Electronic Telegram No. 5200 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 R7 = P/2017 S9 = P/2011 Q5 (PANSTARRS) R. Weryk, Department of Physics and Astronomy, University of Western Ontario, reports the recovery of comet P/2017 S9 (cf. CBET 4448) in images obtained with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala on 2022 Aug. 6 and with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala on 2022 Sept. 2. He made the searches after discussions with H. Hsieh. The Sept. 2 images appear asteroidal, and the Aug. 6 images were not good enough to discern any activity reliably. 2022 UT R.A. (2000) Decl. Mag. Aug. 6.36410 21 43 29.67 -10 57 59.6 22.3 6.37554 21 43 29.21 -10 58 06.2 22.6 6.38699 21 43 28.73 -10 58 12.5 22.6 6.39851 21 43 28.27 -10 58 19.5 21.9 Sept. 2.37185 21 25 10.10 -15 35 14.2 22.7 2.38285 21 25 09.68 -15 35 20.5 22.1 2.39384 21 25 09.27 -15 35 27.1 22.7 2.40490 21 25 08.85 -15 35 33.7 23.1 Weryk was able to also identify Pan-STARRS1 images of the comet in 2011, with his astrometry tabulated below. The 2011 images also were not good enough to discern any activity reliably. 2011 UT R.A. (2000) Decl. Mag. Aug. 21.55796 23 56 12.38 - 8 27 29.6 23.1 21.56879 23 56 12.27 - 8 27 36.3 23.0 23.49537 23 55 49.76 - 8 49 23.7 21.5 23.51815 23 55 49.41 - 8 49 39.1 21.9 27.50761 23 54 46.58 - 9 36 30.6 22.2 27.52155 23 54 46.28 - 9 36 41.1 22.0 27.53550 23 54 45.97 - 9 36 51.2 22.2 27.54952 23 54 45.66 - 9 37 01.0 21.4 28.49131 23 54 27.95 - 9 48 22.2 21.0 28.50126 23 54 27.74 - 9 48 30.0 21.2 Sept. 7.50278 23 50 18.07 -11 53 01.5 22.2 7.51501 23 50 17.68 -11 53 10.5 22.0 The available astrometry appears on MPEC 2022-Y14. The residuals for the recovery observations on 2022 Aug. 6 from the prediction based on the 2017 observations (NK 4285) were +0.29 deg in R.A. and +0.03 deg in Decl., with a corresponding correction of Delta(T) = -0.69 day. The following linked orbital elements by S. Nakano (Central Bureau) are from 70 observations spanning 2011-2022 (mean residual 0".3). There are no close approaches to major planets, and Nakano was unable to identify any additional observations in archival data. Epoch = 2011 Dec. 25.0 TT T = 2011 Dec. 19.54334 TT Peri. = 238.27081 e = 0.3049760 Node = 146.26882 2000.0 q = 2.1934173 AU Incl. = 14.13518 a = 3.1558869 AU n = 0.17580123 P = 5.61 years Epoch = 2017 July 26.0 TT T = 2017 July 23.63636 TT Peri. = 237.93077 e = 0.3042585 Node = 146.20988 2000.0 q = 2.1952030 AU Incl. = 14.13755 a = 3.1551991 AU n = 0.17585872 P = 5.60 years Epoch = 2023 Feb. 25.0 TT T = 2023 Feb. 25.46800 TT Peri. = 237.56524 e = 0.3053851 Node = 146.20510 2000.0 q = 2.1916918 AU Incl. = 14.13775 a = 3.1552618 AU n = 0.17585348 P = 5.60 years Epoch = 2028 Sept.26.0 TT T = 2028 Oct. 1.39273 TT Peri. = 237.41041 e = 0.3038013 Node = 146.16561 2000.0 q = 2.1974829 AU Incl. = 14.13224 a = 3.1564017 AU n = 0.17575823 P = 5.61 years Epoch = 2034 Apr. 28.0 TT T = 2034 May 7.73546 TT Peri. = 236.90073 e = 0.3029178 Node = 146.13783 2000.0 q = 2.2018211 AU Incl. = 14.13176 a = 3.1586250 AU n = 0.17557269 P = 5.61 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 16.5 and 2.5n = 10 for the magnitudes. The data suggest that the comet's instrinic brightness may be about 1 mag brighter post-perihelion than pre-perihelion (the 2011 and 2022 observations are all pre-perihelion, and the 2017 observations are all post-perihelion). The comet is close to the sun for much of 2023. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2022 12 07 22 19.67 -17 52.3 2.279 2.251 75.8 25.1 21.8 2022 12 17 22 35.57 -16 42.5 2.379 2.237 69.7 24.4 21.9 2022 12 27 22 52.41 -15 21.5 2.475 2.226 63.9 23.4 21.9 2023 01 06 23 09.98 -13 50.8 2.567 2.215 58.4 22.2 22.0 2023 01 16 23 28.14 -12 12.0 2.654 2.207 53.0 20.9 22.1 2023 01 26 23 46.77 -10 26.5 2.736 2.200 47.9 19.4 22.1 2023 02 05 00 05.79 -08 35.9 2.811 2.196 43.0 17.8 22.2 2023 02 15 00 25.13 -06 41.8 2.882 2.193 38.2 16.2 22.2 2023 02 25 00 44.74 -04 45.8 2.946 2.192 33.6 14.5 22.3 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2022 CBAT 2022 December 17 (CBET 5200) Daniel W. E. Green