Electronic Telegram No. 5241 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/2010 VH_95 (CATALINA) [Editor's note: this text replaces that on CBET 5240 (additional information)] P. Veres, Minor Planet Center, reports that he has found cometary activity in images of the minor planet 2010 VH_95 (cf. MPEC 2010-X41; MPC 72532) in archival CCD images taken with 0.5-m f/2 Schmidt reflectors in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program. Veres first identified a straight 15" tail in p.a. 282 degrees in ATLAS images taken at Rio Hurtado, Chile, on 2023 Mar. 14 (magnitude given as 16.3-17.6), and then found a 12" tail in ATLAS images taken on 2023 Jan. 16 and 24 (at p.a. 70 and 75 deg, respectively, with magnitudes of 18.0 and 17.7) at Haleakala, Hawaii, tails of 12"-14" length in p.a. 75-78 deg in ATLAS images taken on 2023 Feb. 28 (mag 17.5-17.7), Mar. 9 (mag 16.9-17.9), and Mar. 12 (mag 17.1-17.7) at Sutherland, South Africa, and a 12" tail in p.a. 78 deg in ATLAS images taken on 2023 Mar. 18 at Haleakala (magnitude 16.7-17.7). This object was discovered as an apparently asteroidal object on CCD images obtained with the Catalina Sky Survey's 0.68-m Schmidt reflector in Nov. 2010 (the discovery observations from MPS 355738 are tabulated below). H. Sato then reported a stellar appearance at mag 19.2 on CCD images obtained remotedly with a 0.50-m f/6.8 reflector at Mayhill, NM, USA, on 2010 Nov. 17. 2010 UT R.A. (2000) Decl. Mag. Nov. 7.48513 8 13 06.67 +22 54 29.0 19.2 7.49205 8 13 07.46 +22 54 21.9 19.4 7.49902 8 13 08.25 +22 54 15.0 19.2 7.50595 8 13 08.94 +22 54 07.6 19.4 10.38862 8 18 34.77 +22 03 51.8 19.6 10.39509 8 18 35.46 +22 03 45.3 19.2 10.40152 8 18 36.14 +22 03 38.6 19.2 10.40794 8 18 36.86 +22 03 31.7 19.3 Pre-discovery single-night observations were identified after the discovery announcement of 2010 VH_95 from images obtained at Haleakala on 1997 Dec. 28 (at red mag 19.5) and on 1998 Jan. 26 (red mag 19.6), as well as with the Spacewatch telescope at Kitt Peak on 2010 Oct. 8 (mag 20.0). Additional astrometry appears on MPEC 2023-F167. The following updated orbital elements by S. Nakano (Central Bureau) are from 926 observations spanning 1997-2023 (mean residual 0".5). The comet passed 0.101 AU from Jupiter on 1937 Jan. 13, 0.90 AU from Jupiter on 2008 Aug. 31, and 0.24 AU from Jupiter on 2020 Feb. 25 UT; it will also pass 0.37 AU from Jupiter on 2032 Apr. 3. Epoch = 1985 May 15.0 TT T = 1985 May 5.60022 TT Peri. = 185.89853 e = 0.4844282 Node = 274.69698 2000.0 q = 1.7877159 AU Incl. = 13.82632 a = 3.4674434 AU n = 0.15264761 P = 6.46 years Epoch = 1991 Oct. 31.0 TT T = 1991 Oct. 17.83116 TT Peri. = 186.00892 e = 0.4860936 Node = 274.65817 2000.0 q = 1.7783254 AU Incl. = 13.84661 a = 3.4604073 AU n = 0.15311342 P = 6.44 years Epoch = 1998 Mar. 8.0 TT T = 1998 Mar. 17.11129 TT Peri. = 186.02626 e = 0.4897339 Node = 274.54876 2000.0 q = 1.7590379 AU Incl. = 13.87306 a = 3.4472950 AU n = 0.15398783 P = 6.40 years Epoch = 2004 Aug. 23.0 TT T = 2004 Aug. 11.56203 TT Peri. = 186.18458 e = 0.4905687 Node = 274.48917 2000.0 q = 1.7546140 AU Incl. = 13.88222 a = 3.4442604 AU n = 0.15419138 P = 6.39 years Epoch = 2010 Nov. 20.0 TT T = 2010 Dec. 7.40013 TT Peri. = 189.35822 e = 0.5187990 Node = 272.48471 2000.0 q = 1.6114398 AU Incl. = 13.56209 a = 3.3487875 AU n = 0.16083208 P = 6.13 years Epoch = 2017 Jan. 7.0 TT T = 2017 Jan. 25.98656 TT Peri. = 189.51405 e = 0.5189852 Node = 272.42272 2000.0 q = 1.6111068 AU Incl. = 13.56249 a = 3.3493915 AU n = 0.16078858 P = 6.13 years Epoch = 2023 Feb. 25.0 TT T = 2023 Feb. 21.37982 TT Peri. = 205.17729 e = 0.5775343 Node = 257.00052 2000.0 q = 1.3681597 AU Incl. = 7.17207 a = 3.2385112 AU n = 0.16911650 P = 5.83 years Epoch = 2028 Dec. 15.0 TT T = 2028 Dec. 23.11138 TT Peri. = 205.31765 e = 0.5773777 Node = 256.93005 2000.0 q = 1.3691121 AU Incl. = 7.16842 a = 3.2395641 AU n = 0.16903406 P = 5.83 years Epoch = 2034 Oct. 5.0 TT T = 2034 Oct. 6.24468 TT Peri. = 250.41171 e = 0.6064630 Node = 211.84820 2000.0 q = 1.2432166 AU Incl. = 4.15065 a = 3.1590849 AU n = 0.17553436 P = 5.62 years Epoch = 2040 May 6.0 TT T = 2040 May 20.66771 TT Peri. = 250.59254 e = 0.6065149 Node = 211.73721 2000.0 q = 1.2430677 AU Incl. = 4.15010 a = 3.1591228 AU n = 0.17553119 P = 5.62 years Epoch = 2045 Dec. 6.0 TT T = 2045 Dec. 20.28550 TT Peri. = 254.21693 e = 0.6187058 Node = 208.60828 2000.0 q = 1.1879662 AU Incl. = 4.16773 a = 3.1156155 AU n = 0.17922075 P = 5.50 years The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 16.0 and 2.5n = 8 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2023 02 25 03 50.26 +15 42.8 1.073 1.369 83.0 45.9 17.2 2023 03 07 04 23.86 +16 24.0 1.120 1.377 81.1 45.4 17.4 2023 03 17 04 58.48 +16 49.8 1.174 1.393 79.5 44.6 17.5 2023 03 27 05 33.53 +16 56.9 1.237 1.418 78.0 43.5 17.7 2023 04 06 06 08.40 +16 43.2 1.310 1.451 76.5 42.1 17.9 2023 04 16 06 42.54 +16 08.7 1.393 1.490 75.0 40.5 18.1 2023 04 26 07 15.57 +15 14.9 1.486 1.536 73.3 38.8 18.4 2023 05 06 07 47.20 +14 04.3 1.589 1.587 71.4 37.0 18.6 2023 05 16 08 17.27 +12 39.8 1.701 1.641 69.2 35.2 18.9 2023 05 26 08 45.77 +11 04.3 1.821 1.700 66.8 33.2 19.1 2023 06 05 09 12.72 +09 20.6 1.948 1.761 64.1 31.2 19.4 2023 06 15 09 38.21 +07 31.1 2.082 1.824 61.2 29.2 19.7 2023 06 25 10 02.39 +05 37.8 2.220 1.889 58.0 27.1 19.9 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2023 CBAT 2023 March 28 (CBET 5241) Daniel W. E. Green