440P/Kobayashi (0440P)


Type: Periodic Perihelion date: 29 March 2022 Perihelion distance (q): 2.1 Aphelion distance (Q) : 15.1 Period (years): 25.2 Eccentricity (e): 0.76 Inclination (i): 12.3 JPL orbit diagram COBS lightcurve 440P/Kobayashi = 1997 B1 = 2021 W2 This object was initially reported to the IAU by S Nakano as an asteroid discovered by Takao Kobayashi on 31 January 1997, but subsequent observations showed that it was in a cometary orbit and further observations by W Offutt showed it to have a coma and tail. The nuclear magnitude of the comet was around 17, but visual observations may put it brighter. This is the first amateur CCD discovery of a comet and is also the faintest amateur discovery and shows that the field is not lost to the professional search teams. The Purple Mountain Observatory discovered a potential 20th magnitude NEO at their XuYi station with their 1.04m Schmidt on 11 January 2022. The MPC identified this as a return of 1997 B1 and then found isolated tracklets from 29 November 2021 taken with the Bok 2.25m reflector at Kitt Peak. PanSTARRS then found the comet in images taken earlier in November. This sequence suggests that the comet should have been designated 2022 A2 as this was the discovery. The comet was some 0.5 degrees from the prediction based on observations in 1997. Observations (VEMag = visual equivalent magnitude) Date 10x10 mag Error VEmag Coma ' 26-Apr-22 18.23 0.08 18.3 0.4