Electronic Telegram No. 5167 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 Q2 (ATLAS) An apparently asteroidal object discovered on CCD images taken on Aug. 27 UT with a 0.5-m f/2 Schmidt reflector at Mauna Loa, Hawaii, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program has been found to show cometary appearance by CCD astrometrists elsewhere after it was posted on the Minor Planet Center's PCCP webpage. The discovery observations are tabulated below, 2022 UT R.A. (2000) Decl. Mag. Aug. 27.58700 3 01 16.89 - 1 23 13.3 19.0 27.58882 3 01 16.73 - 1 23 16.2 19.2 27.59429 3 01 16.28 - 1 23 17.8 19.0 27.61658 3 01 14.34 - 1 23 29.9 19.1 Fifty-nine stacked 60-s exposures taken remotely by A. Aletti, F. Bellini, L. Buzzi, and G. Galli with a 0.36-m f/8.4 reflector at Hakos, Namibia, on Aug. 29.0 UT show a condensed 5" coma of mag 19.2 with a straight, faint tail possibly up to 10" long in p.a. 265 degrees. Ten stacked 60-s exposures taken remotely by H. Sato (Bunkyo-ku, Tokyo, Japan) on Aug. 30.5 with a 0.61-m f/6.5 astrograph located at the Sierra Remote Observatory near Auberry, CA, USA, show a strongly condensed coma 8" in diameter with no tail; the magnitude was 19.1 as measured within a circular aperture of radius 5".0. Fifteen unfiltered 60-s exposures taken on Sept. 2.14 (and six additional 60-s exposures taken on Sept. 5.1) by F. Kugel at Dauban, France, with a 0.4-m f/2.8 reflector show a coma of size around 10" of magnitude 18.6-18.9 in an aperture of radius 5".8; on Sept. 2, Kugel also noted a fan tail 30" long toward p.a. 310 deg. The available astrometry appears on MPEC 2022-R123. The following parabolic orbital elements by S. Nakano (Central Bureau) are from 104 spanning observations 2022 Aug. 27-Sept. 6 (mean residual 0".4); he notes that this may be a 1P/Halley-like comet with a fairly long orbital period (perhaps around 150 yr). T = 2023 Jan. 28.04212 TT Peri. = 42.23726 Node = 352.71964 2000.0 q = 1.6607652 AU Incl. = 151.71355 The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 13.0 and 2.5n = 10 for the magnitudes. While the orbit is preliminary, an ephemeris is extended into December to give an indication of its general position on the sky and its expected brightness. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 08 09 03 18.72 +00 38.7 2.563 2.735 88.8 21.8 19.4 2022 08 14 03 15.62 +00 14.3 2.418 2.689 94.2 22.1 19.2 2022 08 19 03 11.48 -00 15.8 2.274 2.644 99.9 22.2 19.0 2022 08 24 03 06.07 -00 52.4 2.132 2.598 105.9 22.0 18.8 2022 08 29 02 59.16 -01 36.5 1.992 2.553 112.3 21.5 18.6 2022 09 03 02 50.44 -02 28.9 1.857 2.508 119.2 20.6 18.3 2022 09 08 02 39.60 -03 30.5 1.728 2.464 126.5 19.2 18.1 2022 09 13 02 26.26 -04 42.0 1.607 2.420 134.3 17.3 17.9 2022 09 18 02 10.08 -06 03.4 1.498 2.376 142.6 14.9 17.6 2022 09 23 01 50.75 -07 33.6 1.403 2.333 151.1 12.0 17.4 2022 09 28 01 28.20 -09 09.6 1.326 2.291 159.1 9.0 17.2 2022 10 03 01 02.66 -10 46.0 1.270 2.249 163.9 7.1 17.0 2022 10 08 00 34.83 -12 15.8 1.237 2.208 161.5 8.3 16.9 2022 10 13 00 05.87 -13 31.8 1.229 2.167 153.4 11.9 16.8 2022 10 18 23 37.16 -14 28.5 1.244 2.128 143.2 16.3 16.8 2022 10 23 23 10.04 -15 04.1 1.282 2.089 132.7 20.5 16.7 2022 10 28 22 45.48 -15 20.0 1.339 2.052 122.5 24.1 16.8 2022 11 07 22 05.65 -15 08.0 1.493 1.980 103.8 29.1 16.8 2022 11 17 21 37.45 -14 22.5 1.679 1.913 87.6 31.1 16.9 2022 11 27 21 18.29 -13 23.0 1.874 1.852 73.4 30.7 17.0 2022 12 07 21 05.50 -12 18.2 2.062 1.798 60.7 28.5 17.1 2022 12 17 20 57.03 -11 11.3 2.232 1.752 49.1 25.1 17.2 2022 12 27 20 51.48 -10 02.7 2.376 1.715 38.2 20.8 17.2 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 September 7 (CBET 5167) Daniel W. E. Green