Title: Detection of Coma Activity of the ACO/Quasi-Hilda Object, 212P/2000YN30 Authors: Y.-C. Cheng, W.-H. Ip
The quasi-Hilda object, 212P/2000YN30 with a cometary-like orbit, was found to display a dust tail structure between January and March, 2009. From orbital calculations, it is shown that this object could have been an active comet in its past history before being transported to the current orbital configuration in quasi-stable 3:2 resonance with Jupiter.
An apparent asteroidal object discovered by the NEAT survey (the discovery observation tabulated below was originally assigned the designation 2000 YN 30 and published on MPO 24160) was recovered a few months ago with the 0.9-m Spacewatch reflector at Kitt Peak (recovery observation also tabulated below; cf. MPEC 2008-V41 and MPO 263011) but only recently noted to show cometary activity. A. R. Gibbs reports that four co-added 60-s unfiltered CCD exposures taken on 2009 Jan. 2.53 with the Catalina 0.68-m Schmidt telescope show a compact coma 7" across with a narrow 35" tail in p.a. 285 deg. Y. C. Cheng and H. Y. Hsiao, Institute of Astronomy, National Central University, Jhongli, Taiwan, report that three 300-s R-band images obtained on Jan. 2.8 with the Lulin 1-m telescope show total mag 18.2-18.4 and a tail < 20" long in p.a. 290 deg. J. V. Scotti writes that fifteen co-added exposures with the Spacewatch 1.8-m reflector on Jan. 7.4 show an 8" coma and a narrow tail extending at least 2'.2 in p.a. 283 deg; the tail's width expands with distance from the nuclear condensation from about 8" to 12" as it fades.
The following orbital elements by B. G. Marsden, Smithsonian Astrophysical Observatory, from 69 observations, 2000-2009 (mean residual 0".6), appear on MPC 64768 (with new observations on MPC 64748-64749). The permanent designation 212P has been assigned to this comet.
Epoch = 2008 Nov. 30.0 TT T = 2008 Dec. 3.2698 TT Peri. = 15.0488 e = 0.578876 Node = 98.9290 2000.0 q = 1.654465 AU Incl. = 22.3979 a = 3.928686 AU n = 0.1265707 P = 7.79 years