Electronic Telegram No. 5218 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 T1 (LEMMON) An apparently asteroidal object discovered on 2022 Oct. 3 with the Mt. Lemmon Survey's 1.5-m reflector (and given the designation A/2022 T1 when published on MPEC 2022-W160; discovery observations tabulated below) has been found to be clearly a comet in images obtained with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala on 2023 Jan. 18.5 UT, as reported by R. Weryk (Department of Physics and Astronomy, University of Western Ontario). 2022 UT R.A. (2000) Decl. Mag. Oct. 3.49719 8 37 42.61 - 1 21 23.9 21.2 3.50140 8 37 42.77 - 1 21 25.5 20.6 3.50561 8 37 42.87 - 1 21 26.6 20.6 3.50982 8 37 43.01 - 1 21 28.4 21.1 Weryk notes that four 45-s w-band Pan-STARRS2 survey images show a very condensed head of size 1".9 (full-width-at-half-maximum) in 1".2 seeing with a broad tail 4" long spanning p.a. 300-360 deg. The available astrometry appears on MPEC 2023-C52. The following orbital elements by S. Nakano (Central Bureau) are from 97 observations spanning 2022 Oct. 3-2023 Feb. 1 (mean residual 0".5), with corresponding original and future values of 1/a being +0.000049 and -0.000281 (+/- 0.000037) AU**-1. There are no close approaches to major planets. Epoch = 2024 Feb. 20.0 TT T = 2024 Feb. 17.47856 TT Peri. = 324.31208 e = 0.9998038 Node = 236.91462 2000.0 q = 3.4449722 AU Incl. = 22.54348 The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 10.0 and 2.5n = 8 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2023 01 16 08 49.98 -10 10.7 4.106 4.946 145.3 6.5 18.6 2023 01 26 08 45.48 -10 20.4 4.005 4.886 150.5 5.7 18.5 2023 02 05 08 40.67 -10 17.4 3.931 4.827 152.4 5.4 18.4 2023 02 15 08 35.95 -10 02.2 3.885 4.768 150.3 5.9 18.4 2023 02 25 08 31.73 -09 36.3 3.865 4.710 144.9 6.9 18.3 2023 03 07 08 28.38 -09 02.1 3.870 4.652 137.7 8.3 18.3 2023 03 17 08 26.20 -08 22.5 3.897 4.595 129.5 9.6 18.3 2023 03 27 08 25.38 -07 40.3 3.942 4.538 121.1 10.8 18.2 2023 04 06 08 26.04 -06 58.6 4.002 4.483 112.6 11.9 18.2 2023 04 16 08 28.19 -06 19.6 4.072 4.428 104.3 12.7 18.2 2023 04 26 08 31.80 -05 45.4 4.149 4.374 96.2 13.2 18.2 2023 05 06 08 36.79 -05 17.5 4.230 4.321 88.4 13.5 18.2 2023 05 16 08 43.06 -04 57.0 4.311 4.268 80.8 13.5 18.2 2023 05 26 08 50.47 -04 44.5 4.390 4.217 73.6 13.3 18.2 2023 06 05 08 58.92 -04 40.5 4.464 4.167 66.6 12.9 18.2 2023 06 15 09 08.27 -04 45.1 4.533 4.118 59.9 12.3 18.2 2023 06 25 09 18.42 -04 58.3 4.593 4.070 53.4 11.6 18.2 2023 07 05 09 29.27 -05 20.0 4.644 4.024 47.2 10.7 18.2 2023 07 15 09 40.71 -05 49.8 4.685 3.978 41.3 9.7 18.2 2023 11 12 12 21.12 -19 08.6 4.274 3.561 39.1 10.1 17.6 2023 12 02 12 48.16 -21 47.6 4.052 3.519 51.2 12.6 17.4 2023 12 22 13 13.69 -24 13.8 3.799 3.486 64.2 14.7 17.2 2024 01 11 13 36.61 -26 18.4 3.526 3.462 78.2 16.1 17.1 2024 01 31 13 55.50 -27 51.9 3.247 3.449 93.4 16.6 16.9 2024 02 20 14 08.77 -28 43.3 2.980 3.445 109.9 15.7 16.7 2024 03 11 14 15.14 -28 40.8 2.750 3.451 127.9 13.1 16.5 2024 03 31 14 14.60 -27 33.8 2.585 3.467 147.2 9.0 16.4 2024 04 20 14 09.30 -25 23.9 2.512 3.493 165.5 4.1 16.3 2024 05 10 14 03.30 -22 34.7 2.547 3.528 164.0 4.5 16.4 2024 05 30 14 00.64 -19 45.8 2.691 3.573 145.5 9.2 16.6 2024 06 19 14 03.49 -17 31.4 2.925 3.626 126.8 13.0 16.8 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2023 CBAT 2023 February 9 (CBET 5218) Daniel W. E. Green