Electronic Telegram No. 5197 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 U5 = P/2013 W3 (PANSTARRS) R. Weryk, Department of Physics and Astronomy, University of Western Ontario, reports the discovery of another comet in images obtained with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala, Hawaii, on Oct. 28 (discovery observations tabulated below). 2022 UT R.A. (2000) Decl. Mag. Oct. 28.59153 8 19 10.59 +35 19 32.4 21.2 28.60354 8 19 11.35 +35 19 36.7 21.0 28.61556 8 19 12.16 +35 19 41.1 20.9 28.62759 8 19 12.96 +35 19 45.4 21.4 Weryk also identified thirteen images of the comet (as an apparently asteroidal object then) obtained on five nights during 2013 Nov. 25-2014 Jan. 6 obtained with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala, with the following magnitudes: 2013 Nov. 25.5 UT, 22.5; Nov. 27.51-27.61, 20.7-21.8 (already in the Minor Planet Center's "isolated tracklet file"); Dec. 5.4, 20.3-20.4; Dec. 7.5, 19.8; 2014 Jan. 6.3, 21.1. The comet also appears on pre-discovery Pan-STARRS1 images from 2021 Aug. 5.6 (mag 22.2-23.0) and 2021 Nov. 6.3 (mag 21.7-21.9), 7.4 (mag 21.5), and 23.2 (mag 21.4-22.1), as well as on Pan-STARRS2 images from 2021 Sept. 8.5 (mag 22.0-22.7), 2021 Sept. 25.5 (mag 22.0), 2021 Sept. 30.5 (mag 21.7-22.0), 2021 Oct. 26.4 and 30.3 (mag 21.8-22.3), and 2022 Sept. 16.6 (mag 20.4). Weryk adds that three 60-s gri-band follow-up images obtained by R. Wainscoat and himself on 2022 Nov. 23.5 UT with the 3.6-m Canada-France-Hawaii Telescope at Mauna Kea (queue observer H. Januszewski; coordinator E. Bertin) show a condensed head of size 0".9 (full-width-at-half-maximum) in 0".6 seeing with a very clear tail 8" long, the center of which is towards p.a. 270 degrees. After the comet was posted on the MPC's PCCP webpage, H. Sato (Bunkyo-ku, Tokyo, Japan) reported that sixteen 120-s CCD exposures taken remotely with a 0.43-m f/6.8 astrograph located at Mayhill, NM, USA, on 2022 Nov. 2.5 UT show a strongly condensed object with an outer coma 6" in diameter and a 10" tail toward p.a. 270 degrees; the magnitude was 20.1 as measured within a circular aperture of radius 5".7. The available astrometry appears on MPEC 2022-W234. The following linked orbital elements by S. Nakano (Central Bureau) are from 75 observations spanning 2013-2022 (mean residual 0".2). There have been no recent close approaches to major planets, and Nakano was unable to find earlier observations in archival data files. Epoch = 2013 Nov. 4.0 TT T = 2013 Nov. 5.99762 TT Peri. = 19.15696 e = 0.3520967 Node = 55.34006 2000.0 q = 2.7622170 AU Incl. = 19.84136 a = 4.2633165 AU n = 0.11196511 P = 8.80 years Epoch = 2022 Aug. 9.0 TT T = 2022 July 25.90881 TT Peri. = 19.97038 e = 0.3612116 Node = 54.59015 2000.0 q = 2.6856280 AU Incl. = 19.81307 a = 4.2042528 AU n = 0.11433280 P = 8.62 years Epoch = 2031 Apr. 4.0 TT T = 2031 Mar. 21.34137 TT Peri. = 20.07773 e = 0.3599924 Node = 54.54690 2000.0 q = 2.7016869 AU Incl. = 19.78583 a = 4.2213358 AU n = 0.11363948 P = 8.67 years Epoch = 2039 Nov. 28.0 TT T = 2039 Nov. 16.48598 TT Peri. = 20.20543 e = 0.3609546 Node = 54.46968 2000.0 q = 2.6880251 AU Incl. = 19.80312 a = 4.2063134 AU n = 0.11424880 P = 8.63 years Epoch = 2048 July 23.0 TT T = 2048 Aug. 1.69067 TT Peri. = 20.67283 e = 0.3563288 Node = 54.36778 2000.0 q = 2.7409231 AU Incl. = 19.73042 a = 4.2582658 AU n = 0.11216437 P = 8.79 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 14.0 and 2.5n = 10 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 10 28 08 18.51 +35 16.1 2.474 2.750 95.3 21.1 20.4 2022 11 07 08 28.71 +36 19.0 2.365 2.764 103.1 20.4 20.3 2022 11 17 08 36.69 +37 32.7 2.263 2.779 111.3 19.4 20.2 2022 11 27 08 42.08 +38 57.3 2.171 2.795 119.8 17.8 20.1 2022 12 07 08 44.53 +40 31.1 2.092 2.813 128.5 15.9 20.1 2022 12 17 08 43.84 +42 09.9 2.030 2.832 137.1 13.7 20.1 2022 12 27 08 39.94 +43 47.1 1.989 2.851 145.0 11.4 20.0 2023 01 06 08 33.20 +45 14.1 1.971 2.872 151.1 9.5 20.1 2023 01 16 08 24.42 +46 22.4 1.979 2.894 153.7 8.7 20.1 2023 01 26 08 14.79 +47 05.6 2.013 2.917 151.6 9.2 20.2 2023 02 05 08 05.77 +47 21.1 2.071 2.940 145.9 10.8 20.3 2023 02 15 07 58.57 +47 10.9 2.153 2.965 138.4 12.8 20.4 2023 02 25 07 54.03 +46 39.1 2.255 2.990 130.1 14.7 20.5 2023 03 07 07 52.52 +45 51.2 2.373 3.016 121.8 16.2 20.7 2023 03 17 07 54.00 +44 52.1 2.505 3.042 113.5 17.4 20.8 2023 03 27 07 58.19 +43 45.4 2.647 3.070 105.6 18.2 21.0 2023 04 06 08 04.71 +42 33.7 2.796 3.098 98.0 18.7 21.1 2023 04 16 08 13.14 +41 18.4 2.949 3.126 90.7 18.7 21.3 2023 04 26 08 23.11 +40 00.5 3.103 3.155 83.7 18.5 21.4 2023 05 06 08 34.26 +38 40.3 3.257 3.184 76.9 18.0 21.6 2023 05 16 08 46.31 +37 18.1 3.409 3.214 70.4 17.2 21.7 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 November 28 (CBET 5197) Daniel W. E. Green