Electronic Telegram No. 5168 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 P/2022 R1 (PANSTARRS) R. Weryk, Department of Physics and Astronomy, University of Western Ontario, reports the discovery of another comet in images obtained on Sept. 1 with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala, Hawaii; he notes that four stacked 45-s w-band survey images show a condensed coma of size 1".95 (full-width-at-half-maximum) in 1".1 or better seeing, with a straight tail about 3" long in p.a. 270 degrees. The discovery observations are tabulated below. 2022 UT R.A. (2000) Decl. Mag. Sept. 1.35438 22 22 39.17 - 6 31 46.5 20.8 1.36585 22 22 38.83 - 6 31 49.4 20.9 1.37737 22 22 38.50 - 6 31 52.1 21.1 1.38889 22 22 38.15 - 6 31 54.9 21.0 1.49978 22 22 34.82 - 6 32 21.8 20.4 1.50042 22 22 34.81 - 6 32 21.9 20.8 After the comet was posted on the Minor Planet Center's PCCP webpage, other CCD astrometrists elsewhere also noted the cometary appearance. Eight stacked 120-s exposures taken remotely by H. Sato (Bunkyo-ku, Tokyo, Japan) on Sept. 2.3 UT with a 0.51-m f/6.8 astrograph located at Rio Hurtado, Chile, show a moderately condensed coma 8" in diameter with a hint of tail 12" long toward p.a. 295 degrees; the magnitude was 20.3 as measured within a circular aperture of radius 4".3. Eighty-nine stacked 60-s exposures taken remotely by A. Aletti, F. Bellini, L. Buzzi, and G. Galli on Sept. 3.0 with a 0.36-m f/8.4 reflector at Hakos, Namibia, show a softer aspect with respect to nearby stars (and full-width-at-half-maximum size for the apparent coma of 5".4 in 3".6 seeing); the magnitude was given as 20.5. The available astrometry appears on MPEC 2022-R124, including pre- discovery Pan-STARRS2 observations subsequently reported from 2022 June 23.6 UT (mag 21.8), July 20.5 (mag 21.3), and July 27.5 (mag 21.2-21.5) and also pre-discovery observations obtained with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala on Aug. 19.5 (mag 20.6-20.8). The following two-body orbital elements by S. Nakano (Central Bureau) are from 31 observations spanning 2022 June 23-Sept. 3 (mean residual 0".4); as the orbit depends awkwardly upon that single observations on June 23 (a month before the next available observations), the orbital period is necessarily uncertain by +/- 1 month or more. There is an indication that the comet passed 0.33 AU from Saturn on 2011 July. T = 2023 Oct. 13.59739 TT Peri. = 222.83354 e = 0.5019452 Node = 176.17239 2000.0 q = 3.5666580 AU Incl. = 7.40991 a = 7.1611756 AU n = 0.05143131 P = 19.16 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 12.0 and 2.5n = 8 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 08 09 22 33.27 -05 06.6 3.494 4.449 157.8 4.9 19.9 2022 08 19 22 29.01 -05 40.1 3.420 4.415 168.3 2.7 19.8 2022 08 29 22 24.28 -06 18.3 3.373 4.382 176.6 0.8 19.8 2022 09 08 22 19.48 -06 58.7 3.356 4.349 168.7 2.6 19.7 2022 09 18 22 15.05 -07 38.6 3.368 4.316 157.9 5.0 19.7 2022 09 28 22 11.39 -08 15.1 3.406 4.283 147.2 7.3 19.7 2022 10 08 22 08.84 -08 46.1 3.469 4.251 136.6 9.3 19.7 2022 10 18 22 07.63 -09 09.8 3.552 4.219 126.3 11.0 19.8 2022 10 28 22 07.89 -09 25.1 3.651 4.188 116.4 12.3 19.8 2022 11 07 22 09.69 -09 31.4 3.762 4.157 106.7 13.2 19.8 2022 11 17 22 12.97 -09 28.6 3.880 4.127 97.5 13.7 19.9 2022 11 27 22 17.65 -09 16.9 4.002 4.097 88.5 13.9 19.9 2022 12 07 22 23.63 -08 56.6 4.124 4.068 79.9 13.8 20.0 2022 12 17 22 30.75 -08 28.3 4.242 4.039 71.5 13.4 20.0 2022 12 27 22 38.88 -07 52.5 4.353 4.011 63.4 12.7 20.0 2023 01 06 22 47.89 -07 10.0 4.456 3.984 55.6 11.7 20.0 2023 01 16 22 57.65 -06 21.5 4.548 3.957 47.9 10.6 20.1 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 September 7 (CBET 5168) Daniel W. E. Green