Electronic Telegram No. 5105 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 D2 (KOWALSKI) The Minor Planet Center reports (cf. MPEC 2022-E46) the discovery of a comet by R. A. Kowalski on CCD images taken on Feb. 25 (discovery observations tabulated below) with the Mt. Lemmon 1.5-m reflector; Kowalski reported an indication of activity around the nuclear condensation that became more apparent in four stacked 30-s exposures, describing the comet as having a very condensed 10" coma with no tail. Pre-discovery Mt. Lemmon images of the comet were subsequently identified also on Jan. 21.2 UT (at mag 20.4-21.1) and Feb. 14.2 (mag 19.6-20.1). 2022 UT R.A. (2000) Decl. Mag. Observer Feb. 25.12135 4 35 44.76 +34 23 24.4 19.8 Kowalski 25.12700 4 35 45.59 +34 23 17.5 " 25.13266 4 35 46.48 +34 23 11.3 20.2 " 25.13830 4 35 47.42 +34 23 05.3 19.8 " After the comet was posted on the Minor Planet Center's PCCP webpage, other CCD astrometrists have confirmed the cometary appearance. Sixteen stacked 60-s exposures taken remotely on Feb. 25.2 UT by H. Sato (Tokyo, Japan) with a 0.43-m f/6.8 astrograph located near Mayhill, NM, USA, show a moderately condensed, diffuse coma 15" in diameter with no tail; the magnitude was 19.4 as measured within a circular aperture of radius 9".6. Ten 60-s unfiltered exposures taken by F. Kugel (Dauban, France) with a 0.4-m f/2.8 reflector on Mar. 1.77-1.79 show a coma of size around 6" with a 20" tail in p.a. 290 degrees. L. Buzzi, Varese, Italy, writes that sixty stacked 60-s exposures taken on Mar. 1.8 by A. Aletti and himself in good conditions with a 0.84-m f/3.5 reflector show a moderately condensed coma 7" wide, clearly extended toward p.a. 80 degrees. The following nearly parabolic orbital elements by S. Nakano (Central Bureau) are from 74 observations spanning Jan. 21-Mar. 2 (mean residual 0".5). T = 2022 Mar. 27.57721 TT Peri. = 177.79304 e = 0.9958823 Node = 312.46957 2000.0 q = 1.5551510 AU Incl. = 22.65499 The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 17.0 and 2.5n = 8 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 01 21 03 21.63 +45 06.5 1.124 1.792 116.3 29.5 19.3 2022 01 26 03 29.10 +43 36.5 1.124 1.760 113.0 31.0 19.2 2022 01 31 03 37.78 +42 05.7 1.126 1.730 109.9 32.4 19.2 2022 02 05 03 47.57 +40 34.7 1.131 1.702 106.8 33.7 19.1 2022 02 10 03 58.34 +39 03.3 1.138 1.675 103.9 34.9 19.1 2022 02 15 04 09.99 +37 31.5 1.146 1.651 101.1 35.9 19.0 2022 02 20 04 22.39 +35 59.0 1.157 1.630 98.5 36.9 19.0 2022 02 25 04 35.42 +34 25.7 1.170 1.611 96.1 37.7 19.0 2022 03 02 04 49.00 +32 51.3 1.185 1.594 93.8 38.3 19.0 2022 03 07 05 03.03 +31 15.6 1.203 1.581 91.6 38.9 19.0 2022 03 12 05 17.39 +29 38.6 1.222 1.570 89.6 39.3 19.0 2022 03 17 05 32.00 +28 00.2 1.244 1.562 87.7 39.5 19.0 2022 03 22 05 46.76 +26 20.3 1.268 1.557 86.0 39.7 19.1 2022 03 27 06 01.60 +24 39.2 1.295 1.555 84.4 39.7 19.1 2022 04 01 06 16.47 +22 57.0 1.324 1.556 82.8 39.6 19.1 2022 04 06 06 31.29 +21 13.9 1.356 1.561 81.4 39.3 19.2 2022 04 11 06 46.02 +19 30.2 1.391 1.568 80.1 39.0 19.3 2022 04 16 07 00.61 +17 46.3 1.428 1.578 78.8 38.6 19.4 2022 04 21 07 15.03 +16 02.4 1.468 1.591 77.6 38.1 19.4 2022 04 26 07 29.25 +14 18.9 1.511 1.607 76.4 37.5 19.5 2022 05 01 07 43.26 +12 36.1 1.556 1.625 75.3 36.8 19.6 2022 05 06 07 57.04 +10 54.2 1.604 1.646 74.2 36.1 19.8 2022 05 11 08 10.59 +09 13.4 1.655 1.670 73.1 35.4 19.9 2022 05 16 08 23.88 +07 34.1 1.709 1.695 72.0 34.5 20.0 2022 05 21 08 36.93 +05 56.3 1.765 1.723 70.9 33.7 20.1 2022 05 26 08 49.73 +04 20.2 1.824 1.753 69.7 32.8 20.3 2022 05 31 09 02.28 +02 46.0 1.885 1.785 68.6 31.9 20.4 2022 06 05 09 14.61 +01 13.6 1.948 1.818 67.4 31.0 20.5 2022 06 10 09 26.69 -00 16.9 2.014 1.853 66.2 30.1 20.7 2022 06 15 09 38.55 -01 45.4 2.082 1.890 64.9 29.1 20.8 2022 06 20 09 50.19 -03 11.9 2.152 1.927 63.6 28.2 20.9 2022 06 25 10 01.62 -04 36.5 2.223 1.966 62.2 27.2 21.1 2022 06 30 10 12.84 -05 59.1 2.296 2.007 60.8 26.2 21.2 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 March 3 (CBET 5105) Daniel W. E. Green