Electronic Telegram No. 5196 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 W1 (RANKIN) David Rankin, Lunar and Planetary Laboratory, University of Arizona, reports his discovery of another comet on images taken on Nov. 18 (discovery observations tabulated below) with the Mt. Lemmon Survey's 1.5-m reflector, noting the object to be condensed with an elongation (possible tail) toward p.a. 270 degrees. 2022 UT R.A. (2000) Decl. Mag. Observer Nov. 18.25822 4 43 06.52 +31 41 13.5 19.5 Rankin 18.26351 4 43 06.33 +31 41 14.7 19.8 " 18.26881 4 43 06.11 +31 41 16.2 19.4 " 18.27410 4 43 05.89 +31 41 16.9 19.6 " 18.38221 4 43 01.56 +31 41 36.4 19.5 " 18.39058 4 43 01.21 +31 41 38.1 19.7 " 18.39845 4 43 00.85 +31 41 40.4 19.7 " Previous unlinked Mt. Lemmon observations of this object from Sept. 24.5 UT (mag 20.6-21.0), Oct. 21.4 (mag 20.0-20.4), and Nov. 5.3 (mag 19.7-20.5) were later found in the Minor Planet Center's "isolated tracklet file". After the comet was posted to the MPC's PCCP, other CCD astrometrists have also commented on the cometary appearance. Fifty-eight 60-s CCD exposures taken on Nov. 19.2 UT by L. Buzzi (Varese, Italy) with a 0.84-m f/3.5 reflector (measured by A. Aletti and Buzzi) show a moderately condensed coma 8" wide of mag 19.4 with a hint of a faint tail in p.a. around 270 degrees. CCD exposures taken on Nov. 20.94-20.96 by D. Buczynski (Portmahomack, Tain, Scotland) with a 0.35-m f/6 Schmidt-Cassegrain reflector show a central condensed head surrounded by a faint diffuse coma 5" in diameter with an extension or tail 7" long toward p.a. 243 degrees. The available astrometry appears on MPEC 2022-W159. The following 2-body elliptical orbital elements by S. Nakano (Central Bureau) are from 62 observations spanning 2022 Sept. 24-Nov. 22. These suggest that the comet may have passed about 1.10 AU from Jupiter in 1968 Feb. and 0.07 AU from Saturn in 1954. No earlier archival observations were found. T = 2022 Sept.15.75487 TT Peri. = 17.79299 e = 0.5166161 Node = 38.81512 2000.0 q = 3.3677240 AU Incl. = 13.46549 a = 6.9669766 AU n = 0.05359664 P = 18.39 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 12.5 and 2.5n = 10 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 10 28 04 53.18 +30 19.5 2.574 3.380 138.1 11.3 19.8 2022 11 07 04 49.44 +31 01.5 2.502 3.386 148.4 8.8 19.8 2022 11 17 04 43.91 +31 37.3 2.454 3.394 158.6 6.1 19.8 2022 11 27 04 37.13 +32 04.8 2.433 3.403 167.4 3.6 19.7 2022 12 07 04 29.89 +32 23.2 2.441 3.413 168.9 3.2 19.8 2022 12 17 04 23.06 +32 32.9 2.477 3.424 161.3 5.3 19.8 2022 12 27 04 17.40 +32 35.6 2.542 3.437 151.3 7.9 19.9 2023 01 06 04 13.53 +32 34.0 2.632 3.451 140.9 10.4 20.0 2023 01 16 04 11.80 +32 30.8 2.743 3.466 130.8 12.4 20.1 2023 01 26 04 12.36 +32 28.1 2.871 3.482 121.0 14.0 20.2 2023 02 05 04 15.16 +32 27.5 3.014 3.500 111.7 15.2 20.3 2023 02 15 04 20.05 +32 29.5 3.165 3.518 102.8 15.9 20.5 2023 02 25 04 26.84 +32 34.2 3.323 3.538 94.3 16.2 20.6 2023 03 07 04 35.30 +32 41.0 3.483 3.559 86.2 16.2 20.7 2023 03 17 04 45.19 +32 49.1 3.644 3.580 78.5 15.8 20.8 2023 03 27 04 56.31 +32 57.7 3.801 3.603 71.0 15.2 21.0 2023 04 06 05 08.48 +33 05.8 3.954 3.627 63.9 14.3 21.1 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 November 24 (CBET 5196) Daniel W. E. Green