[Iaude] CBET 5362: COMET C/2019 O2

quai at eps.harvard.edu quai at eps.harvard.edu
Fri Mar 1 21:36:59 EST 2024


                                                  Electronic Telegram No. 5362
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/2019 O2 (PANSTARRS)
     An apparently asteroidal object discovered images obtained on 2019 July
24 (discovery observations tabulated below) with the Pan-STARRS1 1.8-m
Ritchey-Chretien reflector at Haleakala has been found to show cometary
activity as reported by observers elsewhere.  The object was designated
A/2019 O2 when announced on MPEC 2019-P54 due to its nearly parabolic orbit.

     2019 UT             R.A. (2000) Decl.       Mag.
     July 24.52254   20 20 35.84   +75 40 48.0   20.5
          24.53640   20 20 34.31   +75 40 47.9   20.7
          24.55022   20 20 32.86   +75 40 47.7   20.8
          24.56407   20 20 31.40   +75 40 47.3   20.6

R. Weryk, Department of Physics and Astronomy, University of Western Ontario,
writes that he searched for the comet in Pan-STARRS exposures, finding
apparently stellar pre-discovery Pan-STARRS1 images of the comet as far back
as 2014 Dec. 8 (at mag 21.7-22.3) and 20 (mag 22.5-22.9), as well as on 2016
Sept. 19 (mag 21.9-22.3) and Nov. 7 (mag 20.9-22.4).  Weryk identified post-
discovery observations that all show the comet as stellar in appearance.  A
single observation of the comet with a stellar appearance that was made with
the 3.6-m Canada-France-Hawaii Telescope on 2011 Nov. 28 was measured and
reported by S. Deen (Simi Valley, CA, USA) in 2022 at magnitude r = 22.6.
The astrometry for these observations appear on MPEC 2024-E7.
     K. Wierzchos, Lunar and Planetary Laboratory, University of Arizona,
writes that four unfiltered 30-s exposures taken on 2023 June 30.3 UT with
the Mt. Lemmon 1.5-m reflector show a short, broad tail of length 6"
spanning p.a. 190-270 degrees with a very condensed coma of size 3" and
magnitude 19.8-19.9.
     The following orbital elements by S. Nakano (Central Bureau) are from 392
observations spanning 2011 Nov. 28-2023 Sept. 12 (mean residual 0".3), with
corresponding "original" and "future" values of 1/a (with respect to the
solar-system barycenter) being +0.017236 and +0.017271 (+/- 0.000001) AU**-1,
respectively.  The orbital period is around 440 years.

                    Epoch = 2023 Apr.  6.0 TT
     T = 2023 Apr.  7.22843 TT        Peri. = 129.63980
     e = 0.8327256                    Node  =  48.26287 2000.0
     q = 9.6827741 AU                 Incl. =  93.30726

The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 6.5 and 2.5n = 8 for the magnitudes.

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase  Mag.
2024 01 11    16 10.28   +15 48.5   10.222    9.784    61.1     5.0  19.5
2024 01 21    16 12.23   +15 46.9   10.112    9.792    68.4     5.4  19.5
2024 01 31    16 13.64   +15 50.0    9.990    9.799    76.0     5.6  19.4
2024 02 10    16 14.43   +15 57.3    9.861    9.807    84.0     5.7  19.4
2024 02 20    16 14.54   +16 07.9    9.729    9.815    92.1     5.8  19.4
2024 03 01    16 13.92   +16 20.9    9.598    9.824   100.3     5.7  19.3
2024 03 11    16 12.53   +16 35.1    9.472    9.832   108.5     5.5  19.3
2024 03 21    16 10.38   +16 49.4    9.356    9.841   116.5     5.2  19.3
2024 03 31    16 07.50   +17 02.3    9.254    9.850   124.2     4.8  19.3
2024 04 10    16 03.94   +17 12.6    9.170    9.860   131.3     4.4  19.3
2024 04 20    15 59.80   +17 18.9    9.108    9.869   137.3     4.0  19.3
2024 04 30    15 55.21   +17 20.0    9.070    9.879   141.6     3.6  19.2
2024 05 10    15 50.33   +17 15.2    9.058    9.889   143.6     3.5  19.2
2024 05 20    15 45.32   +17 03.6    9.073    9.900   143.0     3.5  19.3
2024 05 30    15 40.36   +16 45.1    9.115    9.910   139.8     3.8  19.3
2024 06 09    15 35.62   +16 19.8    9.182    9.921   134.6     4.2  19.3
2024 06 19    15 31.26   +15 48.1    9.274    9.932   128.0     4.6  19.3
2024 06 29    15 27.40   +15 10.6    9.386    9.943   120.7     5.0  19.3
2024 07 09    15 24.12   +14 28.3    9.516    9.955   112.8     5.4  19.4
2024 07 19    15 21.51   +13 41.9    9.660    9.967   104.7     5.7  19.4
2024 07 29    15 19.58   +12 52.7    9.814    9.978    96.4     5.8  19.5
2024 08 08    15 18.35   +12 01.4    9.973    9.991    88.1     5.8  19.5
2024 08 18    15 17.81   +11 09.1   10.133   10.003    79.8     5.7  19.5
2024 08 28    15 17.91   +10 16.4   10.290   10.016    71.5     5.5  19.6
2024 09 07    15 18.61   +09 24.3   10.441   10.029    63.3     5.2  19.6


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

                         (C) Copyright 2024 CBAT
2024 March 2                     (CBET 5362)              Daniel W. E. Green




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