Electronic Telegram No. 5350 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/2024 C2 (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, Hawaii, on Feb. 1 (discovery observations tabulated below). Four 45-s w-band survey images taken in 1".4-1".6 seeing show a condensed head of size 2".0 (full-width-at- half-maximum) and no tail. 2024 UT R.A. (2000) Decl. Mag. Feb. 1.41828 9 51 51.85 +43 21 57.8 20.5 1.42938 9 51 51.59 +43 21 59.6 20.5 1.44049 9 51 51.37 +43 22 00.9 20.4 1.45161 9 51 51.09 +43 22 02.7 20.6 1.57820 9 51 48.36 +43 22 20.4 20.1 Weryk then identified presumably asteroidal pre-discovery Pan-STARRS2 images of the comet taken on 2023 Dec. 25.54-25.57 UT (at mag 21.9-22.6), 2024 Jan. 5.67 (mag 21.3), Jan. 20.7 and 21.7 (mag 20.5), and Jan. 23.42-23.45 (mag 20.5-20.9). He also identified the comet in pre-discovery observations obtained with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala on 2024 Jan. 6.58-6.65 (mag 20.8-21.2) and Jan. 22.5 (mag 20.1-20.4). M. Jaeger, Vienna, writes that CCD images obtained by E. Prosperi, S. Prosperi, and himself on Feb. 1.85-1.87 UT with a 0.3-m f/4 reflector located at Oed, Martinsberg, Austria, show a strongly condensed coma of size 5" and mag 20.0 with a tail 12" long in p.a. 288 degrees. The object appeared stellar on CCD images obtained on Feb. 1.92-1.95 by A. Aletti with a 0.36-m f/7.5 reflector at Varese, Italy (mag 20.2-20.4). On Feb. 11.95-11.98, Aletti obtained one-hundred-thirty-three stacked 30-s exposures with the same telescope (measured by M. Auteri and himself) in 3".7 seeing that show a condensed coma of size 5" that is extended toward the southwest; the magnitude was measured to be 19.4-19.6. Eight stacked 120-s CCD exposures taken remotely by H. Sato (Bunkyo-ku, Tokyo, Japan) on Feb. 11.3 with a 0.61-m f/6.5 astrograph located at the Sierra Remote Observatory near Auberry, CA, USA, show a strongly condensed coma 7" in diameter with no tail; the magnitude was 19.5 as measured within a circular aperture of radius 3".8. The available astrometry appears on MPEC 2024-C178. The following two- body orbital elements by S. Nakano (Central Bureau) are from 54 observations spanning 2023 Dec. 25-2024 Feb. 11 (mean residual 0".2). The orbital period has a formal error of +/- 26.9 days. There is no close approach to any major planets. T = 2025 Mar. 16.42419 TT Peri. = 87.81634 e = 0.4445150 Node = 66.43373 2000.0 q = 8.9869544 AU Incl. = 27.28283 a = 16.1785725 AU n = 0.01514585 P = 65.1 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 7.5 and 2.5n = 8 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2024 01 11 09 58.36 +42 20.8 8.337 9.136 142.3 3.8 19.8 2024 01 21 09 55.64 +42 51.7 8.278 9.129 148.1 3.3 19.8 2024 01 31 09 52.36 +43 18.6 8.246 9.122 151.2 3.0 19.8 2024 02 10 09 48.73 +43 40.0 8.242 9.116 150.8 3.0 19.8 2024 02 20 09 44.98 +43 54.8 8.265 9.110 146.9 3.4 19.8 2024 03 01 09 41.36 +44 02.4 8.315 9.104 140.8 3.9 19.8 2024 03 11 09 38.11 +44 02.6 8.388 9.098 133.3 4.6 19.8 2024 03 21 09 35.44 +43 55.6 8.482 9.092 125.1 5.1 19.8 2024 03 31 09 33.50 +43 41.9 8.593 9.086 116.7 5.6 19.8 2024 04 10 09 32.40 +43 22.3 8.718 9.080 108.2 6.0 19.9 2024 04 20 09 32.20 +42 57.7 8.852 9.075 99.7 6.3 19.9 2024 04 30 09 32.89 +42 29.2 8.991 9.070 91.3 6.4 19.9 2024 05 10 09 34.47 +41 57.4 9.132 9.065 83.0 6.3 20.0 2024 05 20 09 36.88 +41 23.2 9.269 9.060 75.0 6.2 20.0 2024 05 30 09 40.05 +40 47.4 9.401 9.055 67.1 5.9 20.0 2024 06 09 09 43.90 +40 10.5 9.523 9.051 59.5 5.5 20.0 2024 06 19 09 48.34 +39 33.2 9.634 9.046 52.2 5.1 20.1 2024 09 27 10 47.88 +34 29.8 9.737 9.011 41.5 4.2 20.1 2024 10 07 10 53.71 +34 15.9 9.640 9.008 48.4 4.8 20.1 2024 10 17 10 59.21 +34 06.8 9.527 9.005 55.9 5.3 20.0 2024 10 27 11 04.33 +34 02.7 9.400 9.003 63.6 5.7 20.0 2024 11 06 11 08.96 +34 04.1 9.263 9.001 71.7 6.0 20.0 2024 11 16 11 13.04 +34 11.1 9.118 8.999 80.0 6.2 19.9 2024 11 26 11 16.48 +34 23.8 8.969 8.997 88.5 6.3 19.9 2024 12 06 11 19.21 +34 41.9 8.821 8.995 97.1 6.2 19.9 2024 12 16 11 21.14 +35 05.0 8.676 8.994 105.8 6.0 19.8 2024 12 26 11 22.25 +35 32.3 8.541 8.992 114.4 5.7 19.8 2025 01 05 11 22.49 +36 02.9 8.418 8.991 123.0 5.3 19.8 2025 01 15 11 21.87 +36 35.3 8.313 8.990 131.1 4.7 19.7 2025 01 25 11 20.42 +37 07.9 8.228 8.989 138.5 4.2 19.7 2025 02 04 11 18.23 +37 39.0 8.166 8.988 144.7 3.6 19.7 2025 02 14 11 15.43 +38 06.7 8.130 8.988 148.6 3.3 19.7 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2024 CBAT 2024 February 15 (CBET 5350) Daniel W. E. Green