Electronic Telegram No. 5158 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 P1 (NEOWISE) Jana P. Chesley, Jet Propulsion Laboratory, reports the discovery of a comet in infrared images obtained during Aug. 8-9 UT with the Near-Earth Object Wide-field Infrared Survey Explorer (or NEOWISE; formerly the WISE earth-orbiting satellite; cf. CBET 4225). The object shows clear signs of cometary activity in the NEOWISE 4.6-micron band, displaying extended features that are slightly elongated, with a size around 1' in diameter; the comet was also detected in the NEOWISE 3.4-micron band, but signs of activity are weaker and more circular in that band. The discovery observations are tabulated below, in which the listed optical-wavelength magnitude was roughly estimated based on past WISE and NEOWISE cometary observations. 2022 UT R.A. (2000) Decl. Mag. Aug. 8.35041 2 59 28.42 +12 54 33.6 18 8.48081 2 59 23.81 +12 52 30.0 8.48093 2 59 23.65 +12 52 21.7 8.54613 2 59 21.29 +12 51 14.7 8.61133 2 59 18.97 +12 50 07.8 8.74172 2 59 14.18 +12 47 53.2 8.74185 2 59 14.13 +12 47 52.9 8.93744 2 59 06.85 +12 44 30.3 9.06796 2 59 01.89 +12 42 13.8 After the comet was posted on the Minor Planet Center's PCCP webpage, other CCD astrometrists have also reported the cometary appearance to the Central Bureau. Twelve stacked 60-s exposures taken remotely by H. Sato (Tokyo, Japan) on Aug. 13.48 UT with an iTelescope 0.61-m f/6.5 astrograph at Auberry, CA, USA, show a strongly condensed coma 12" in diameter with no tail; the magnitude was 17.3 as measured within a circular aperture of radius 6".5. One hundred 30-s exposures taken by L. Buzzi, Varese, Italy, with a 0.84-m f/3.5 reflector on Aug. 14.05-14.08 (measured by Buzzi and A. Aletti) show a condensed coma 11" wide with a broad tail 15" long toward p.a. 40 degrees; the magnitude was given as 17.8. K. Yoshimoto, Yamaguchi, Japan, writes that ten stacked 60-s exposures taken remotely with a 0.50-m f/6.8 reflector located at Mayhill, NM, USA, on Aug. 14.48 show a condensed coma 27" in diameter and no tail; the total magnitude was measured to be 16.5. The available astrometry appears on MPEC 2022-Q03. The following parabolic orbital elements by S. Nakano (Central Bureau) are from 57 observations spanning Aug. 8-15 (mean residual 0".4). These suggest that the comet is now passing 3.01 AU from Jupiter. T = 2022 Nov. 24.62641 TT Peri. = 248.39979 Node = 205.41430 2000.0 q = 1.6100047 AU Incl. = 154.71964 The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 13.0 and 2.5n = 8 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 06 30 02 59.87 +18 47.6 3.027 2.498 50.0 18.2 18.6 2022 07 05 03 01.46 +18 24.3 2.898 2.452 54.5 19.7 18.4 2022 07 10 03 02.73 +17 57.0 2.765 2.407 59.1 21.3 18.3 2022 07 15 03 03.63 +17 24.8 2.627 2.362 63.8 22.7 18.1 2022 07 20 03 04.08 +16 46.8 2.485 2.318 68.7 24.1 17.9 2022 07 25 03 03.99 +16 01.5 2.340 2.274 73.7 25.4 17.7 2022 07 30 03 03.23 +15 07.4 2.191 2.230 78.9 26.5 17.5 2022 08 04 03 01.65 +14 02.3 2.041 2.188 84.3 27.5 17.3 2022 08 09 02 59.08 +12 43.4 1.890 2.146 90.1 28.2 17.0 2022 08 14 02 55.26 +11 07.1 1.739 2.105 96.2 28.6 16.8 2022 08 19 02 49.90 +09 08.4 1.589 2.065 102.8 28.6 16.5 2022 08 24 02 42.55 +06 40.9 1.443 2.025 110.0 28.0 16.2 2022 08 29 02 32.67 +03 36.5 1.304 1.987 117.8 26.7 16.0 2022 09 03 02 19.53 -00 14.5 1.174 1.950 126.5 24.6 15.7 2022 09 08 02 02.24 -05 01.9 1.058 1.914 135.9 21.5 15.4 2022 09 13 01 39.71 -10 50.7 0.963 1.880 145.4 17.7 15.1 2022 09 18 01 10.91 -17 33.0 0.895 1.847 153.0 14.3 14.9 2022 09 23 00 35.33 -24 37.2 0.860 1.816 154.0 14.0 14.7 2022 09 28 23 53.84 -31 09.8 0.862 1.786 146.6 18.0 14.7 2022 10 03 23 09.32 -36 19.4 0.901 1.759 135.2 23.6 14.7 2022 10 08 22 25.95 -39 44.6 0.969 1.733 123.4 28.8 14.8 2022 10 13 21 47.32 -41 37.3 1.061 1.710 112.3 32.7 15.0 2022 10 18 21 15.18 -42 24.7 1.167 1.688 102.3 35.2 15.2 2022 10 23 20 49.53 -42 32.6 1.284 1.669 93.3 36.5 15.3 2022 10 28 20 29.52 -42 19.0 1.406 1.653 85.3 36.8 15.5 2022 11 02 20 14.04 -41 55.3 1.529 1.639 77.9 36.3 15.6 2022 11 07 20 02.10 -41 27.6 1.652 1.628 71.1 35.2 15.8 2022 11 12 19 52.87 -40 59.5 1.772 1.619 64.7 33.6 15.9 2022 11 17 19 45.75 -40 32.5 1.888 1.613 58.7 31.6 16.0 2022 11 22 19 40.26 -40 07.6 1.999 1.610 53.0 29.3 16.2 2022 11 27 19 36.06 -39 45.0 2.103 1.610 47.5 26.9 16.3 2022 12 02 19 32.86 -39 25.0 2.200 1.613 42.3 24.3 16.4 2022 12 07 19 30.44 -39 07.5 2.288 1.619 37.3 21.6 16.5 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 August 16 (CBET 5158) Daniel W. E. Green