[Iaude] CBET 5311: COMET C/2023 V1

quai at eps.harvard.edu quai at eps.harvard.edu
Sat Nov 4 12:32:35 EDT 2023


                                                  Electronic Telegram No. 5311
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 V1 (LEMMON)
     A comet has been discovered at Mt. Lemmon using the 1.5-m reflector
(observer J. B. Fazekas) and the 1.0-m Steward Observatory reflector (observer
R. A. Kowalski, with Kowalski's observations reported first to the Minor
Planet Center); the discovery observations are tabulated below.  Fazekas
reported that four 30-s exposures show an obvious comet with an 8" coma and
no obvious tail; Kowalski reported a diffuse 20" coma with no tail.

     2023 UT             R.A. (2000) Decl.       Mag.   Observer
     Nov.  2.16917   22 20 27.15   +40 06 58.0   20.5   Fazekas
           2.17433   22 20 26.99   +40 06 56.2   21.0     "
           2.17950   22 20 26.85   +40 06 54.7   20.9     "
           2.18466   22 20 26.65   +40 06 53.6   20.9     "
           2.23372   22 20 24.75   +40 06 38.8   20.3   Kowalski
           2.24051   22 20 24.46   +40 06 36.3   20.8     "
           2.24710   22 20 24.26   +40 06 34.7   21.3     "
           2.25357   22 20 23.98   +40 06 33.3   20.3     "

P. Veres, MPC, relates that he started with the above observations and
searched the MPC's "isolated tracklet file" (ITF) for possible pre-discovery
observations, which resulted in his finding Mt. Lemmon Survey images of this
comet on separate nights (previously unlinked) from Sept. 9 (mag 21.1-21.5),
Sept. 21 (mag 20.9-21.9), Oct. 4 (mag 20.2-21.0), and Oct. 21 (mag 20.7-21.2).
Veres also found Oct. 22 images (mag 21.1-21.2) in the ITF that were taken
with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala.  Veres
then noticed a nearly parabolic orbit for these observations and posted it
to the MPC's PCCP webpage.
     After the comet was posted to the PCCP webpage, R. Weryk (Department of
Physics and Astronomy, University of Western Ontario) writes that he
identified pre-discovery images of this comet in Pan-STARRS1 1.8-m reflector
observations from Aug. 2 UT (mag 21.5-22.7), Aug. 23 (mag 21.4-21.8), and
Sept. 29 (mag 21.6), as well as on Oct. 27 (Pan-STARRS2 1.8-m reflector; mag
20.4).  He adds that four 45-s stacked w-band survey Pan-STARRS1 images taken
on Oct. 22.25-22.32 UT (which had been in the ITF) show a diffuse coma of
size 1".6 (full-width-at-half-maximum) in 1".4 seeing with no obvious tail.
     The available astrometry appears on MPEC 2023-V23.  The following
orbital elements by S. Nakano (Central Bureau) are from 41 observations
spanning 2023 Aug. 2-Nov. 2 (mean residual 0".3), with corresponding
"original" and "future" values of 1/a being +0.000644 and +0.000768 (+/-
0.000022) AU**-1, respectively.

                    Epoch = 2025 July 24.0 TT
     T = 2025 July 13.06633 TT        Peri. = 103.32185
     e = 1.0004488                    Node  =  15.04281 2000.0
     q = 5.0921812 AU                 Incl. = 102.01295

The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 10.0 and 2.5n = 8 for the
magnitudes.

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase  Mag.
2023 10 23    22 27.61   +40 54.7    6.252    6.898   127.0     6.6  20.7
2023 11 02    22 20.56   +40 07.8    6.286    6.851   121.0     7.1  20.7
2023 11 12    22 14.96   +39 18.5    6.339    6.804   114.1     7.6  20.7
2023 11 22    22 10.84   +38 30.2    6.407    6.757   106.7     8.0  20.7
2023 12 02    22 08.15   +37 46.0    6.484    6.711    99.1     8.3  20.7
2023 12 12    22 06.81   +37 08.2    6.567    6.665    91.4     8.5  20.7
2023 12 22    22 06.66   +36 38.7    6.651    6.619    83.9     8.5  20.7
2024 01 01    22 07.57   +36 18.8    6.731    6.574    76.6     8.4  20.7
2024 01 11    22 09.35   +36 09.4    6.804    6.529    69.7     8.1  20.7
2024 01 21    22 11.87   +36 11.0    6.866    6.485    63.4     7.8  20.7
2024 01 31    22 14.95   +36 23.7    6.915    6.441    57.6     7.4  20.7
2024 02 10    22 18.44   +36 47.4    6.947    6.397    52.7     7.0  20.7
2024 02 20    22 22.21   +37 22.1    6.962    6.354    48.7     6.7  20.6
2024 03 01    22 26.09   +38 07.4    6.959    6.311    46.0     6.5  20.6
2024 03 11    22 29.97   +39 03.0    6.937    6.269    44.7     6.4  20.6
2024 03 21    22 33.68   +40 08.5    6.896    6.227    44.7     6.5  20.5
2024 03 31    22 37.08   +41 23.4    6.837    6.186    46.1     6.7  20.5
2024 04 10    22 40.01   +42 47.1    6.761    6.145    48.6     7.0  20.5
2024 04 20    22 42.29   +44 19.1    6.669    6.104    52.1     7.5  20.4
2024 04 30    22 43.71   +45 58.7    6.565    6.065    56.3     7.9  20.3
2024 05 10    22 44.05   +47 44.8    6.449    6.025    61.0     8.4  20.3
2024 05 20    22 43.01   +49 36.2    6.325    5.987    66.1     8.9  20.2
2024 05 30    22 40.29   +51 31.2    6.196    5.949    71.3     9.3  20.2
2024 06 09    22 35.52   +53 27.6    6.064    5.911    76.6     9.6  20.1
2024 06 19    22 28.30   +55 22.4    5.933    5.874    81.8     9.9  20.0
2024 06 29    22 18.23   +57 11.6    5.806    5.838    86.8    10.0  19.9
2024 07 09    22 04.99   +58 50.4    5.687    5.802    91.4    10.1  19.9
2024 07 19    21 48.47   +60 13.1    5.578    5.767    95.7    10.1  19.8
2024 07 29    21 28.94   +61 13.6    5.481    5.733    99.2    10.1  19.8
2024 08 08    21 07.16   +61 46.7    5.400    5.699   102.1    10.0  19.7
2024 08 18    20 44.42   +61 48.9    5.336    5.666   104.0    10.0  19.7
2024 08 28    20 22.25   +61 19.9    5.290    5.634   104.9    10.0  19.6
2024 09 07    20 02.06   +60 22.4    5.261    5.603   104.7    10.0  19.6
2024 09 17    19 44.84   +59 02.0    5.250    5.572   103.6    10.1  19.6
2024 09 27    19 31.02   +57 25.7    5.255    5.542   101.5    10.2  19.6
2024 10 07    19 20.59   +55 40.4    5.273    5.513    98.7    10.3  19.5
2024 10 17    19 13.29   +53 52.7    5.303    5.485    95.3    10.4  19.5
2024 10 27    19 08.69   +52 08.0    5.340    5.458    91.5    10.5  19.5
2024 11 06    19 06.37   +50 30.6    5.383    5.431    87.5    10.5  19.5
2024 11 16    19 05.92   +49 03.9    5.427    5.405    83.5    10.5  19.5
2024 11 26    19 06.95   +47 50.2    5.470    5.381    79.6    10.4  19.5


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

                         (C) Copyright 2023 CBAT
2023 November 4                  (CBET 5311)              Daniel W. E. Green



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