Electronic Telegram No. 5115 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 G1 = P/2011 Q3 (McNAUGHT) H. Sato, Bunkyo-ku, Tokyo, Japan, reports his recovery of comet P/2011 Q3 (cf. CBET 2803, IAUC 9229) in CCD images obtained remotely with a 0.51-m f/6.8 astrograph located at Siding Spring, NSW, Australia (recovery observations tabulated below). Sato notes that the comet appeared stellar on stacks of 60-s exposures on each night (twelve exposuers on Apr. 5 and 11, and seven on Apr. 10). The magnitude on Apr. 5 was measured within a circular aperture of radius 6".6; the magnitudes for Apr. 10 and 11 were measured within a circular aperture of radius 4".9. 2022 UT R.A. (2000) Decl. Mag. Observer Apr. 5.79152 21 31 03.16 -20 13 07.4 Sato 5.79705 21 31 03.75 -20 13 04.6 20.0 " 10.75771 21 39 52.41 -19 36 24.2 " 10.76114 21 39 52.77 -19 36 22.6 20.5 " 11.78503 21 41 41.00 -19 28 43.4 " 11.79008 21 41 41.51 -19 28 41.3 20.1 " The residuals were +15" in R.A. and +3" in Decl. from the prediction in NK 2201 and the ICQ's 2021 Comet Handbook, with the corresponding correction of Delta(T) = -0.02 day. S. Nakano (Central Bureau) then linked the 2011 and 2022 apparitions of this comet and found an undesignated (and presumably asteroidal) object observed via the Spacewatch program of Steward Observatory on a single night at Kitt Peak in archival data (observations tabulated below) having residuals of -16" and -2" with respect to his linked orbit, and a corresponding Delta(T) correction of only -0.014 day. 2000 UT R.A. (2000) Decl. Mag. Nov. 28.20878 2 44 01.05 +15 13 36.5 21.9 28.24076 2 43 59.92 +15 13 36.4 21.6 28.27098 2 43 58.93 +15 13 36.9 21.8 The following linked orbital elements by Nakano covering the three apparitions are from 156 observations spanning 2000-2022 (mean residual 0".6). These indicate that the comet passed 0.75 AU and 0.53 AU from Jupiter on 1990 July 30 and 2002 Apr. 9 UT, respectively; due to these approaches, the 1988 orbit was somewhat changed. Epoch = 1988 Oct. 6.0 TT T = 1988 Sept.19.99343 TT Peri. = 284.63254 e = 0.5323533 Node = 60.07435 2000.0 q = 2.3152190 AU Incl. = 7.46930 a = 4.9507864 AU n = 0.08947316 P = 11.02 years Epoch = 2000 Apr. 6.0 TT T = 2000 Apr. 17.95027 TT Peri. = 293.52286 e = 0.5278906 Node = 54.22483 2000.0 q = 2.4125604 AU Incl. = 6.93629 a = 5.1101719 AU n = 0.08531999 P = 11.55 years Epoch = 2011 Aug. 27.0 TT T = 2011 Aug. 14.33779 TT Peri. = 310.24219 e = 0.5313772 Node = 35.31554 2000.0 q = 2.3679137 AU Incl. = 6.05256 a = 5.0529201 AU n = 0.08677416 P = 11.36 years Epoch = 2022 Aug. 9.0 TT T = 2022 Aug. 19.16746 TT Peri. = 310.98480 e = 0.5333985 Node = 32.01908 2000.0 q = 2.3225275 AU Incl. = 6.05796 a = 4.9775398 AU n = 0.08875278 P = 11.10 years Epoch = 2033 July 22.0 TT T = 2033 July 24.20556 TT Peri. = 310.11354 e = 0.5324946 Node = 31.15189 2000.0 q = 2.3232893 AU Incl. = 6.09437 a = 4.9695448 AU n = 0.08896704 P = 11.08 years Epoch = 2044 Aug. 13.0 TT T = 2044 July 29.16826 TT Peri. = 309.08544 e = 0.5262871 Node = 30.35587 2000.0 q = 2.3796732 AU Incl. = 6.10139 a = 5.0234497 AU n = 0.08753888 P = 11.26 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 (from the 2011 apparition CCD astrometry magnitudes). Sato's Apr. 2022 magnitudes are 0.5-1.0 mag fainter, but the comet was not seen as far out as r = 2.55 AU pre-perihelion in 2011 (it was discovered just after perihelion at r = 2.37 AU that year). Date TT R. A. (2000) Decl. Delta r Elong. Phase Nag. 2022 04 11 21 40.30 -19 34.6 2.899 2.552 60.1 19.9 19.4 2022 04 21 21 57.66 -18 18.9 2.765 2.520 65.5 21.3 19.2 2022 05 01 22 14.43 -17 01.8 2.629 2.490 71.0 22.5 19.1 2022 05 11 22 30.52 -15 45.0 2.492 2.462 76.6 23.5 18.9 2022 05 21 22 45.82 -14 29.8 2.357 2.437 82.3 24.3 18.7 2022 05 31 23 00.19 -13 17.9 2.223 2.414 88.2 24.8 18.6 2022 06 10 23 13.47 -12 11.0 2.093 2.393 94.3 25.0 18.4 2022 06 20 23 25.48 -11 10.8 1.967 2.375 100.6 24.9 18.2 2022 06 30 23 35.97 -10 18.9 1.846 2.359 107.4 24.3 18.1 2022 07 10 23 44.66 -09 37.0 1.733 2.346 114.6 23.2 17.9 2022 07 20 23 51.31 -09 06.1 1.629 2.336 122.3 21.6 17.7 2022 07 30 23 55.61 -08 47.0 1.536 2.328 130.6 19.3 17.6 2022 08 09 23 57.38 -08 39.4 1.457 2.324 139.6 16.4 17.5 2022 08 19 23 56.59 -08 41.4 1.395 2.323 149.1 12.9 17.4 2022 08 29 23 53.44 -08 50.0 1.352 2.324 159.1 8.9 17.3 2022 09 08 23 48.49 -09 00.5 1.332 2.328 168.8 4.8 17.3 2022 09 18 23 42.61 -09 07.1 1.335 2.336 172.9 3.0 17.3 2022 09 28 23 36.81 -09 05.0 1.362 2.346 165.3 6.2 17.4 2022 10 08 23 32.11 -08 50.4 1.414 2.358 155.2 10.3 17.5 2022 10 18 23 29.29 -08 21.7 1.487 2.374 145.1 13.9 17.6 2022 10 28 23 28.76 -07 38.9 1.580 2.392 135.4 16.9 17.8 2022 11 07 23 30.66 -06 43.0 1.690 2.413 126.3 19.3 18.0 2022 11 17 23 34.89 -05 35.7 1.814 2.436 117.7 21.1 18.2 2022 11 27 23 41.21 -04 18.9 1.949 2.462 109.6 22.2 18.4 2022 12 07 23 49.36 -02 54.0 2.092 2.489 101.9 22.8 18.6 2022 12 17 23 59.02 -01 22.8 2.242 2.519 94.5 22.9 18.8 2022 12 27 00 09.96 +00 13.4 2.397 2.551 87.5 22.7 19.0 2023 01 06 00 21.94 +01 53.2 2.554 2.584 80.7 22.1 19.2 2023 01 16 00 34.76 +03 35.3 2.711 2.619 74.1 21.2 19.3 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 April 18 (CBET 5115) Daniel W. E. Green