[Iaude] CBET 5313: COMET C/2023 V3

[quai at eps.harvard.edu]

                                                  Electronic Telegram No. 5313
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau at eps.harvard.edu (alternate cbat at iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2023 V3 (PANSTARRS)
     R. Weryk, Department of Physics and Astronomy, University of Western
Ontario, reports the discovery of another comet in images obtained on Nov. 3
with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala (discovery
observations tabulated below).  Four 45-s w-band survey images taken in 1".3
seeing show a diffuse coma of size around 1".8 (full-width-at-half-maximum)
with a possible straight 4" tail in p.a. 280 degrees.

     2023 UT             R.A. (2000) Decl.       Mag.
     Nov.  3.45563    3 32 09.03   -23 17 52.6   20.5
           3.46816    3 32 08.56   -23 17 51.9   21.3
           3.48070    3 32 08.12   -23 17 50.9   20.7
           3.49323    3 32 07.65   -23 17 49.4   21.0
           3.55205    3 32 05.53   -23 17 44.9   21.9
           3.55287    3 32 05.46   -23 17 44.9   21.2

Pre-discovery Pan-STARRS1 observations were identified in the Minor Planet
Center's "isolated tracklet file" from Oct. 11.5 UT (mag 21.3-21.8).  Also,
additional Pan-STARRS1 observations were subsequently reported from Sept. 25.5
(mag 20.5-21.7), Oct. 7.54-7.57 (mag 20.7-21.5), and Oct. 30.5 (mag 21.0-21.9)
-- as were observations made with the Pan-STARRS2 1.8-m Ritchey-Chretien
reflector at Haleakala on Oct. 15.5 (mag 20.9-21.1).
     After the comet was posted on the MPC's PCCP webpage, other CCD
astrometrists have commented on the comet's appearance.  Exposures obtained by
M. T. Read with the Spacewatch 1.8-m f/2.7 reflector at Kitt Peak on Nov.
5.34-5.35 UT show a "slight" coma and a tail about 10" long toward p.a. 270
degrees.  Ten stacked 120-s exposures taken remotely by H. Sato (Bunkyo-ku,
Tokyo, Japan) with a "Deep Sky Chile" 0.51-m f/6.8 astrograph at Rio Hurtado,
Chile, on Nov. 6.2 show a strongly condensed coma 4" in diameter with a
fan-like tail 10" long spanning p.a. 265-315 degrees; the magnitude was 20.9
as measured within a circular aperture of radius 2".2.
     The available astrometry appears on MPEC 2023-V109.  The following
elliptical orbital elements by S. Nakano (Central Bureau) are from 34
observations spanning 2023 Sept. 25-Nov. 6 (mean residual 0".3).  These
indicate that the comet will pass 0.84 AU from Jupiter on 2025 Feb. 23 UT.

     T = 2023 Aug.  6.21148 TT        Peri. = 291.51351
     e = 0.6624167                    Node  =  91.50178 2000.0
     q = 4.4705627 AU                 Incl. =  40.25114
       a = 13.2428450 AU   n = 0.02045183   P =  48.19 years

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.

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase  Mag.
2023 10 23    03 38.54   -23 22.5    3.729    4.500   136.1     8.8  20.6
2023 11 02    03 33.01   -23 19.6    3.714    4.508   138.8     8.3  20.6
2023 11 12    03 26.93   -22 59.7    3.721    4.517   139.2     8.2  20.6
2023 11 22    03 20.79   -22 21.4    3.752    4.527   137.2     8.5  20.6
2023 12 02    03 15.07   -21 25.1    3.807    4.538   133.0     9.1  20.7
2023 12 12    03 10.18   -20 12.3    3.885    4.550   127.3     9.9  20.7
2023 12 22    03 06.46   -18 45.7    3.982    4.562   120.6    10.7  20.8
2024 01 01    03 04.10   -17 08.4    4.098    4.576   113.2    11.4  20.8
2024 01 11    03 03.18   -15 23.6    4.228    4.590   105.6    11.9  20.9
2024 01 21    03 03.71   -13 34.3    4.369    4.605    97.7    12.2  21.0
2024 01 31    03 05.63   -11 43.1    4.517    4.622    89.9    12.3  21.1
2024 02 10    03 08.83   -09 52.1    4.669    4.639    82.2    12.2  21.2
2024 02 20    03 13.18   -08 02.9    4.822    4.656    74.5    11.8  21.3


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2023 CBAT
2023 November 8                  (CBET 5313)              Daniel W. E. Green