Electronic Telegram No. 5516 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/2025 B3 = P/2019 A8 (PANSTARRS) Recovery observations of comet P/2019 A8 (cf. CBET 4608) have been found by T. Kobayashi (Oizumi, Gunma-ken, Japan) in incidental survey astrometry from the Minor Planet Center's "isolated tracklet file" (which is accessible publicly), as observed with the Mt. Lemmon 1.5-m reflector on Jan. 24 and on Feb. 2 and 5 (tabulated below), and with the Pan-STARRS2 1.8-m reflector at Haleakala on Feb. 5.33-5.37 UT (at mag 20.7-20.9). 2025 UT R.A. (2000) Decl. Mag. Jan. 24.39015 9 37 54.07 +15 47 28.6 21.3 24.39541 9 37 53.85 +15 47 29.7 21.1 24.40072 9 37 53.69 +15 47 31.4 21.2 24.40600 9 37 53.53 +15 47 32.8 20.9 Feb. 2.31040 9 32 29.00 +16 29 43.5 20.9 2.31606 9 32 28.71 +16 29 45.9 20.7 2.32169 9 32 28.43 +16 29 47.0 20.8 2.32735 9 32 28.29 +16 29 49.2 20.9 5.25577 9 30 28.31 +16 44 19.6 5.26140 9 30 28.10 +16 44 21.3 5.26703 9 30 27.82 +16 44 22.8 20.4 The comet was independently recovered on CMOS images obtained on Feb. 22.0 UT at Martinsberg, Oed, Austria, by M. Jaeger, G. Rhemann, and E. Prosperi, with a 0.35-m f/4.2 reflector. Jaeger writes that thirty-nine 70-s exposures show a coma of size 6" and total mag 20.1 with a faint 12"-long tail in p.a. 248 degrees. Additional astrometry appears on MPEC 2025-D234. Because comet was observed in a short arc (55 days) at the previous return, and the orbit was changed due to a close approach to Jupiter (0.26 AU) on 2021 Nov. 1, the indicated correction is Delta(T) = +49.2 days from the prediction in NK 5033 (and ICQ's 2025 Comet Handbook). The following linked orbital elements by S. Nakano (Central Bureau) are from 66 observations spanning 2018 Dec. 16-2025 June 25 (mean residual 0".5). The comet also passed 0.27 AU from Jupiter on 2009 Nov. 26 UT. Epoch = 1998 Dec. 13.0 TT T = 1998 Nov. 24.06275 TT Peri. = 1.29385 e = 0.3361540 Node = 134.34789 2000.0 q = 2.4034446 AU Incl. = 2.70923 a = 3.6204850 AU n = 0.14307177 P = 6.89 years Epoch = 2005 Sept.27.0 TT T = 2005 Oct. 15.73451 TT Peri. = 1.48583 e = 0.3373614 Node = 134.32072 2000.0 q = 2.3960615 AU Incl. = 2.71116 a = 3.6159402 AU n = 0.14334159 P = 6.88 years Epoch = 2012 Sept.30.0 TT T = 2012 Sept.26.65395 TT Peri. = 20.22761 e = 0.4276347 Node = 127.92292 2000.0 q = 1.8719869 AU Incl. = 2.96657 a = 3.2706156 AU n = 0.16663254 P = 5.92 years Epoch = 2018 Aug. 30.0 TT T = 2018 Aug. 30.74303 TT Peri. = 20.40194 e = 0.4274762 Node = 127.89504 2000.0 q = 1.8729519 AU Incl. = 2.96678 a = 3.2713956 AU n = 0.16657295 P = 5.92 years Epoch = 2025 Mar. 26.0 TT T = 2025 Mar. 31.93143 TT Peri. = 46.68240 e = 0.3758977 Node = 111.53024 2000.0 q = 2.1317498 AU Incl. = 2.30150 a = 3.4157055 AU n = 0.15612895 P = 6.31 years Epoch = 2031 Aug. 2.0 TT T = 2031 July 29.36661 TT Peri. = 46.87868 e = 0.3749327 Node = 111.50477 2000.0 q = 2.1363939 AU Incl. = 2.30121 a = 3.4178624 AU n = 0.15598118 P = 6.32 years Epoch = 2037 Dec. 8.0 TT T = 2037 Dec. 9.92546 TT Peri. = 47.00337 e = 0.3653288 Node = 111.25958 2000.0 q = 2.1910633 AU Incl. = 2.29589 a = 3.4522812 AU n = 0.15365434 P = 6.41 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 16.5 and 2.5n = 10 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2025 02 14 09 24.31 +17 26.7 1.174 2.157 172.5 3.4 20.2 2025 02 24 09 17.82 +18 08.6 1.188 2.147 160.9 8.7 20.2 2025 03 06 09 13.16 +18 37.9 1.224 2.140 149.7 13.5 20.2 2025 03 16 09 11.23 +18 51.4 1.281 2.135 139.2 17.7 20.3 2025 03 26 09 12.41 +18 48.4 1.353 2.132 129.6 21.1 20.4 2025 04 05 09 16.71 +18 29.3 1.439 2.132 120.8 23.8 20.6 2025 04 15 09 23.86 +17 55.1 1.535 2.134 112.8 25.7 20.7 2025 04 25 09 33.43 +17 07.3 1.639 2.139 105.4 27.0 20.9 2025 05 05 09 45.01 +16 06.8 1.748 2.146 98.7 27.7 21.0 2025 05 15 09 58.18 +14 55.1 1.862 2.155 92.4 27.9 21.2 2025 05 25 10 12.57 +13 33.3 1.978 2.167 86.5 27.8 21.3 2025 06 04 10 27.91 +12 02.5 2.096 2.181 81.0 27.3 21.5 2025 06 14 10 43.95 +10 24.1 2.215 2.197 75.7 26.6 21.6 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2025 CBAT 2025 February 28 (CBET 5516) Daniel W. E. Green