Electronic Telegram No. 5166 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 M1 = P/2000 OZ_21 (LONEOS-PANSTARRS) Further to CBET 5146, S. Nakano (Central Bureau) has identified an apparently asteroidal object discovered by the LONEOS survey on 2000 July 29 (and observed only over a five-day arc then; designated 2000 OZ_21 when announced on MPS 17842) with comet P/2022 M1. The LONEOS discovery observations are tabulated below. 2000 UT R.A. (2000) Decl. Mag. July 29.36467 21 23 13.61 -20 38 37.4 18.4 29.38400 21 23 12.99 -20 38 34.6 29.40332 21 23 12.38 -20 38 34.8 29.42267 21 23 11.67 -20 38 30.5 The orbital elements from the short five-day arc in 2000 were T = 2000 Sept. 5, q = 2.08 AU, e = 0.57, Peri. = 347 deg, Node = 340 deg, i = 5 deg, a = 4.87 AU (cf. MPO 3953). An updated orbit by Nakano for the 2022 observations (through 2022 Aug. 25) showed residuals of -3.3 deg in R.A. and -1.4 deg in Decl. for the 2000 observations, with a corresponding correction of Delta(T) = -4.6 days. Nakano provides the following linked orbital elements from 107 observations spanning 2000-2022 (mean residual 0".5). These indicate that the comet passed 0.49 AU from Jupiter on 2013 Oct. 7 and 2.84 AU from Saturn on 2007 May 3 UT. Epoch = 2000 Sept.13.0 TT T = 2000 Sept. 8.47012 TT Peri. = 348.31385 e = 0.5784070 Node = 340.12424 2000.0 q = 2.0886709 AU Incl. = 5.60581 a = 4.9542353 AU n = 0.08937975 P = 11.03 years Epoch = 2011 Nov. 15.0 TT T = 2011 Oct. 29.46698 TT Peri. = 350.02942 e = 0.5801646 Node = 339.39820 2000.0 q = 2.0856514 AU Incl. = 5.65049 a = 4.9677836 AU n = 0.08901436 P = 11.07 years Epoch = 2022 Aug. 9.0 TT T = 2022 Aug. 2.38037 TT Peri. = 4.46891 e = 0.5783720 Node = 322.92153 2000.0 q = 2.0614042 AU Incl. = 7.02693 a = 4.8891541 AU n = 0.09117032 P = 10.81 years Epoch = 2033 Mar. 24.0 TT T = 2033 Mar. 20.19339 TT Peri. = 3.42408 e = 0.5782050 Node = 322.55163 2000.0 q = 2.0518894 AU Incl. = 7.05029 a = 4.8646607 AU n = 0.09185975 P = 10.73 years Epoch = 2043 Nov. 7.0 TT T = 2043 Nov. 21.38232 TT Peri. = 2.85247 e = 0.5736797 Node = 321.78013 2000.0 q = 2.0910777 AU Incl. = 6.90617 a = 4.9049452 AU n = 0.09073040 P = 10.86 years The IAU's Working Group on Small Bodies Nomenclature has thus changed the name of this comet from "PANSTARRS" to "LONEOS-PANSTARRS". The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 15.5 and 2.5n = 10 for the magnitudes, which is a half-magnitude brighter in absolute magnitude from what was used on CBET 5146 (to reflect slightly brighter astrometric magnitudes over the past couple of months); the comet was about 1 magnitude brighter than these parameters would indicate in 2000. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 09 18 22 34.47 -03 16.9 1.122 2.104 163.4 7.8 19.0 2022 09 28 22 31.40 -02 58.2 1.181 2.124 153.3 12.3 19.1 2022 10 08 22 30.82 -02 35.8 1.260 2.148 143.6 16.0 19.3 2022 10 18 22 32.91 -02 07.2 1.357 2.175 134.4 19.1 19.5 2022 10 28 22 37.57 -01 30.8 1.470 2.205 125.9 21.4 19.8 2022 11 07 22 44.57 -00 45.7 1.595 2.237 117.9 23.1 20.0 2022 11 17 22 53.55 +00 08.1 1.732 2.273 110.3 24.1 20.3 2022 11 27 23 04.15 +01 10.1 1.877 2.311 103.1 24.6 20.5 2022 12 07 23 16.08 +02 19.6 2.030 2.351 96.3 24.6 20.7 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 September 3 (CBET 5166) Daniel W. E. Green