Electronic Telegram No. 5164 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 Q1 = P/2015 X1 = P/2008 T13 (PANSTARRS) Erwin Schwab, Egelsbach, Germany, reports his recovery of comet P/2015 X1 (cf. CBET 4212) on CCD images taken remotely on two nights with the 0.8-m f/3 Schmidt reflector at Calar Alto, Spain, in a program with D. Koschny, M. Micheli, and R. Kresken; on each night, sets of twelve 60-s CCD exposures show no tail and no coma. The recovery astrometry is tabulated below. 2022 UT R.A. (2000) Decl. Mag. Observer Aug. 23.08953 2 47 40.91 + 6 49 12.0 21.0 Schwab 23.10197 2 47 41.77 + 6 49 09.2 21.0 " 23.11441 2 47 42.63 + 6 49 06.9 21.2 " 24.08953 2 48 51.08 + 6 45 26.1 20.9 " 24.10197 2 48 51.93 + 6 45 23.6 21.0 " 24.11441 2 48 52.77 + 6 45 20.5 21.1 " The residuals for the above recovery observations are +27" in R.A. and +5" in Decl. from the prediction by S. Nakano (Central Bureau) in NK 3986, with a corresponding correction of Delta(T) = -0.016 day. Nakano used an orbit linking the 2015-2022 to find two previously unlinked nigts of observations that he found in the Minor Planet Center's "isolated tracklet file" that were made in 2008 by the Catalina Sky Survey, with those observations tabulated below; the 2015-2022 orbit reveals only small residuals in the 2008 data, with essentially no Delta(T) correction needed. 2008 UT R.A. (2000) Decl. Mag. Oct. 1.37698 0 22 58.76 - 7 32 30.5 20.0 1.38512 0 22 58.44 - 7 32 35.3 19.9 1.39329 0 22 58.08 - 7 32 43.6 19.0 1.40147 0 22 57.86 - 7 32 48.7 19.8 Dec. 31.11418 1 02 39.26 - 6 16 13.3 18.9 31.12264 1 02 39.76 - 6 16 10.2 19.8 31.13120 1 02 40.52 - 6 16 04.6 19.5 31.13973 1 02 41.06 - 6 16 00.9 19.6 Nakano provides the following linked orbital elements from 96 observations made at the three known apparitions, 2008-2022 (mean residual 0".4). These suggest that the comet passed 0.59 AU from Jupiter on 2005 Jan. 20 UT. Epoch = 2008 Oct. 21.0 TT T = 2008 Nov. 9.31841 TT Peri. = 218.75678 e = 0.4214720 Node = 161.88730 2000.0 q = 2.0958384 AU Incl. = 12.17604 a = 3.6227088 AU n = 0.14294005 P = 6.90 years Epoch = 2015 Oct. 25.0 TT T = 2015 Oct. 10.68105 TT Peri. = 219.03191 e = 0.4204003 Node = 161.79100 2000.0 q = 2.1035377 AU Incl. = 12.16213 a = 3.6292942 AU n = 0.14255118 P = 6.91 years Epoch = 2022 Sept.18.0 TT T = 2022 Sept. 6.59931 TT Peri. = 218.74067 e = 0.4192318 Node = 161.75746 2000.0 q = 2.1120590 AU Incl. = 12.15176 a = 3.6366643 AU n = 0.14211806 P = 6.94 years Epoch = 2029 Aug. 12.0 TT T = 2029 Aug. 13.08845 TT Peri. = 218.67863 e = 0.4176288 Node = 161.73507 2000.0 q = 2.1208304 AU Incl. = 12.13959 a = 3.6417156 AU n = 0.14182246 P = 6.95 years Epoch = 2036 July 6.0 TT T = 2036 July 20.83278 TT Peri. = 218.71628 e = 0.4192368 Node = 161.71783 2000.0 q = 2.1096129 AU Incl. = 12.15077 a = 3.6324839 AU n = 0.14236346 P = 6.92 years 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 (based on observations at the 2008 and 2015 returns). Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 08 09 02 29.22 +07 22.1 1.719 2.123 98.7 28.2 19.9 2022 08 19 02 42.69 +07 02.6 1.615 2.117 105.1 27.5 19.8 2022 08 29 02 54.28 +06 24.2 1.516 2.113 112.0 26.3 19.7 2022 09 08 03 03.59 +05 26.9 1.427 2.112 119.4 24.6 19.5 2022 09 18 03 10.24 +04 12.1 1.348 2.114 127.3 22.2 19.4 2022 09 28 03 13.92 +02 43.0 1.282 2.118 135.7 19.3 19.3 2022 10 08 03 14.52 +01 05.3 1.232 2.126 144.4 15.9 19.2 2022 10 18 03 12.26 -00 32.6 1.201 2.136 152.7 12.4 19.2 2022 10 28 03 07.71 -02 00.7 1.191 2.148 158.9 9.6 19.2 2022 11 07 03 01.89 -03 08.7 1.204 2.163 160.4 8.8 19.3 2022 11 17 02 55.99 -03 49.0 1.240 2.181 156.0 10.6 19.4 2022 11 27 02 51.13 -03 58.6 1.298 2.201 148.4 13.6 19.5 2022 12 07 02 48.20 -03 38.1 1.377 2.223 139.9 16.6 19.7 2022 12 17 02 47.70 -02 52.2 1.473 2.247 131.2 19.2 19.9 2022 12 27 02 49.74 -01 46.2 1.585 2.273 122.8 21.3 20.1 2023 01 06 02 54.27 -00 26.0 1.709 2.301 114.8 22.8 20.3 2023 01 16 03 01.03 +01 03.4 1.842 2.331 107.2 23.8 20.5 2023 01 26 03 09.76 +02 37.6 1.983 2.362 100.0 24.2 20.7 2023 02 05 03 20.17 +04 13.3 2.130 2.395 93.1 24.3 20.9 2023 02 15 03 32.00 +05 47.7 2.280 2.428 86.5 23.9 21.1 2023 02 25 03 45.03 +07 18.6 2.432 2.464 80.1 23.3 21.3 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 August 28 (CBET 5164) Daniel W. E. Green