Electronic Telegram No. 5174 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 R4 (PANSTARRS) R. Weryk, Department of Physics and Astronomy, University of Western Ontario, reports the discovery of another comet in four 45-s w-band survey images obtained with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala, Hawaii, on Sept. 2 (discovery observations tabulated below). The condensed coma was measured to be 1".4 across (full-width-at-half-maximum) in 1".0 seeing, with a tail about 5" long in p.a. 280 degrees. 2022 UT R.A. (2000) Decl. Mag. Sept. 2.57664 4 29 45.92 + 5 22 12.5 21.3 2.58973 4 29 47.09 + 5 22 04.4 21.1 2.60269 4 29 48.27 + 5 21 56.6 21.0 2.62318 4 29 50.13 + 5 21 43.8 21.0 Follow-up observations were arranged by R. Wainscoat and Weryk on Sept. 3.6 UT with the 3.6-m Canada-France-Hawaii Telescope at Mauna Kea (queue observer C. Cunningham; queue coordinator H. Flewelling); three 60-s gri-band images show this to be definitely a comet, with a condensed coma of size 1".0 (FWHM) in 0".67 seeing and a clear tail 5" long in p.a. 280 degrees. Weryk adds that two 60-s w-band follow-up Pan-STARRS1 images taken on Sept. 22.58 show a condensed coma of size 1".4 (FWHM) in 1".0 seeing, again with a tail about 5" long in p.a. 280 degrees. Twenty-four stacked 60-s CCD exposures taken remotely by H. Sato (Bunkyo-ku, Tokyo, Japan) on Sept. 23.44-23.45 with a 0.43-m f/6.8 astrograph at Mayhill, NM, USA, showed only a stellar appearance; the magnitude was 20.1 as measured within a circular aperture of radius 5".7. The available astrometry appears on MPEC 2022-T87. The following elliptical orbital elements by S. Nakano (Central Bureau) are from 33 observations spanning Sept. 2-Oct. 4 (mean residual 0".3). No other observations were found in a search of archival astrometry, but there the comet may have passed about 0.55 AU from Jupiter in 1957. T = 2022 July 10.37155 TT Peri. = 197.42620 e = 0.4903859 Node = 176.62143 2000.0 q = 1.9554673 AU Incl. = 21.02095 a = 3.8371530 AU n = 0.13112648 P = 7.516 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 16.0 and 2.5n = 10 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 09 18 04 50.72 +02 24.3 1.577 2.044 102.4 28.7 20.1 2022 09 28 05 00.92 +00 11.2 1.515 2.070 108.9 27.3 20.1 2022 10 08 05 08.06 -02 10.7 1.461 2.099 115.8 25.4 20.0 2022 10 18 05 11.91 -04 34.8 1.417 2.130 123.0 23.1 20.0 2022 10 28 05 12.37 -06 53.1 1.386 2.164 130.1 20.6 20.1 2022 11 07 05 09.65 -08 55.3 1.371 2.200 136.8 18.0 20.1 2022 11 17 05 04.29 -10 31.5 1.373 2.238 142.2 15.7 20.2 2022 11 27 04 57.18 -11 33.3 1.395 2.278 145.4 14.2 20.3 2022 12 07 04 49.50 -11 55.9 1.439 2.319 145.5 13.9 20.4 2022 12 17 04 42.43 -11 40.1 1.504 2.362 142.6 14.7 20.6 2022 12 27 04 36.94 -10 50.4 1.588 2.406 137.3 16.1 20.8 2023 01 06 04 33.68 -09 34.5 1.692 2.451 130.9 17.7 21.0 2023 01 16 04 32.92 -08 01.0 1.812 2.497 123.8 19.1 21.3 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 October 6 (CBET 5174) Daniel W. E. Green