Electronic Telegram No. 5694 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 C/2026 J1 (PANSTARRS) R. Weryk, Department of Physics and Astronomy, University of Western Ontario, reports the discovery of another comet in images obtained with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala on May 14 (discovery observations tabulted below). Two stacked 45-s w-band survey images taken in 1".4 seeing show a condensed head of size 1".8 (full-width-at-half-maximum) with no tail. 2026 UT R.A. (2000) Decl. Mag. May 14.56849 18 22 25.57 +58 01 07.8 20.4 14.58221 18 22 24.15 +58 01 05.2 20.3 14.59595 18 22 22.73 +58 01 02.6 20.1 Three stacked 60-s gri-band follow-up observations obtained by Weryk and R. Wainscoat with the 3.6-m Canada-France-Hawaii Telescope at Mauna Kea on May 21.4 UT (queue observer J. Silva; queue coordinator J. Ou) in 0".6-0".7 seeing show a condensed head of size 1".0 and an 8" tail spanning p.a. 210-250 deg. After the object was posted to the Minor Planet Center's NEOCP webpage, H. Sato (Bunkyo-ku, Tokyo, Japan) obtained eighteen stacked 60-s CCD exposures with an iTelescope 0.43-m f/6.8 astrograph located at the Utah Desert Remote Observatory (near Beryl Junction, UT, USA) on May 15.45 UT that show only a stellar appearance; the magnitude was 19.6 as measured within a circular aperture of radius 5".7. The available astrometry appears on MPEC 2026-K105. The following two-body elliptical orbital elements by S. Nakano (Central Bureau) are from 172 observations spanning 2026 May 14-26 (mean residual 0".3). The comet passed 3.76 AU from Jupiter on 2025 Mar. 18 UT. T = 2026 June 30.26891 TT Peri. = 129.48574 e = 0.9005629 Node = 100.35929 2000.0 q = 2.5239532 AU Incl. = 73.11468 a = 25.3824214 AU n = 0.00770734 P = 127.9 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 14.0 and 2.5n = 8 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2026 04 30 18 42.22 +58 09.6 2.385 2.601 90.7 22.8 19.2 2026 05 10 18 29.71 +58 11.1 2.310 2.578 93.6 23.0 19.1 2026 05 20 18 12.68 +57 38.0 2.236 2.559 96.7 23.1 19.0 2026 05 30 17 52.51 +56 16.6 2.166 2.544 99.9 23.1 18.9 2026 06 09 17 31.33 +53 56.1 2.104 2.533 103.0 23.0 18.8 2026 06 19 17 11.37 +50 30.9 2.056 2.527 105.6 22.8 18.8 2026 06 29 16 54.46 +46 03.3 2.027 2.524 107.4 22.6 18.8 2026 07 09 16 41.52 +40 43.8 2.021 2.526 107.9 22.5 18.7 2026 07 19 16 32.71 +34 48.0 2.042 2.531 106.9 22.6 18.8 2026 07 29 16 27.76 +28 34.6 2.091 2.541 104.4 22.8 18.8 2026 08 08 16 26.14 +22 21.2 2.168 2.555 100.5 23.0 18.9 2026 08 18 16 27.36 +16 22.1 2.272 2.573 95.4 23.1 19.1 2026 08 28 16 30.92 +10 46.8 2.397 2.595 89.6 22.9 19.2 2026 09 07 16 36.41 +05 40.4 2.540 2.620 83.3 22.5 19.4 2026 09 17 16 43.52 +01 04.3 2.696 2.649 76.6 21.7 19.5 2026 09 27 16 51.97 -03 02.3 2.859 2.682 69.7 20.5 19.7 2026 10 07 17 01.53 -06 41.4 3.027 2.717 62.7 19.1 19.9 2026 10 17 17 12.04 -09 55.7 3.193 2.756 55.6 17.4 20.0 2026 10 27 17 23.32 -12 47.9 3.355 2.798 48.5 15.4 20.2 2026 11 06 17 35.24 -15 20.7 3.509 2.842 41.4 13.3 20.4 2026 11 16 17 47.69 -17 36.6 3.653 2.889 34.2 11.1 20.5 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2026 CBAT 2026 May 26 (CBET 5694) Daniel W. E. Green