Electronic Telegram No. 5335 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/2023 V7 = P/2004 DO_29 (SPACEWATCH-LINEAR) On 2023 Nov. 25, R. Weryk (Department of Physics and Astronomy, University of Western Ontario) reported that he identified an apparent new comet discovery in images obtained with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala as being an accidental recovery of comet P/2004 DO_29 (cf. IAUC 8305), adding that four 45-s w-band survey images taken in 1".6 seeing showed a condensed coma of size 2".0 (full-width-at-half-maximum) with a straight tail > 6" long in p.a. 260 degrees. Weryk's recovery observations are tabulated below. Observations of this comet (mag 20.5-20.8) were also identified in images obtained on 2023 Nov. 11.6 UT with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala. M. Rudenko reports on MPEC 2024-B93 that M. Micheli reported a recovery of comet P/2004 DO_29 independently from images taken on 2023 Nov. 11 UT with a 1-m f/4.4 reflector at the European Space Agency's Optical Ground Station at Tenerife (magnitude 20.0-20.8), adding that F. Ocana also reported an independent recovery from images taken 2023 Nov. 13 with the Calar Alto Schmidt telescope (mag 19.8-20.3); no mention was made of any comments regarding physical appearance. The November recovery observations that are described above are tabulated below. 2023 UT R.A. (2000) Decl. Mag. Nov. 11.24408 11 28 44.46 + 6 17 35.5 20.8 11.24860 11 28 44.66 + 6 17 34.2 20.0 11.26253 11 28 45.42 + 6 17 31.6 20.1 13.22242 11 30 31.32 + 6 10 59.2 19.8 13.22710 11 30 31.58 + 6 10 58.5 20.3 25.63440 11 41 06.88 + 5 34 46.2 20.6 25.63832 11 41 07.04 + 5 34 45.8 21.5 25.64226 11 41 07.25 + 5 34 45.2 20.9 As those outside the Minor Planet Center were unaware of recoveries of this comet except for the single night by Weryk (circulated privately to a few by Weryk), M. Jaeger of Vienna reported his independent recovery of this comet at mag 20 in seventeen 100-s exposures taken on 2024 Jan. 17 by Jaeger, E. Prosperi, and S. Prosperi with a 0.3-m f/4 reflector at Oed, Martinsberg, Austria (astrometry tabulated below). 2024 UT R.A. (2000) Decl. Mag. Observer Jan. 17.13525 12 09 50.15 + 5 22 25.2 20.1 Jaeger 17.14080 12 09 50.20 + 5 22 25.9 20.4 " 17.14875 12 09 50.30 + 5 22 27.2 19.7 " Hearing of Jaeger's report through online comet forums, H. Sato (Bunkyo-ku, Tokyo, Japan) writes that CCD images obtained remotely on 2024 Jan. 19.71 UT with a 0.51-m f/6.8 astrograph located at Siding Spring, NSW, Australia, show a strongly condensed coma 10" in diameter with a straight tail 40" long toward p.a. 270 degrees; the magnitude was 19.3 as measured within a circular aperture of radius 6".5. The residuals for the recovery observations are +10'.8 in R.A. and -1'.9 in Decl. from the prediction in NK 1269 by T. Kobayashi (also given for epoch 2024 in the ICQ's 2023 Comet Handbook), with a corresponding correction of Delta(T) = -1.50 days. The following linked orbital elements by S. Nakano (Central Bureau) are from 103 observations spanning 2004 Apr. 11-2024 Jan. 19 (mean residual 0".6). There are no close approaches to major planets. Epoch = 2004 Oct. 2.0 TT T = 2004 Oct. 9.28443 TT Peri. = 41.58759 e = 0.4495120 Node = 147.77741 2000.0 q = 4.0968279 AU Incl. = 14.49558 a = 7.4421753 AU n = 0.04854609 P = 20.30 years Epoch = 2024 June 19.0 TT T = 2024 June 1.61319 TT Peri. = 40.39478 e = 0.4421841 Node = 147.37517 2000.0 q = 4.0774766 AU Incl. = 14.52525 a = 7.3097170 AU n = 0.04987159 P = 19.76 years Epoch = 2044 Apr. 15.0 TT T = 2044 Apr. 16.82113 TT Peri. = 40.94256 e = 0.4427919 Node = 147.36991 2000.0 q = 4.0719770 AU Incl. = 14.52033 a = 7.3078207 AU n = 0.04989100 P = 19.76 years The comet's brightness is running about a magnitude fainter than in 2004- 2005. The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 10.5 and 2.5n = 10 for the magnitudes. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2023 12 02 11 46.10 +05 20.1 4.359 4.205 74.5 13.1 19.9 2023 12 12 11 53.25 +05 03.4 4.198 4.192 82.9 13.5 19.8 2023 12 22 11 59.40 +04 55.4 4.034 4.179 91.6 13.6 19.7 2024 01 01 12 04.43 +04 57.2 3.872 4.167 100.6 13.4 19.6 2024 01 11 12 08.20 +05 09.5 3.716 4.156 110.0 12.8 19.5 2024 01 21 12 10.59 +05 32.8 3.569 4.146 119.7 11.9 19.4 2024 01 31 12 11.54 +06 06.8 3.436 4.136 129.7 10.6 19.3 2024 02 10 12 11.04 +06 50.8 3.322 4.127 140.0 8.8 19.3 2024 02 20 12 09.16 +07 42.9 3.229 4.119 150.5 6.8 19.2 2024 03 01 12 06.13 +08 40.0 3.163 4.111 160.7 4.6 19.1 2024 03 11 12 02.25 +09 38.6 3.124 4.104 169.1 2.6 19.1 2024 03 21 11 57.93 +10 34.7 3.116 4.098 169.2 2.6 19.1 2024 03 31 11 53.65 +11 24.3 3.136 4.093 160.9 4.6 19.1 2024 04 10 11 49.84 +12 04.3 3.184 4.088 150.9 6.8 19.1 2024 04 20 11 46.92 +12 32.7 3.257 4.085 140.8 9.0 19.2 2024 04 30 11 45.16 +12 48.4 3.351 4.082 130.8 10.8 19.2 2024 05 10 11 44.73 +12 51.6 3.463 4.079 121.3 12.2 19.3 2024 05 20 11 45.72 +12 42.8 3.588 4.078 112.1 13.3 19.4 2024 05 30 11 48.10 +12 23.2 3.723 4.078 103.3 14.0 19.5 2024 06 09 11 51.80 +11 54.0 3.863 4.078 94.9 14.4 19.5 2024 06 19 11 56.71 +11 16.5 4.006 4.079 86.9 14.4 19.6 2024 06 29 12 02.72 +10 32.1 4.148 4.080 79.1 14.2 19.7 2024 07 09 12 09.69 +09 41.8 4.287 4.083 71.7 13.7 19.8 2024 07 19 12 17.52 +08 46.8 4.421 4.086 64.4 13.0 19.8 2024 07 29 12 26.07 +07 48.1 4.548 4.090 57.4 12.1 19.9 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2024 CBAT 2024 January 23 (CBET 5335) Daniel W. E. Green