Electronic Telegram No. 5315 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/2023 V4 (CAMARASA-DUSZANOWICZ) Jordi Camarasa (Sabadell, Barcelona, Spain) reports the discovery of a somewhat-diffuse comet by Grzegorz Duszanowicz (Akersberga, Sweden) and himself on CMOS-camera images taken on Nov. 5.1 UT using two 0.28-m f/1.9 Schmidt-Cassegrain (Celestron C11) telescopes located at Duszanowicz's "Moonbase South Observatory" at the Hakos "Astro Farm" in Namibia (discovery observations tabulated below). Follow-up observations by Camarasa and Duszanowicz with a Celestron 14 f/7 telescope on Nov. 5.81-5.86 revealed a clear tail, and the cometary nature of the object was obvious. 2023 UT R.A. (2000) Decl. Mag. Observer Nov. 5.05544 3 54 14.20 -48 50 30.8 18.7 Camarasa 5.06154 3 54 13.59 -48 50 30.9 18.5 " 5.06612 3 54 13.04 -48 50 31.1 18.6 " 5.06765 3 54 12.88 -48 50 31.4 18.6 " After the comet was posted to the Minor Planet Center's PCCP webpage, CCD astrometrists elsewhere confirmed the cometary appearance. Eight stacked 60-s exposures taken remotely on Nov. 6.2 UT by H. Sato (Bunkyo-ku, Tokyo, Japan) using a "Deep Sky Chile" 0.51-m f/6.8 astrograph located at Rio Hurtado, Childe, show a strongly condensed coma 8" in diameter with a 10" tail toward p.a. 340 degrees; the magnitude was 18.8 as measured within a circular aperture of radius 4".3. T. Prystavski (Lviv, Ukraine) writes that images taken remotely also with a "Deep Sky Chile" 0.51-m f/6.8 reflector at Rio Hurtado on Nov. 7.1 show this to be definitely a comet; the condensed coma has a dize of 7".1 and total magnitude 19.3, with a slightly curved tail 0'.3 long. The available astrometry appears on MPEC 2023-V192. The following preliminary parabolic orbital elements by S. Nakano (Central Bureau) are from 67 observations spanning Nov. 5-9 (mean residual 0".5). T = 2024 May 29.7019 TT Peri. = 50.7348 Node = 66.5886 2000.0 q = 1.121179 AU Incl. = 66.9310 The following ephemeris by the undersigned from the above orbital elements uses photometric power-law parameters H = 12.5 and 2.5n = 8 for the magnitudes. The comet will be on the far side of the sun at perihelion next year. Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag. 2023 10 23 04 15.05 -47 55.3 2.737 3.251 112.5 16.4 18.8 2023 11 02 03 59.66 -48 43.0 2.611 3.142 113.5 16.8 18.6 2023 11 12 03 40.93 -48 52.2 2.501 3.031 113.2 17.5 18.3 2023 11 22 03 20.23 -48 11.2 2.408 2.920 111.6 18.3 18.1 2023 12 02 02 59.48 -46 33.1 2.333 2.808 108.6 19.4 17.9 2023 12 12 02 40.59 -43 57.5 2.275 2.695 104.4 20.7 17.7 2023 12 22 02 24.99 -40 30.0 2.235 2.581 99.2 22.1 17.5 2024 01 01 02 13.37 -36 20.7 2.210 2.467 93.1 23.5 17.4 2024 01 11 02 05.78 -31 40.5 2.197 2.352 86.5 24.7 17.2 2024 01 21 02 01.92 -26 39.5 2.195 2.238 79.6 25.6 17.0 2024 01 31 02 01.32 -21 25.9 2.200 2.123 72.5 26.3 16.8 2024 02 10 02 03.51 -16 05.2 2.209 2.008 65.3 26.5 16.6 2024 02 20 02 08.09 -10 41.0 2.218 1.895 58.3 26.3 16.5 2024 03 01 02 14.74 -05 14.8 2.225 1.783 51.3 25.7 16.2 2024 03 11 02 23.23 +00 13.2 2.228 1.673 44.6 24.6 16.0 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2023 CBAT 2023 November 11 (CBET 5315) Daniel W. E. Green