelion distance from 1.54 AU to 1.55 AU increased orbital period from 17.93 to 18.21 years 0.87 AU from Earth on 1984 August 10 0.79 AU from Earth on 2039 September 11 cometography.com  Current Comets  |  Periodic  |  Sungrazers  |  Links  |  Comet Information Meteor Showers Online Media Inquiries