[Iaude] CBET 5356: COMET P/2024 C5 = P/2012 WA_34

[quai at eps.harvard.edu]

                                                  Electronic Telegram No. 5356
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 P/2024 C5 = P/2012 WA_34 (LEMMON-PANSTARRS)
     E. Schwab, Egelsbach, Germany, reports the recovery of comet P/2012 WA_34
(cf. CBET 3379) on ten 600-s CCD exposures taken on Feb. 13.0 UT through a
collaboration with F. Ocana, D. Abreu, M. Busch, L. Conversi, R. Kresken, and
M. Micheli using the 1.0-m f/4.4 reflector, noting only that no tail was
visible.  Confirming observations with the same telescope on Feb. 14.0, taken
in 3".5 seeing, show a small coma of size 5".3 (full-width-at-half-maximum)
in ten 60-s stacked exposures.  The astrometry is tabulated below.

     2024 UT             R.A. (2000) Decl.       Mag.   Observer
     Feb. 12.97344    8 57 57.15   +23 02 11.9   20.2   Schwab
          12.97796    8 57 56.99   +23 02 12.2   20.5     "
          12.98402    8 57 56.77   +23 02 13.3   20.5     "
          12.98931    8 57 56.54   +23 02 14.3   20.3     "
          14.00707    8 57 17.81   +23 05 34.0   20.6     "
          14.01499    8 57 17.47   +23 05 35.9   20.4     "
          14.02289    8 57 17.18   +23 05 36.2   20.8     "

     S. Deen (Simi Valley, CA, USA) writes that, as a result of the Minor
Planet Center posting this recovery pre-publication on their new webpage (URL
https://www.minorplanetcenter.net/iau/recovery/recovery.html), he searched
for additional observations in publicly available online data, from which he
found single-image observations obtained with the Cerro Tololo 4-m reflector
(+ DECam) on 2022 Sept. 18 and 19.  Deen notes that the comet was very faint
(mag 21.6-22.0) and essentially stellar in appearance.  His astrometry
appears on MPEC 2024-D103.
     The residuals of Schwab's recovery observations are +145" in R.A. and
-30" in Decl. from the prediction in NK 2406 (and the ICQ's 2023 Comet
Handbook), with a correponding correction of Delta(T) = -0.16 day.  The
following linked orbital elements by S. Nakano (Central Bureau) are from 39
observations spanning 2011 Sept. 26-2024 Feb. 14 (mean residual 0".4).  There
are no close approaches to major planets.

                    Epoch = 2013 Jan. 28.0 TT
     T = 2013 Jan. 24.74500 TT        Peri. = 353.15904
     e = 0.3396577                    Node  =  94.52353 2000.0
     q = 3.1734284 AU                 Incl. =   6.11884
       a =  4.8057323 AU   n = 0.09355451   P =  10.54 years

                    Epoch = 2023 June 25.0 TT
     T = 2023 July  8.64003 TT        Peri. = 356.63762
     e = 0.3434109                    Node  =  93.55606 2000.0
     q = 3.0714282 AU                 Incl. =   6.08283
       a =  4.6778545 AU   n = 0.09741683   P =  10.12 years

                    Epoch = 2033 Aug. 31.0 TT
     T = 2033 Aug. 30.70410 TT        Peri. = 356.68840
     e = 0.3426126                    Node  =  93.56254 2000.0
     q = 3.0899997 AU                 Incl. =   6.07571
       a =  4.7004244 AU   n = 0.09671603   P =  10.19 years

                    Epoch = 2043 Nov.  7.0 TT
     T = 2043 Nov. 26.19701 TT        Peri. = 356.74452
     e = 0.3414067                    Node  =  93.49090 2000.0
     q = 3.1113031 AU                 Incl. =   6.06787
       a =  4.7241643 AU   n = 0.09598792   P =  10.27 years

The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 12.5 and 2.5n = 10 for the
magnitudes.

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase  Mag.
2024 01 11    09 18.75   +20 43.2    2.336    3.248   153.8     7.7  19.5
2024 01 21    09 13.17   +21 28.2    2.306    3.266   165.0     4.5  19.5
2024 01 31    09 06.63   +22 12.5    2.304    3.285   174.1     1.8  19.5
2024 02 10    08 59.88   +22 51.9    2.331    3.305   169.0     3.3  19.5
2024 02 20    08 53.72   +23 23.1    2.387    3.325   158.1     6.4  19.6
2024 03 01    08 48.83   +23 44.2    2.470    3.346   147.2     9.2  19.7
2024 03 11    08 45.68   +23 54.5    2.577    3.368   136.6    11.7  19.8
2024 03 21    08 44.53   +23 54.5    2.703    3.390   126.4    13.7  20.0
2024 03 31    08 45.43   +23 45.1    2.843    3.413   116.8    15.1  20.1
2024 04 10    08 48.27   +23 27.4    2.996    3.436   107.8    16.1  20.2
2024 04 20    08 52.88   +23 02.2    3.155    3.460    99.2    16.7  20.4
2024 04 30    08 59.03   +22 30.4    3.319    3.485    91.0    16.8  20.5
2024 05 10    09 06.48   +21 52.7    3.484    3.509    83.1    16.6  20.7
2024 05 20    09 15.02   +21 09.5    3.647    3.534    75.6    16.1  20.8
2024 05 30    09 24.44   +20 21.4    3.806    3.560    68.4    15.4  20.9
2024 06 09    09 34.55   +19 28.9    3.959    3.586    61.4    14.4  21.0
2024 06 19    09 45.23   +18 32.2    4.105    3.612    54.6    13.3  21.1
2024 06 29    09 56.31   +17 32.0    4.241    3.639    47.9    12.0  21.2
2024 07 09    10 07.71   +16 28.7    4.367    3.666    41.4    10.6  21.3


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

                         (C) Copyright 2024 CBAT
2024 February 22                 (CBET 5356)              Daniel W. E. Green