Electronic Telegram No. 5078 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/2008 WZ_96 = P/2021 W1 (LINEAR) E. Schwab, Egelsbach, Germany, reports his recovery of comet P/2008 WZ_96 (cf. IAUC 9015) on two sets twelve 60-s CCD exposures taken on two nights each with a 0.8-m f/3 Schmidt telescope at Calar Alto as part of a program with D. Koschny, M. Micheli, and E. Petrescu; the comet's head has a size of 3".3 (full-width-at-half-maximum) in 2".7 seeing, with no tail. 2021 UT R.A. (2000) Decl. Mag. Observer Nov. 30.02694 6 14 43.64 +28 56 31.8 Schwab 30.03921 6 14 43.11 +28 56 37.0 19.8 " 30.05149 6 14 42.61 +28 56 41.7 " Dec. 1.19362 6 13 54.45 +29 03 36.7 19.6 " 1.20590 6 13 53.89 +29 03 40.6 19.6 " 1.21818 6 13 53.34 +29 03 45.1 19.5 " The residuals for the recovery observations are -65" in R.A. and -6" in Decl. from the prediction in NK 3673 and the ICQ's 2020 and 2021 Comet Handbooks, with a corresponding correction of Delta(T) = +0.026 day. The following linked orbital elements by S. Nakano (CBAT) are from 136 observations spanning 2008-2021 (mean residual 0".5). The comet passed 0.35 AU from Jupiter on 2006 Apr. 8 (which caused some change in the orbit) and 0.81 AU from Jupiter on 2017 Oct. 9 UT. The comet was missed at its 2015 return. Epoch = 2002 Mar. 27.0 TT T = 2002 Mar. 15.43620 TT Peri. = 318.24904 e = 0.4442286 Node = 72.17501 2000.0 q = 2.0056512 AU Incl. = 5.12784 a = 3.6087702 AU n = 0.14376899 P = 6.86 years Epoch = 2009 Jan. 9.0 TT T = 2009 Jan. 23.91074 TT Peri. = 337.62047 e = 0.5096327 Node = 59.11122 2000.0 q = 1.6462656 AU Incl. = 6.95777 a = 3.3572093 AU n = 0.16022727 P = 6.15 years Epoch = 2015 Apr. 8.0 TT T = 2015 Mar. 25.17786 TT Peri. = 337.81920 e = 0.5095990 Node = 59.05061 2000.0 q = 1.6469653 AU Incl. = 6.95821 a = 3.3584051 AU n = 0.16014171 P = 6.16 years Epoch = 2021 Aug. 14.0 TT T = 2021 Aug. 26.06333 TT Peri. = 341.98153 e = 0.4693701 Node = 56.41790 2000.0 q = 1.8502096 AU Incl. = 7.11459 a = 3.4868177 AU n = 0.15137711 P = 6.51 years Epoch = 2028 Mar. 10.0 TT T = 2028 Mar. 6.14910 TT Peri. = 342.11889 e = 0.4683986 Node = 56.38225 2000.0 q = 1.8567447 AU Incl. = 7.10939 a = 3.4927382 AU n = 0.15099238 P = 6.53 years Epoch = 2034 Oct. 5.0 TT T = 2034 Sept.17.37417 TT Peri. = 341.97769 e = 0.4655930 Node = 56.32637 2000.0 q = 1.8727423 AU Incl. = 7.10073 a = 3.5043369 AU n = 0.15024336 P = 6.56 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 14.0 and 2.5n = 15 for the magnitudes, splitting the somewhat-discordant magnitudes at the 2008-2009 and the 2021 apparitions (the comet perhaps undergoing an outburst at the discovery return). Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2021 11 22 06 19.07 +28 06.0 1.105 1.997 145.1 16.4 18.7 2021 12 02 06 13.33 +29 08.5 1.088 2.029 156.1 11.3 18.8 2021 12 12 06 04.81 +30 03.2 1.093 2.064 167.0 6.1 18.9 2021 12 22 05 55.18 +30 44.6 1.122 2.101 172.6 3.5 19.1 2022 01 01 05 46.25 +31 10.6 1.176 2.141 164.7 7.0 19.3 2022 01 11 05 39.57 +31 22.6 1.255 2.181 154.0 11.4 19.6 2022 01 21 05 36.10 +31 24.5 1.355 2.224 143.5 15.3 19.9 2022 01 31 05 36.11 +31 20.1 1.474 2.268 133.5 18.4 20.2 2022 02 10 05 39.48 +31 12.3 1.608 2.313 124.3 20.6 20.5 2022 02 20 05 45.83 +31 02.3 1.755 2.358 115.7 22.2 20.8 2022 03 02 05 54.65 +30 50.6 1.912 2.405 107.6 23.1 21.1 2022 03 12 06 05.50 +30 36.6 2.076 2.452 100.0 23.5 21.4 2022 03 22 06 17.94 +30 19.6 2.245 2.500 92.8 23.4 21.7 2022 04 01 06 31.61 +29 59.0 2.416 2.549 86.0 23.0 22.0 2022 04 11 06 46.21 +29 34.1 2.588 2.597 79.4 22.3 22.3 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2021 CBAT 2021 December 3 (CBET 5078) Daniel W. E. Green