Electronic Telegram No. 5426 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 P/2024 N6 = P/2002 QU_151 (NEAT-PANSTARRS) R. Weryk, Department of Physics and Astronomy, University of Western Ontario, reports the discovery of another comet in images obtained with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala (discovery observations tabulated below). 2024 UT R.A. (2000) Decl. Mag. July 9.58965 1 35 51.69 +16 27 27.2 20.6 9.59435 1 35 52.18 +16 27 32.4 20.5 9.60374 1 35 53.18 +16 27 43.0 20.4 Weryk arranged for three 40-s gri-band images to be taken (with R. Wainscoat) at the 3.6-m Canada-France-Hawaii Telescope atop Mauna Kea on 2024 Sept. 11.6 UT (queue observer L. Wells; queue coordinator V. Khatu), which show this object to be clearly cometary in 1".0 seeing, with a condensed head of size 1".5 (full-width-at-half-maximum) and a straight tail 8" long toward p.a. 230 degrees (at which point Weryk moved the comet from the Minor Planet Center's NEOCP webpage to its PCCP webpage). Three additional 30-s gri-band CFHT images obtained on July 13.58 (queue observer J. Silva; queue coordinator H. Flewelling) in 2".0 seeing show a condensed head of size 2".3 and a straight 8" tail in p.a. 230 deg. Weryk also identified this comet with an apparently asteroidal object discovered by the NEAT survey in 2002 (and given the minor-planet designation 2002 QU_151 on MPS 428166; discovery observations tabulated below); there was a 2-month arc of observations in 2002. 2002 UT R.A. (2000) Decl. Mag. July 6.46470 20 51 31.90 -30 41 23.0 20.4 6.47516 20 51 31.72 -30 41 18.1 20.6 6.48564 20 51 31.52 -30 41 14.7 19.7 16.36907 20 48 20.94 -29 28 46.0 20.1 16.39347 20 48 20.09 -29 28 34.5 19.2 16.41959 20 48 19.24 -29 28 20.9 19.4 Aug. 18.18108 20 29 17.28 -22 50 14.2 19.0 18.20190 20 29 16.68 -22 49 55.9 18.8 18.22270 20 29 16.14 -22 49 37.3 19.3 29.21512 20 27 05.61 -20 01 27.5 19.0 29.23632 20 27 05.53 -20 01 07.7 19.0 29.25767 20 27 05.45 -20 00 48.1 19.6 H. Sato (Bunkyo-ku, Tokyo, Japan) writes that ten stacked 60-s CCD exposures taken remotely on 2024 July 18.4 UT with a "Deep Sky Chile" 0.51-m f/6.8 astrograph located at Rio Hurtado, Chile, show only a stellar appearance; the PCCP P21WnsB appeared stellard on 10-stacked images of 60-sec exposure. magnitude was 21.0 as measured within a circular aperture of radius 2".2. S. Deen (Simi Valley, CA, USA) relates that he found archival images of this comet in DECam images taken with the 4-m Cerro Tololo reflector on two nights in April of this year. on 2024 Apr. 18.4, there appears to be a coma of size 1".5 (FWHM) in 0".6 seeing and possibly a faint 2".5 tail in p.a. 250 degrees (magnitude r = 21.8-22.3). On Apr. 19.4, there is a coma of size 1".2 (FWHM) in 0".7 seeing but no clear tail. The available astrometry appears on MPEC 2024-P41. The following linked orbital elements by S. Nakano (Central Bureau) are from 66 observations spanning 2002 July 6-2024 Aug. 2 (mean residual 0".4). The comet passed 0.38 AU from Jupiter on 1991 June 3 UT, and it will pass 0.71 AU from Jupiter on 2026 June 27 and 0.55 AU from Jupiter on 2051 Jan. 7 UT. Epoch = 1995 June 12.0 TT T = 1995 June 3.35428 TT Peri. = 1.16670 e = 0.5484207 Node = 324.22168 2000.0 q = 1.6892906 AU Incl. = 11.36163 a = 3.7408505 AU n = 0.13622240 P = 7.24 years Epoch = 2002 Sept. 3.0 TT T = 2002 Sept. 