Electronic Telegram No. 5177 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 S2 = P/2007 A2 (CHRISTENSEN) Erwin Schwab, Egelsbach, Germany, reports his recovery of comet P/2007 A2 (cf. IAUCs 8794, 8796) on CCD images taken on two nights remotely with the 0.8-m f/3 Schmidt reflector at Calar Alto, Spain. Twelve stacked 60-s exposures show no tail and no coma on each of the two nights. R. Kresken and M. Micheli were also involved in the recovery. Schwab's astrometry is tabulated below. 2022 UT R.A. (2000) Decl. Mag. Observer Sept.27.17130 8 51 05.35 +21 20 18.3 21.0 Schwab 27.18063 8 51 06.07 +21 20 11.8 20.6 " 27.18996 8 51 06.92 +21 20 05.5 20.5 " Oct. 1.17130 8 56 36.58 +20 36 35.9 20.8 " 1.18063 8 56 37.25 +20 36 30.2 20.8 " 1.18996 8 56 38.04 +20 36 23.5 20.9 " The residuals for the recovery observations were +12'.7 in R.A. and -11'.9 in Decl. from the prediction on NK 1669, with a corresponding correctiono of Delta(T) = -1.33 days. The following linked orbital elements by S. Nakano (Central Bureau) are from 103 observations spanning 2006-2022 (mean residual 0".6), and they suggest no close approaches to major planets in the past. Nakano was unable to find any additional observations in past archival data. Epoch = 2007 Jan. 20.0 TT T = 2007 Jan. 17.89527 TT Peri. = 186.98349 e = 0.5585053 Node = 301.04499 2000.0 q = 2.7962904 AU Incl. = 26.49007 a = 6.3336902 AU n = 0.06183279 P = 15.94 years Epoch = 2022 Dec. 7.0 TT T = 2022 Nov. 27.53226 TT Peri. = 186.69619 e = 0.5583939 Node = 300.91269 2000.0 q = 2.7985037 AU Incl. = 26.48294 a = 6.3371042 AU n = 0.06178283 P = 15.95 years Epoch = 2038 Dec. 3.0 TT T = 2038 Dec. 6.66869 TT Peri. = 186.56851 e = 0.5605402 Node = 300.89476 2000.0 q = 2.8132600 AU Incl. = 26.41550 a = 6.4016317 AU n = 0.06085105 P = 16.20 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 13.0 and 2.5n = 10 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 09 18 08 37.86 +22 57.6 3.407 2.850 49.0 15.4 20.2 2022 09 28 08 52.24 +21 11.3 3.290 2.837 55.0 16.8 20.1 2022 10 08 09 05.65 +19 20.4 3.167 2.825 61.2 18.1 20.0 2022 10 18 09 17.99 +17 25.5 3.038 2.816 67.8 19.1 19.9 2022 10 28 09 29.12 +15 27.2 2.905 2.808 74.6 19.9 19.8 2022 11 07 09 38.86 +13 26.4 2.769 2.803 81.7 20.5 19.7 2022 11 17 09 47.05 +11 23.8 2.634 2.800 89.2 20.7 19.6 2022 11 27 09 53.45 +09 20.5 2.500 2.799 97.1 20.5 19.5 2022 12 07 09 57.85 +07 17.7 2.371 2.799 105.5 19.8 19.3 2022 12 17 10 00.03 +05 16.7 2.250 2.802 114.3 18.7 19.2 2022 12 27 09 59.81 +03 19.6 2.141 2.808 123.6 17.0 19.1 2023 01 06 09 57.11 +01 28.9 2.048 2.815 133.3 14.7 19.1 2023 01 16 09 52.08 -00 12.7 1.975 2.824 143.1 12.1 19.0 2023 01 26 09 45.04 -01 41.7 1.925 2.835 152.5 9.2 18.9 2023 02 05 09 36.68 -02 55.5 1.902 2.849 160.0 6.8 18.9 2023 02 15 09 27.87 -03 52.7 1.908 2.864 162.1 6.1 19.0 2023 02 25 09 19.56 -04 33.5 1.942 2.881 157.5 7.5 19.0 2023 03 07 09 12.64 -05 00.3 2.002 2.900 149.4 10.0 19.1 2023 03 17 09 07.70 -05 16.8 2.086 2.921 140.2 12.6 19.3 2023 03 27 09 05.09 -05 27.3 2.190 2.943 131.0 14.8 19.4 2023 04 06 09 04.88 -05 35.8 2.311 2.967 122.2 16.6 19.5 2023 04 16 09 06.94 -05 45.6 2.444 2.993 113.7 17.9 19.7 2023 04 26 09 11.06 -05 59.2 2.587 3.020 105.8 18.7 19.9 2023 05 06 09 16.98 -06 18.3 2.735 3.048 98.3 19.1 20.0 2023 05 16 09 24.42 -06 44.0 2.888 3.078 91.1 19.2 20.2 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 October 8 (CBET 5177) Daniel W. E. Green