Electronic Telegram No. 5111 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 E3 (ZTF) An apparently asteroidal object discovered in a survey called the "Zwicky Transient Facility" (ZTF), in CCD images taken using the 1.2-m f/2.4 Schmidt telescope at Palomar (discovery observations tabulated below), has been found to show cometary activity by CCD astrometrists elsewhere. 2022 UT R.A. (2000) Decl. Mag. Mar. 2.54453 19 59 03.50 + 1 49 18.4 17.2 2.54700 19 59 03.57 + 1 49 19.7 17.3 2.54948 19 59 03.65 + 1 49 20.9 17.3 2.55195 19 59 03.73 + 1 49 22.0 17.3 2.55443 19 59 03.81 + 1 49 23.3 17.2 Ten stacked 60-s CCD exposures taken remotely on Mar. 3.52 UT by H. Sato (Tokyo, Japan) with a 0.43-m f/6.8 astrograph located near Mayhill, NM, USA, show a strongly condensed, fuzzy coma 8" in diameter with no tail; the magnitude was 17.7 as measured within a circular aperture of radius 5".7. Fifteen stacked 60-s CCD exposures taken remotely by K. Yoshimoto (Kumage, Yamaguchi, Japan) on Mar. 19.5 with a 0.50-m f/6.8 reflector near Mayhill show a very condensed coma 15" in diameter and a faint tail 25" long in p.a. 310 deg; the total magnitude was given as 16.7. E. Guido, Castellammare di Stabia, Italy, writes that twelve stacked 120-s unfiltered CCD exposures obtained remotely by a large group of observers on Mar. 20.4 with a "Telescope Live" 0.61-m f/6.5 astrograph located at El Sauce, Chile, show a compact coma about 9" in diameter with total mag 16.3-17.0. The available astrometry appears on MPEC 2022-F13. The following parabolic orbital elements by S. Nakano (Central Bureau) are from 62 observations spanning Mar. 2-21 (mean residual 0".3). These preliminary elements indicate that the comet will pass 0.28 AU from the earth in early Feb. 2023, when the comet may be near total visual magnitude 6; these also suggest that the comet passed about 1.18 AU from Saturn in 2020 May and about 3.07 AU from Jupiter in 2021 April. T = 2023 Jan. 12.83044 TT Peri. = 145.82395 Node = 302.55725 2000.0 q = 1.1123373 AU Incl. = 109.17556 The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 8.0 and 2.5n = 8 for the magnitudes; the ephemeris is given nearly a year into the future for planning purposes only. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 03 02 19 58.77 +01 44.9 4.937 4.276 43.7 9.2 16.5 2022 03 12 20 03.68 +03 11.0 4.723 4.174 51.3 10.7 16.3 2022 03 22 20 07.92 +04 47.7 4.494 4.072 59.1 12.1 16.1 2022 04 01 20 11.30 +06 35.9 4.253 3.969 66.9 13.4 15.9 2022 04 11 20 13.56 +08 36.5 4.003 3.865 74.9 14.5 15.7 2022 04 21 20 14.43 +10 50.4 3.750 3.760 82.9 15.4 15.5 2022 05 01 20 13.56 +13 18.7 3.498 3.654 90.8 16.0 15.2 2022 05 11 20 10.52 +16 01.5 3.251 3.548 98.7 16.3 15.0 2022 05 21 20 04.81 +18 58.4 3.016 3.440 106.3 16.4 14.7 2022 05 31 19 55.82 +22 07.0 2.797 3.332 113.4 16.2 14.4 2022 06 10 19 42.93 +25 21.8 2.602 3.223 119.3 15.9 14.1 2022 06 20 19 25.64 +28 33.4 2.435 3.112 123.4 15.8 13.9 2022 06 30 19 03.74 +31 27.9 2.302 3.001 124.9 16.1 13.6 2022 07 10 18 37.77 +33 48.1 2.205 2.890 123.2 17.1 13.4 2022 07 20 18 09.18 +35 19.2 2.145 2.777 118.5 18.8 13.2 2022 07 30 17 40.17 +35 53.7 2.119 2.664 111.5 20.8 13.0 2022 08 09 17 13.12 +35 34.9 2.120 2.550 103.1 22.8 12.9 2022 08 19 16 49.72 +34 35.1 2.142 2.435 94.2 24.5 12.7 2022 08 29 16 30.74 +33 09.3 2.174 2.320 85.2 25.7 12.6 2022 09 08 16 16.17 +31 31.8 2.209 2.204 76.6 26.4 12.5 2022 09 18 16 05.53 +29 53.4 2.238 2.089 68.4 26.6 12.3 2022 09 28 15 58.17 +28 21.4 2.255 1.974 61.0 26.4 12.1 2022 10 08 15 53.47 +27 00.6 2.254 1.861 54.5 25.9 11.9 2022 10 18 15 50.82 +25 54.1 2.229 1.749 49.2 25.6 11.7 2022 10 28 15 49.73 +25 04.1 2.177 1.639 45.4 25.6 11.4 2022 11 07 15 49.75 +24 32.9 2.094 1.534 43.4 26.4 11.1 2022 11 17 15 50.49 +24 22.7 1.978 1.434 43.6 28.4 10.7 2022 11 27 15 51.62 +24 37.0 1.827 1.342 45.8 31.8 10.3 2022 12 07 15 52.79 +25 21.4 1.642 1.261 50.1 36.8 9.9 2022 12 17 15 53.64 +26 46.1 1.423 1.194 56.0 43.1 9.4 2022 12 27 15 53.70 +29 13.2 1.174 1.146 63.4 50.2 8.8 2023 01 06 15 51.90 +33 36.3 0.901 1.118 72.6 57.1 8.2 2023 01 16 15 44.44 +42 33.7 0.617 1.114 84.9 61.6 7.3 2023 01 26 14 54.18 +65 51.5 0.362 1.133 104.9 57.1 6.2 2023 02 05 05 17.11 +52 11.0 0.304 1.174 121.7 45.6 6.0 2023 02 15 04 42.09 +16 32.5 0.523 1.235 105.5 50.4 7.3 2023 02 25 04 38.07 +04 07.6 0.816 1.311 92.6 49.0 8.5 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 March 21 (CBET 5111) Daniel W. E. Green