3.92009 TT Peri. = 1.25292 e = 0.5471001 Node = 324.16139 2000.0 q = 1.6985286 AU Incl. = 11.34129 a = 3.7503402 AU n = 0.13570570 P = 7.26 years Epoch = 2009 Nov. 25.0 TT T = 2009 Dec. 3.57038 TT Peri. = 1.26578 e = 0.5487151 Node = 324.15829 2000.0 q = 1.6900048 AU Incl. = 11.36186 a = 3.7448732 AU n = 0.13600297 P = 7.25 years Epoch = 2017 Feb. 16.0 TT T = 2017 Feb. 25.12006 TT Peri. = 1.29960 e = 0.5495924 Node = 324.15045 2000.0 q = 1.6834277 AU Incl. = 11.35621 a = 3.7375655 AU n = 0.13640204 P = 7.23 years Epoch = 2024 May 10.0 TT T = 2024 May 19.15645 TT Peri. = 1.44687 e = 0.5504216 Node = 324.07491 2000.0 q = 1.6777942 AU Incl. = 11.36468 a = 3.7319278 AU n = 0.13671124 P = 7.21 years Epoch = 2031 Nov. 30.0 TT T = 2031 Dec. 2.27973 TT Peri. = 5.86698 e = 0.5224243 Node = 321.81561 2000.0 q = 1.8513430 AU Incl. = 11.83611 a = 3.8765431 AU n = 0.12913297 P = 7.63 years Epoch = 2039 July 31.0 TT T = 2039 July 28.60105 TT Peri. = 5.97995 e = 0.5216783 Node = 321.77774 2000.0 q = 1.8600198 AU Incl. = 11.81924 a = 3.8886377 AU n = 0.12853099 P = 7.67 years Epoch = 2047 Mar. 31.0 TT T = 2047 Mar. 23.62556 TT Peri. = 6.04588 e = 0.5231779 Node = 321.73672 2000.0 q = 1.8482451 AU Incl. = 11.83833 a = 3.8761737 AU n = 0.12915143 P = 7.63 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 16.0 and 2.5n = 10 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2024 07 29 02 07.57 +21 59.7 1.524 1.814 88.8 34.0 19.5 2024 08 03 02 14.59 +23 18.2 1.498 1.832 91.6 33.6 19.5 2024 08 08 02 21.04 +24 33.6 1.472 1.852 94.5 33.1 19.5 2024 08 13 02 26.85 +25 45.9 1.447 1.872 97.5 32.4 19.5 2024 08 18 02 31.98 +26 54.9 1.422 1.893 100.8 31.7 19.5 2024 08 23 02 36.35 +28 00.5 1.397 1.915 104.2 30.8 19.5 2024 08 28 02 39.92 +29 02.4 1.374 1.938 107.8 29.8 19.6 2024 09 02 02 42.59 +30 00.5 1.351 1.961 111.6 28.6 19.6 2024 09 07 02 44.33 +30 54.2 1.330 1.985 115.5 27.3 19.6 2024 09 12 02 45.09 +31 43.2 1.311 2.010 119.7 25.8 19.6 2024 09 17 02 44.85 +32 26.9 1.294 2.035 124.0 24.2 19.6 2024 09 22 02 43.61 +33 04.8 1.280 2.060 128.5 22.4 19.7 2024 09 27 02 41.40 +33 36.0 1.269 2.086 133.1 20.5 19.7 2024 10 02 02 38.26 +34 00.0 1.261 2.113 137.8 18.5 19.8 2024 10 07 02 34.31 +34 16.1 1.258 2.140 142.6 16.5 19.8 2024 10 12 02 29.71 +34 23.9 1.259 2.167 147.3 14.4 19.9 2024 10 17 02 24.63 +34 23.4 1.265 2.194 151.7 12.4 19.9 2024 10 22 02 19.28 +34 14.6 1.277 2.222 155.6 10.7 20.0 2024 10 27 02 13.88 +33 58.2 1.295 2.250 158.7 9.2 20.1 2024 11 01 02 08.63 +33 35.0 1.319 2.278 160.5 8.4 20.2 2024 11 06 02 03.74 +33 06.1 1.348 2.307 160.5 8.3 20.3 2024 11 11 01 59.37 +32 33.1 1.385 2.335 158.8 8.8 20.4 2024 11 16 01 55.67 +31 57.4 1.427 2.364 155.8 9.9 20.5 2024 11 21 01 52.69 +31 20.6 1.475 2.393 152.0 11.2 20.6 2024 11 26 01 50.49 +30 43.7 1.529 2.422 147.8 12.5 20.8 2024 12 06 01 48.49 +29 34.4 1.653 2.480 138.7 15.2 21.0 2024 12 16 01 49.57 +28 36.2 1.796 2.539 129.6 17.4 21.3 2024 12 26 01 53.37 +27 51.9 1.954 2.598 120.7 19.0 21.6 2025 01 05 01 59.49 +27 22.1 2.125 2.656 112.1 20.1 21.9 2025 01 15 02 07.55 +27 05.9 2.305 2.715 103.9 20.6 22.2 2025 01 25 02 17.18 +27 01.4 2.492 2.773 96.0 20.7 22.4 2025 02 04 02 28.09 +27 06.6 2.682 2.832 88.4 20.4 22.7 2025 02 14 02 40.06 +27 19.4 2.873 2.890 81.1 19.7 22.9 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2024 CBAT 2024 August 4 (CBET 5426) Daniel W. E. Green