98P/Takamizawa (0098P)


Type: Periodic Perihelion date: 4 January 2021 Perihelion distance (q): 1.7 Aphelion distance (Q) : 5.9 Period (years): 7.4 Eccentricity (e): 0.56 Inclination (i): 10.6 JPL orbit diagram COBS lightcurve Kesao Takamizawa (Japan) discovered this comet on 30 July 1984 in Capricornus. He estimated the magnitude as 10 and said the comet was 2 arc minutes across. The comet was confirmed by K. Saito (Tokyo Observatory, Dodaira Station, Japan) on 31 July and C. S. Morris and A. Hale (Whitaker Peak, California, USA) on 1 August. Saito estimated the magnitude as 10, while Morris and Hale determined it as 9.5 and 9.3, respectively. Morris added that a faint tail extended 4-5 arc minutes toward the west. T. Seki (Geisei, Japan) found a prediscovery image on a photographic plate exposed on 26 July. He estimated the magnitude of the trailed image as 17. P. Wild (Zimmerwald, Switzerland) found prediscovery images on plates exposed on 6 and 8 July. Wild said the 8 July image had been noticed at the time because of its "bright asymmetric coma and fanshaped tail," but it was rejected as a plate defect when a similar image could not be found on the 6 July plate. An image was found on the 6 July plate after the first orbit had been computed. The image consisted of a "distinct nucleus" of magnitude 17 situated within a "very tenuous coma." The comet's total magnitude was estimated as 16 on the 6th and 13 on the 8th. The first orbit was published on 3 August. Brian G. Marsden (Central Bureau for Astronomical Telegrams) computed a parabolic orbit using 8 positions obtained during the period of 31 July to 2 August. It indicated a perihelion date of 5 May 1984 and a perihelion distance of 1.56 AU. He added, "It is quite probable that the comet is a short-period one." On 7 August, International Astronomical Union Circular number 3970 said S. Nakano (Tokyo, Japan) and Marsden had independently confirmed the comet moved in a short-period orbit. Perihelion was expected between 23 and 26 May at a distance of about 1.57 AU. The calculations indicated the orbital period was between 6.49 and 7.23 years. After the prediscovery images were announced, Marsden published a new orbit on 20 August, which indicated a perihelion date of 24 May 1984 and an orbital period of 7.26 years. The comet faded after its discovery, having already passed both it perihelion and closest distance from Earth. By the end of August it was near magnitude 10.5 and it was near magnitude 12 by the end of September. The comet was last seen on 25 November. The comet was next recovered on 17 February 1991 by James V. Scotti (University of Arizona, USA) with the Spacewatch telescope. The total magnitude was then determined as between 19.6 and 19.9. Scotti said there was a tail extending about 30 arc seconds toward PA 285-290 degrees. His precise positions indicated the prediction required a correction of -0.5 day. Although the comet was expected to reach magnitude 16 during July and August, observations by amateur astronomers during August revealed the comet had reached magnitude 14. The comet was kept under observation until 13 September. The comet next returned to perihelion on 7 November 1998. This was not a favorable apparition, with only 13 observations being made during the period of 2 March to 19 June 1998. The brightest reported magnitude was 18.7. Observations (VEMag = visual equivalent magnitude) Date 10x10 mag Error VEmag Coma ' 15-Mar-13 03-Apr-13 20.18 0.13 20.2 0.1 15-Apr-13 19.31 0.04 07-Jun-13 17.98 0.11 17.8 0.2 24-Jun-13 16.84 0.07 15.6 0.2 05-Jul-13 16.83 0.05 16.0 0.4 15-Jul-13 16.19 0.06 15.2 0.2 28-Jul-13 15.78 0.02 14.5 0.4 07-Aug-13 15.95 0.03 14.7 0.4 19-Aug-13 15.96 0.06 14.4 0.3 30-Aug-13 16.35 0.03 15.3 0.3 18-Sep-13 16.15 0.06 15.8 0.3 11-Nov-13 17.61 0.15 16.9 0.2