[Iaude] CBET 5349: COMET C/2024 A2

[quai at eps.harvard.edu]

                                                  Electronic Telegram No. 5349
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/2024 A2 (ATLAS)
     An apparently asteroidal object discovered on CCD images taken on
Jan. 15 UT with a 0.5-m f/2 Schmidt reflector at Rio Hurtado, Chile, in
the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS)
search program has been found to show cometary appearance by CCD
astrometrists elsewhere after it was posted to the Minor Planet Center's
PCCP webpage.  The discovery observations are tabulated below:

     2024 UT             R.A. (2000) Decl.       Mag.
     Jan. 15.33554   14 52 55.63   -65 17 49.7   18.0
          15.34072   14 52 55.44   -65 17 59.6   18.0
          15.36106   14 52 54.89   -65 18 36.2   17.8
          15.36879   14 52 54.70   -65 18 49.4   17.8

Eight stacked 30-s CCD exposures taken remotely by H. Sato (Bunkyo-ku, Tokyo,
Japan) on Jan. 16.35 UT with a "Deep Sky Chile" 0.51-m f/6.8 astrograph
located at Rio Hurtado, Chile, show a strongly condensed round coma 5" in
diameter with no tail; the magnitude was 18.1 as measured within a circular
aperture of radius 2".8.  Six stacked 60-s exposures taken remotely by Sato
on Feb. 10.7 with a 0.51-m f/6.8 astrograph located at Siding Spring, NSW,
Australia, show a strongly condensed coma 6" in diameter and no tail; the
magnitude was 17.7 as measured within a circular aperture of radius 4".9.
Exposures taken remotely on Feb. 9.75 by T. Prystavski (Lyiv, Ukraine) with a
0.43-m f/6.8 corrected Dall-Kirkham telescope at Siding Spring show a very
condensed head of total mag 17.7 that is slightly elongated with a possible
0'.1 tail in p.a. 40 degrees.
     The available astrometry appears on MPEC 2024-C180.  The following two-
body orbital elements by S. Nakano (Central Bureau) are from 115 observations
spanning 2024 Jan. 15-Feb. 14 (mean residual 0".4).  They indicate no close
approaches to major planets; the orbital period has a formal error of +/- 2.1
years.

     T = 2024 Apr. 28.87857 TT        Peri. = 295.56302
     e = 0.9421865                    Node  =  78.16308 2000.0
     q = 1.8818119 AU                 Incl. = 119.10889
       a = 32.5497004 AU   n = 0.00530742   P = 185.7 years

The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 13.0 and 2.5n = 8 for the
magnitudes.

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase  Mag.
2024 01 11    14 54.14   -63 12.8    2.603    2.287    60.6    22.0  18.0
2024 01 16    14 52.62   -65 37.8    2.503    2.255    64.2    23.1  17.8
2024 01 21    14 48.99   -68 15.6    2.402    2.223    67.7    24.2  17.7
2024 01 26    14 41.99   -71 06.6    2.304    2.193    71.1    25.1  17.5
2024 01 31    14 29.17   -74 10.0    2.208    2.164    74.5    26.0  17.4
2024 02 05    14 05.23   -77 22.1    2.116    2.135    77.7    26.8  17.3
2024 02 10    13 17.59   -80 30.0    2.030    2.108    80.7    27.5  17.1
2024 02 15    11 39.22   -82 51.2    1.951    2.082    83.3    28.1  17.0
2024 02 20    09 09.76   -82 50.1    1.881    2.057    85.6    28.6  16.9
2024 02 25    07 20.74   -79 57.3    1.822    2.034    87.4    29.1  16.8
2024 03 01    06 27.18   -75 32.7    1.776    2.012    88.6    29.5  16.7
2024 03 06    06 00.55   -70 26.1    1.743    1.992    89.1    29.9  16.6
2024 03 11    05 46.40   -64 58.8    1.725    1.973    88.8    30.2  16.5
2024 03 16    05 38.70   -59 23.0    1.722    1.956    87.8    30.5  16.5
2024 03 21    05 34.66   -53 48.0    1.733    1.940    86.1    30.8  16.5
2024 03 26    05 32.88   -48 21.1    1.759    1.926    83.8    31.0  16.5
2024 03 31    05 32.58   -43 07.9    1.797    1.914    81.0    31.0  16.5
2024 04 05    05 33.30   -38 12.6    1.847    1.904    77.7    30.9  16.6
2024 04 10    05 34.74   -33 37.5    1.906    1.896    74.2    30.6  16.6
2024 04 15    05 36.72   -29 23.8    1.972    1.889    70.4    30.0  16.7
2024 04 20    05 39.09   -25 31.3    2.045    1.885    66.5    29.3  16.8
2024 04 25    05 41.74   -21 59.0    2.121    1.882    62.5    28.3  16.8
2024 04 30    05 44.62   -18 45.8    2.200    1.882    58.5    27.2  16.9
2024 05 05    05 47.68   -15 50.0    2.280    1.883    54.5    25.9  17.0
2024 05 10    05 50.86   -13 09.9    2.359    1.887    50.6    24.4  17.1
2024 05 15    05 54.15   -10 44.1    2.437    1.892    46.6    22.9  17.1
2024 05 20    05 57.50   -08 31.0    2.513    1.899    42.8    21.2  17.2
2024 05 25    06 00.90   -06 29.1    2.586    1.908    39.0    19.5  17.3
2024 05 30    06 04.32   -04 37.2    2.654    1.919    35.4    17.8  17.4

2024 08 18    06 50.33   +13 58.9    2.926    2.302    43.6    17.7  18.2
2024 08 28    06 52.62   +15 54.2    2.846    2.370    52.4    19.8  18.3
2024 09 07    06 53.26   +17 56.9    2.747    2.440    61.9    21.4  18.3
2024 09 17    06 51.75   +20 11.0    2.633    2.513    72.1    22.4  18.3
2024 09 27    06 47.48   +22 40.2    2.510    2.589    83.1    22.6  18.3
2024 10 07    06 39.68   +25 27.0    2.387    2.666    94.9    21.9  18.3
2024 10 17    06 27.42   +28 31.3    2.273    2.745   107.6    20.2  18.3
2024 10 27    06 09.82   +31 47.6    2.178    2.825   121.2    17.5  18.3
2024 11 06    05 46.26   +35 02.7    2.115    2.906   135.4    13.9  18.3
2024 11 16    05 17.12   +37 56.0    2.096    2.988   149.0     9.8  18.4
2024 11 26    04 44.27   +40 05.6    2.127    3.070   159.3     6.5  18.5


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

                         (C) Copyright 2024 CBAT
2024 February 15                 (CBET 5349)              Daniel W. E. Green