Electronic Telegram No. 5041 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/2016 U2 = P/2021 N4 (PANSTARRS) R. Weryk, Department of Physics and Astronomy, University of Western Ontario, has identified images of comet P/2014 N4 (cf. CBET 5019) in exposures obtained in 2016 with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala (astrometry tabulated below). Three 45-s w-band survey images taken on 2016 Oct. 25.5 UT in 1".2 seeing show a very condensed coma only slightly larger than stellar images (1".3 full-width-at-half-maximum) but with a short tail 3" long toward p.a. 220 degrees; the comet was too faint in the Nov. 15 i-band images to show any activity. 2016 UT R.A. (2000) Decl. Mag. Oct. 25.47090 1 55 03.16 +19 46 44.8 20.9 25.48345 1 55 02.55 +19 46 38.0 20.7 25.49596 1 55 01.95 +19 46 31.3 20.7 Nov. 15.41168 1 41 37.20 +16 38 07.1 21.4 15.42539 1 41 36.80 +16 38 00.1 21.4 15.45287 1 41 36.01 +16 37 45.9 21.6 The residuals for the 2016 observations were -2.9 deg in R.A. and -0.5 deg in Decl. from the orbit on CBET 5019, with a corresponding correction of Delta(T) = +6.3 days. The following linked orbital elements by S. Nakano (CBAT) are from 21 observations spanning 2016-2021 (mean residual 0".3); they indicate that the comet passed 2.78 AU from Jupiter on 2021 June 1 and will pass 2.45 AU and 1.93 AU from Jupiter on 2031 Mar. 29 and 2040 Oct. 10 UT, respectively. Epoch = 2016 May 12.0 TT T = 2016 May 19.48692 TT Peri. = 105.76385 e = 0.2418698 Node = 239.21870 2000.0 q = 2.3023083 AU Incl. = 10.07168 a = 3.0368245 AU n = 0.18624067 P = 5.29 years Epoch = 2021 Aug. 14.0 TT T = 2021 Aug. 30.63234 TT Peri. = 105.29934 e = 0.2425354 Node = 239.16338 2000.0 q = 2.3009640 AU Incl. = 10.06668 a = 3.0377183 AU n = 0.18615848 P = 5.29 years Epoch = 2026 Dec. 26.0 TT T = 2026 Dec. 15.30401 TT Peri. = 105.21569 e = 0.2406181 Node = 239.12126 2000.0 q = 2.3076246 AU Incl. = 10.06616 a = 3.0388197 AU n = 0.18605729 P = 5.30 years Epoch = 2032 Mar. 29.0 TT T = 2032 Apr. 1.15579 TT Peri. = 104.82136 e = 0.2368952 Node = 239.05972 2000.0 q = 2.3209442 AU Incl. = 10.06305 a = 3.0414487 AU n = 0.18581609 P = 5.30 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 18.0 and 2.5n = 7 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2021 08 14 23 08.09 +12 18.2 1.401 2.303 144.5 14.8 21.3 2021 08 24 23 02.92 +12 11.1 1.353 2.301 153.3 11.4 21.2 2021 09 03 22 56.44 +11 36.4 1.325 2.301 160.6 8.4 21.1 2021 09 13 22 49.65 +10 37.3 1.320 2.302 163.2 7.3 21.1 2021 09 23 22 43.69 +09 21.5 1.340 2.305 158.9 9.0 21.2 2021 10 03 22 39.50 +07 58.4 1.383 2.308 150.8 12.2 21.2 2021 10 13 22 37.73 +06 37.8 1.447 2.314 141.7 15.5 21.4 2021 10 23 22 38.69 +05 27.7 1.529 2.320 132.4 18.5 21.5 2021 11 02 22 42.35 +04 32.9 1.628 2.328 123.5 20.8 21.6 2021 11 12 22 48.51 +03 56.1 1.739 2.337 115.1 22.6 21.8 2021 11 22 22 56.87 +03 37.8 1.859 2.347 107.0 23.7 21.9 2021 12 02 23 07.08 +03 37.1 1.987 2.358 99.4 24.4 22.1 2021 12 12 23 18.86 +03 52.6 2.119 2.371 92.2 24.5 22.3 2021 12 22 23 31.89 +04 22.5 2.254 2.384 85.3 24.3 22.4 2022 01 01 23 45.95 +05 04.6 2.391 2.399 78.6 23.7 22.6 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2021 CBAT 2021 September 19 (CBET 5041) Daniel W. E. Green