Electronic Telegram No. 5182 Central Bureau for Astronomical Telegrams Mailing address: Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network COMET C/2022 QE_78 (ATLAS) An apparently asteroidal object discovered on CCD images taken on Aug. 27 UT with a 0.5-m f/2 Schmidt reflector at Rio Hurtado, Chile, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program has been found to show cometary appearance by CCD astrometrists elsewhere. The discovery observations are tabulated below, (as first published on MPEC 2022-R154, when it was given the minor-planet designation 2022 QE_78). 2022 UT R.A. (2000) Decl. Mag. Aug. 27.32319 3 47 21.51 -18 12 43.0 19.4 27.32598 3 47 21.57 -18 12 44.4 19.4 27.33027 3 47 21.56 -18 12 44.6 19.0 27.35358 3 47 21.67 -18 12 49.6 19.6 R. Weryk, Department of Physics and Astronomy, University of Western Ontario, reports that three 45-s w-band survey images obtained on Sept. 7.6 UT with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala, Hawaii, show a condensed coma of mag 19.3 and size 1".75 (full-width-at-half-maximum) in 1".2 seeing, with a 2" tail in p.a. 280 degrees. He adds that four 45-s w-band exposures taken on Sept. 24.6 with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala show a condensed head of mag 19.7 with size 1".7 (FWHM) in 1".0 seeing and a 2" tail in p.a. 280 degrees. Four 45-s w-band Pan-STARRS2 survey images taken on Oct. 1.53-1.56 in 1".4 seeing show a condensed coma of size 2".0 (FWHM) and a 2" tail in p.a. 280 degrees. Four 45-s i-band Pan-STARRS2 survey images taken on Oct. 15.5 show a condensed coma of mag 19.2-19.3 with size 1".9 (FWHM) in 1".4 seeing, and again a 2" tail in p.a. 280 deg. Two 45-s w-band Pan-STARRS1 images taken on Oct. 19.48 in 1".5 seeing show a condensed head of size 2".0 (FWHM) and mag 18.8 with a 2" tail in p.a. 280 degrees. Four 45-s w-band Pan-STARRS1 survey images taken on Oct. 20.5 in 1".2 seeing show a condensed coma of size 1".81 (FWHM) and a 2" tail in p.a. 280 degrees. Six stacked 120-s CCD exposures taken remotely by H. Sato (Bunkyo-ku, Tokyo, Japan) on Oct. 20.30 with a 0.51-m f/6.8 astrograph also located at Rio Hurtado show a strongly condensed, disk-like coma 7" in diameter and no tail; Sato suggests that the comet was in outburst, noting that the magnitude was 16.9 as measured within a circular aperture of radius 3".6. Additional astrometry appears on MPEC 2022-U218. The following orbital elements by S. Nakano (Central Bureau) are from 101 observations Aug. 27-Oct. 22 (mean residual 0".3), with corresponding original and future values of 1/a being -0.000128 and +0.001943 AU**-1, respectively (+/- 0.000191). The comet will pass 1.93 AU from Jupiter on 2025 Aug. 22 UT; after that passage and including other planetary perturbations, the comet will have a future semi- major axis of around 515 AU (period around 12k years). Epoch = 2025 Sept. 2.0 TT T = 2025 Sept.11.49427 TT Peri. = 0.63569 e = 1.0024353 Node = 119.87982 2000.0 q = 5.4733018 AU Incl. = 36.63482 The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 6.0 and 2.5n = 8 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 09 18 03 48.13 -19 20.6 8.823 9.325 117.2 5.5 18.5 2022 09 28 03 47.35 -19 52.3 8.676 9.274 124.0 5.1 18.4 2022 10 08 03 45.86 -20 22.3 8.546 9.223 130.2 4.7 18.4 2022 10 18 03 43.74 -20 48.8 8.436 9.172 135.3 4.4 18.3 2022 10 28 03 41.08 -21 10.4 8.348 9.121 138.9 4.1 18.3 2022 11 07 03 38.02 -21 25.6 8.284 9.070 140.4 4.0 18.3 2022 11 17 03 34.72 -21 33.3 8.244 9.019 139.6 4.1 18.2 2022 11 27 03 31.37 -21 32.6 8.228 8.968 136.4 4.4 18.2 2022 12 07 03 28.17 -21 23.2 8.235 8.918 131.5 4.7 18.2 2022 12 17 03 25.28 -21 05.1 8.263 8.867 125.2 5.2 18.2 2022 12 27 03 22.89 -20 39.0 8.310 8.817 118.2 5.6 18.2 2023 01 06 03 21.11 -20 05.5 8.372 8.766 110.6 6.0 18.2 2023 01 16 03 20.05 -19 25.9 8.445 8.716 102.8 6.3 18.2 2023 01 26 03 19.76 -18 41.3 8.527 8.666 94.9 6.5 18.2 2023 02 05 03 20.26 -17 53.0 8.612 8.616 86.9 6.6 18.2 2023 02 15 03 21.55 -17 02.5 8.697 8.566 79.1 6.5 18.2 2023 02 25 03 23.60 -16 10.7 8.778 8.516 71.5 6.3 18.2 2023 03 07 03 26.36 -15 18.8 8.852 8.466 64.1 6.1 18.2 2023 03 17 03 29.77 -14 27.8 8.916 8.416 57.0 5.7 18.2 2023 03 27 03 33.76 -13 38.4 8.968 8.367 50.3 5.3 18.1 2023 04 06 03 38.26 -12 51.6 9.005 8.317 44.2 4.8 18.1 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 October 24 (CBET 5182) Daniel W. E. Green