Electronic Telegram No. 5194 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 U4 (BOK) An apparently asteroidal object discovered on Oct. 26 with the 2.25-m Bok reflector at Kitt Peak (as part of the "Bok NEO Survey" and reported to the Minor Planet Center as a near-earth-object "candidate"; discovery observations tabulated below) has been found to show cometary appearance elsewhere. 2022 UT R.A. (2000) Decl. Mag. Oct. 26.48253 11 20 23.36 +23 33 41.0 20.2 26.48745 11 20 23.73 +23 33 41.6 20.3 26.49236 11 20 24.07 +23 33 42.0 20.0 26.49726 11 20 24.44 +23 33 42.9 20.0 G. J. Leonard, University of Arizona, reported that CCD observations obtained on Oct. 27.5 UT with the Steward Observatory 1-m reflector at Mt. Lemmon show a small, strongly condensed coma of siz about 6" and magnitude 19.9-20.1 with a possible short tail or asymmetry about 3" long toward p.a. 300 degrees. After the comet was posted to the MPC's PCCP webpage, R. Weryk (Department of Physics and Astronomy, University of Western Ontario) found many pre-discovery images of the comet in exposures obtained with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala from 2022 Jan. 7.45 UT (at mag 22.7) to Mar. 7.24 (mag 23.2), including on seven dates in between (the brightest reported magnitude being 21.9) -- with no cometary appearance detected. Twelve stacked 60-s exposures taken remotely by H. Sato (Bunkyo-ku, Tokyo, Japan) with a 0.61-m f/6.5 astrograph located at the Sierra Remote Observatory near Auberry, CA, USA, on Oct. 28.54 UT show only a stellar appearance; the magnitude was 19.8 as measured within a circular aperture of radius 3".8. CCD exposures taken by M. T. Read (University of Arizona) with the Spacewatch 0.9-m f/3 reflector at Kitt Peak on Nov. 16.5 in 2".6 seeing show a 10" tail in p.a. 330 degrees; the red magnitude of the object was measured to be 19.1-19.7. The available astrometry appears on MPEC 2022-W158. The following elliptical orbital elements by S. Nakano (Central Bureau) are from 69 observations spanning 2022 Jan. 7-Nov. 22 (mean residual 0".3), with corresponding original and future values of 1/a being +0.000019 and +0.000253 (+/- 0.000007) AU**-1, respectively. Epoch = 2023 Aug. 4.0 TT T = 2023 Aug. 3.67900 TT Peri. = 89.00938 e = 0.9991343 Node = 132.92639 2000.0 q = 2.8983508 AU Incl. = 52.03494 The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 10.0 and 2.5n = 10 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 10 28 11 22.24 +23 36.6 4.479 3.986 54.5 11.7 19.3 2022 11 07 11 34.41 +24 01.4 4.292 3.923 61.8 12.9 19.1 2022 11 17 11 46.53 +24 37.4 4.100 3.861 69.2 13.9 18.9 2022 11 27 11 58.49 +25 26.8 3.904 3.799 76.6 14.6 18.8 2022 12 07 12 10.22 +26 31.7 3.709 3.739 84.1 15.2 18.6 2022 12 17 12 21.60 +27 53.9 3.519 3.680 91.6 15.5 18.4 2022 12 27 12 32.50 +29 35.2 3.336 3.622 99.0 15.6 18.2 2023 01 06 12 42.73 +31 36.4 3.164 3.566 106.2 15.4 18.0 2023 01 16 12 52.11 +33 57.4 3.008 3.511 113.0 14.9 17.8 2023 01 26 13 00.40 +36 36.5 2.870 3.457 119.1 14.4 17.7 2023 02 05 13 07.32 +39 29.8 2.753 3.406 124.1 13.9 17.5 2023 02 15 13 12.62 +42 31.7 2.660 3.356 127.7 13.5 17.4 2023 02 25 13 16.03 +45 34.4 2.590 3.308 129.4 13.4 17.3 2023 03 07 13 17.39 +48 28.6 2.544 3.262 129.1 13.7 17.2 2023 03 17 13 16.71 +51 05.2 2.521 3.218 126.9 14.3 17.1 2023 03 27 13 14.21 +53 15.9 2.517 3.176 123.4 15.2 17.0 2023 04 06 13 10.45 +54 54.3 2.529 3.137 118.9 16.2 17.0 2023 04 16 13 06.24 +55 57.3 2.555 3.101 114.0 17.2 17.0 2023 04 26 13 02.50 +56 24.2 2.590 3.067 108.9 18.1 16.9 2023 05 06 13 00.13 +56 16.8 2.632 3.036 103.9 18.8 16.9 2023 05 16 12 59.75 +55 38.7 2.678 3.007 99.0 19.4 16.9 2023 05 26 13 01.70 +54 33.6 2.726 2.982 94.5 19.8 16.9 2023 06 05 13 06.07 +53 05.5 2.775 2.960 90.3 20.0 16.9 2023 06 15 13 12.71 +51 17.8 2.824 2.941 86.5 20.2 16.9 2023 06 25 13 21.39 +49 13.6 2.872 2.926 82.9 20.2 17.0 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 5194) Daniel W. E. Green