Electronic Telegram No. 5100 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/2022 B2 = P/2017 R1 (PANSTARRS) M. Rudenko, Minor Planet Center, writes on MPEC 2022-D03 that the MPC has identified CCD observations on two nights of comet P/2017 R1 as an apparently asteroidal object (cf. CBET 4430) in its "isolated tracklet file": from images taken on Jan. 25 by K. W. Wierzchos with the Mt. Lemmon 1.5-m reflector and on Feb. 10 with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala, with the astrometry tabulated below. 2022 UT R.A. (2000) Decl. Mag. Observer Jan. 25.51151 11 15 10.84 + 5 44 07.0 22.1 Wierzchos 25.51663 11 15 10.70 + 5 44 07.9 20.9 " 25.52175 11 15 10.61 + 5 44 08.5 20.8 " 25.52686 11 15 10.48 + 5 44 09.9 21.1 " Feb. 10.50034 11 09 05.59 + 6 29 00.7 21.0 Pan-STARRS2 10.51134 11 09 05.28 + 6 29 03.0 21.0 " 10.52226 11 09 04.96 + 6 29 05.2 21.0 " 10.53325 11 09 04.65 + 6 29 07.1 20.9 " The residuals for the recovery observations are +32" in R.A. and -12" in Decl. from the prediction in NK 4192, with a corresponding Delta(T) correction of -0.10 day. The following linked orbital elements by S. Nakano (CBAT) are from 79 observations spanning 2017-2022 (mean residual 0".4) and indicate that the comet passed 0.048 AU from Jupiter on 1979 June 23 UT. Prior to that close approach, the comet had an orbit with T = 1978 Oct. 21.3 TT, q = 5.354 AU, e = 0.262, Peri. = 91.6 deg, Node = 22.3 deg, i = 2.1 deg, a = 7.259 AU, P = 19.6 years. Epoch = 2008 Nov. 30.0 TT T = 2008 Nov. 27.44406 TT Peri. = 179.16370 e = 0.1966695 Node = 143.64284 2000.0 q = 3.3225065 AU Incl. = 2.57248 a = 4.1359150 AU n = 0.11717816 P = 8.41 years Epoch = 2017 Mar. 28.0 TT T = 2017 Apr. 8.22170 TT Peri. = 178.38204 e = 0.1945496 Node = 143.65324 2000.0 q = 3.3273749 AU Incl. = 2.57341 a = 4.1310734 AU n = 0.11738422 P = 8.40 years Epoch = 2025 Sept. 2.0 TT T = 2025 Sept. 9.45705 TT Peri. = 178.86637 e = 0.1945599 Node = 143.59127 2000.0 q = 3.3279217 AU Incl. = 2.57486 a = 4.1318052 AU n = 0.11735303 P = 8.40 years Epoch = 2033 Dec. 29.0 TT T = 2034 Jan. 17.56355 TT Peri. = 178.01980 e = 0.1969807 Node = 143.59035 2000.0 q = 3.3188928 AU Incl. = 2.57666 a = 4.1330173 AU n = 0.11730141 P = 8.40 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 13.0 and 2.5n = 7.5 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 01 21 11 16.37 +05 34.7 4.170 4.892 132.8 8.5 21.3 2022 02 10 11 09.32 +06 27.4 3.969 4.882 155.1 4.9 21.2 2022 03 02 10 58.92 +07 39.2 3.880 4.870 177.8 0.4 21.1 2022 03 22 10 48.03 +08 50.7 3.915 4.858 159.0 4.2 21.1 2022 04 11 10 39.75 +09 43.0 4.064 4.845 137.0 8.1 21.2 2022 05 01 10 36.11 +10 05.3 4.296 4.831 116.5 10.8 21.3 2022 05 21 10 37.69 +09 55.8 4.576 4.816 97.6 12.0 21.4 2022 06 10 10 44.04 +09 17.4 4.869 4.801 80.1 12.0 21.5 2022 06 30 10 54.31 +08 14.8 5.145 4.784 63.8 11.0 21.7 2022 07 20 11 07.57 +06 52.9 5.382 4.767 48.3 9.2 21.7 2022 12 07 13 06.04 -05 17.1 5.078 4.621 57.3 10.3 21.5 2022 12 27 13 18.92 -06 25.7 4.765 4.597 74.2 11.9 21.4 2023 01 16 13 28.19 -07 09.0 4.427 4.572 92.2 12.4 21.2 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 February 16 (CBET 5100) Daniel W. E. Green