Electronic Telegram No. 5710 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/2026 M2 = P/2018 VN_2 = P/2010 W10 (LEONARD) J.-F. Soulier (Maisoncelles, France) reports his apparent recovery of this comet (cf. CBET 4573) on CCD images obtained with a 0.25-m f/3.5 reflector on June 22 (astrometry tabulated below), without commenting on the object's appearance. Confirming observations have been sent to the Central Bureau (and to the Minor Planet Center, as posted at their "Recovery Page Criteria" webpage), including the astrometry below from M. Masek (Institute of Physics of the Czech Academy of Sciences), whose unfiltered CCD images (obtained with a 25-cm Schmidt-Cassegrain reflector located at the site of the future Cherenkov Telescope Array at La Palma, Canary Islands) show a condensed coma of diameter 0'.2 and a tail 0'.2 long in p.a. 257 degrees. 2026 UT R.A. (2000) Decl. Mag. Observer June 22.04211 0 25 11.87 +20 18 35.3 19.0 Soulier 22.06886 0 25 14.56 +20 18 54.1 18.9 " 22.09561 0 25 17.34 +20 19 13.3 19.1 " 24.12229 0 28 44.13 +20 42 55.7 18.6 Masek 24.14341 0 28 46.29 +20 43 11.1 18.5 " H. Sato (Bunkyo-ku, Tokyo, Japan) writes that CCD images obtained remotely with a 0.51-m f/6.8 astrograph located at Siding Spring, NSW, Australia, show a strongly condensed with a coma 10" in diameter with a tail 15" long in p.a. 260 degrees; the magnitude was 19.0 as measured within a circular aperture of radius 6".5. R. Weryk, Department of Physics and Astronomy, University of Western Ontario, reports astrometry of newly identified observations of this comet as obtained with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala from 2010 Nov. 27.5 and Dec. 5.5 UT (astrometry tabulated below), as well as from 2017 June 23.4 (mag 23.2-23.9), 2019 Jan. 6.32-6.36 (mag 20.5-21.0), and 2019 Jan. 10.3 (mag 20.8-21.5). The comet was presumably stellar in all images. The 2010 apparition was assigned the designation P/2010 W10 when the recovery was announced on MPEC 2026-M133. The designation P/2026 M2 has been given to the comet for its current apparition, following the use of P/2026 M1 for the recovery of P/2021 N1 (cf. CBET 5707). 2010 UT R.A. (2000) Decl. Mag. Nov. 27.52255 5 50 29.77 + 8 08 10.2 22.1 27.53447 5 50 29.18 + 8 08 05.4 21.6 Dec. 5.45734 5 44 02.91 + 7 15 40.7 21.1 5.47362 5 44 02.05 + 7 15 35.1 21.3 The residuals of the recovery observations are +214" in R.A. and +24" in Decl. from the prediction on NK 4475 (and the ICQ's 2026 Comet Handbook), with a corresponding correction of Delta(T) = -0.17 day. The following linked orbital elements by S. Nakano (Central Bureau) are from 148 observations spanning 2010 Nov. 27-2026 June 24 (mean residual 0".5), with corresponding non-gravitational parameters A1 = +0.50 +/- 0.32, A2 = +0.0373 +/- 0.0034. There were/are no close approaches to major planets in the period 1970-2060. Epoch = 2002 Feb. 15.0 TT T = 2002 Feb. 19.53210 TT Peri. = 138.24334 e = 0.4835692 Node = 227.14448 2000.0 q = 2.0791555 AU Incl. = 18.23119 a = 4.0260099 AU n = 0.12200899 P = 8.08 years Epoch = 2010 Mar. 25.0 TT T = 2010 Apr. 3.85907 TT Peri. = 138.80301 e = 0.4788856 Node = 226.52713 2000.0 q = 2.1148054 AU Incl. = 18.24249 a = 4.0582361 AU n = 0.12055858 P = 8.18 years Epoch = 2018 June 11.0 TT T = 2018 June 5.37915 TT Peri. = 138.77536 e = 0.4775214 Node = 226.54876 2000.0 q = 2.1226219 AU Incl. = 18.24045 a = 4.0626011 AU n = 0.12036433 P = 8.19 years Epoch = 2026 Aug. 28.0 TT T = 2026 Aug. 15.68620 TT Peri. = 138.93238 e = 0.4778879 Node = 226.42618 2000.0 q = 2.1195567 AU Incl. = 18.25554 a = 4.0595818 AU n = 0.12049863 P = 8.18 years Epoch = 2034 Oct. 5.0 TT T = 2034 Oct. 17.93095 TT Peri. = 138.96138 e = 0.4774348 Node = 226.34701 2000.0 q = 2.1244627 AU Incl. = 18.26478 a = 4.0654499 AU n = 0.12023783 P = 8.20 years Epoch = 2042 Dec. 22.0 TT T = 2042 Dec. 16.66832 TT Peri. = 139.22780 e = 0.4796644 Node = 226.23155 2000.0 q = 2.1046742 AU Incl. = 18.35822 a = 4.0448401 AU n = 0.12115798 P = 8.14 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 14.0 and 2.5n = 10 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2026 06 09 00 02.58 +17 38.7 2.302 2.190 70.8 26.0 19.2 2026 06 19 00 19.98 +19 42.4 2.191 2.171 75.4 26.9 19.1 2026 06 29 00 36.93 +21 38.6 2.082 2.155 80.2 27.7 18.9 2026 07 09 00 53.29 +23 25.2 1.973 2.142 85.1 28.2 18.8 2026 07 19 01 08.80 +24 59.8 1.866 2.132 90.4 28.5 18.6 2026 07 29 01 23.18 +26 20.0 1.762 2.124 96.1 28.4 18.5 2026 08 08 01 36.11 +27 23.1 1.660 2.120 102.2 27.9 18.4 2026 08 18 01 47.15 +28 06.1 1.563 2.120 108.9 26.9 18.2 2026 08 28 01 55.91 +28 25.7 1.472 2.122 116.3 25.3 18.1 2026 09 07 02 02.00 +28 18.3 1.389 2.127 124.4 23.0 18.0 2026 09 17 02 05.15 +27 40.3 1.317 2.136 133.4 20.0 17.9 2026 09 27 02 05.37 +26 29.0 1.259 2.147 143.2 16.3 17.8 2026 10 07 02 03.05 +24 44.4 1.220 2.162 153.7 11.8 17.8 2026 10 17 01 58.94 +22 30.7 1.203 2.179 164.4 7.1 17.8 2026 10 27 01 54.20 +19 58.2 1.210 2.199 172.2 3.5 17.8 2026 11 06 01 49.97 +17 20.7 1.244 2.222 167.2 5.7 17.9 2026 11 16 01 47.25 +14 52.9 1.304 2.247 156.7 10.0 18.1 2026 11 26 01 46.68 +12 46.3 1.389 2.274 145.9 14.1 18.3 2026 12 06 01 48.50 +11 07.1 1.494 2.304 135.7 17.4 18.5 2026 12 16 01 52.67 +09 56.5 1.617 2.336 126.0 19.9 18.7 2026 12 26 01 59.03 +09 12.6 1.754 2.369 117.0 21.7 19.0 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2026 CBAT 2026 June 30 (CBET 5710) Daniel W. E. Green