[Iaude] CBET 4796: COMET C/2020 K8

quai at eps.harvard.edu quai at eps.harvard.edu
Fri Jun 12 12:32:17 EDT 2020


                                                  Electronic Telegram No. 4796
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/2020 K8 (CATALINA-ATLAS)
     Independent discoveries of an apparently asteroidal object (discovery
observations tabulated below) have been made on CCD images taken with the
0.68-m Schmidt telescope of the Catalina Sky Survey (on May 25, 28, and 29)
and the 0.5-m f/2 Schmidt reflector at Haleakala, Hawaii, in the course of the
"Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program (on
June 7), and the object has been found to show cometary appearance
subsequently by numerous CCD astrometrists at other observing sites after the
object was posted on the Minor Planet Center's PCCP webpage (due to its
orbital elements, following a linkage of the separately posted four nights
by R. Weryk, University of Hawaii).

     2020 UT             R.A. (2000) Decl.       Mag.   Observer
     May  25.43424   22 50 45.88   +15 31 37.1   19.3   Catalina
          25.43832   22 50 46.29   +15 31 40.6   19.6     "
          25.44238   22 50 46.68   +15 31 43.8   19.2     "
          25.44645   22 50 47.12   +15 31 45.9   19.1     "
          28.44403   22 55 43.96   +16 08 30.8   19.3     "
          28.44933   22 55 44.60   +16 08 36.2   19.0     "
          28.45462   22 55 45.08   +16 08 40.2   19.1     "
          28.45992   22 55 45.58   +16 08 44.8   19.2     "
          29.40536   22 57 21.20   +16 20 32.6   18.8     "
          29.41066   22 57 21.80   +16 20 35.8   19.4     "
          29.41595   22 57 22.26   +16 20 39.8   19.2     "
          29.42125   22 57 22.78   +16 20 44.2   18.9     "
     June  7.56494   23 13 40.17   +18 20 27.5   18.7   ATLAS
           7.57711   23 13 41.58   +18 20 37.3   18.6     "
           7.60122   23 13 44.37   +18 20 57.3   18.6     "
           7.60675   23 13 44.94   +18 21 03.2   18.6     "

E. Guido, Castellammare di Stabia, Italy, reports that twenty-nine unfiltered,
stacked 60-s exposures taken remotely by M. Rocchetto, E. Bryssinck, M. Fulle,
G. Milani, C. Nassef, G. Savini, and himself on June 9.4 UT with a "Telescope
Live" 0.6-m f/6.5 astrograph at El Sauce, Chile, show a diffuse, irregular
coma about 10" in diameter; they measured mag 19.1-19.2.  Twenty-four stacked
57-s unfiltered exposures taken by A. Valvasori and Guido on June 10.4 with
an iTelescope 0.61-m f/6.5 astrograph near Auberry, CA, USA, show a diffuse
coma about 15" in diameter (mag 18.1-18.7), slightly elongated toward p.a.
330 degrees.  R. Ligustri writes that eleven 120-s exposures taken remotely
with a 0.45-m f/4.5 telescope near Mayhill, NM, USA, on June 10.4 show a
coma about 25" in diameter.  G. Leonard writes that four stacked 30-s images
taken on June 11.4 with the University of Arizona's 1.54-m telescope at Mt.
Bigelow show a diffuse, concentric coma about 20" across surrounding an
obvious zone of central brightening that is about 8" across.  Fourteen
stacked 60-s exposures taken remotely by H. Sato, Tokyo, Japan, with a 0.43-m
f/6.8 astrograph near Mayhill on June 11.4 show a strongly condensed round
coma 8" in diameter and no tail; the magnitude was 18.8 as measured within a
circular aperture of radius 5".7.
     The available astrometry appear on MPEC 2020-L46.  The following
preliminary parabolic orbital elements by S. Nakano, Sumoto, Japan, are from
64 observations spanning May 25-June 12 (mean residual 0".5).

     T = 2020 Sept.14.4988 TT         Peri. = 260.1120
                                      Node  = 181.4946  2000.0
     q = 0.474139 AU                  Incl. =  31.4230

The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 15.0 and 2.5n = 7.5 for the
magnitudes.

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase  Mag.
2020 04 21    22 00.57   +09 32.7    3.062    2.664    57.7    18.6  20.6
2020 04 26    22 07.34   +10 18.3    2.941    2.596    60.4    19.7  20.5
2020 05 01    22 14.24   +11 05.9    2.819    2.528    63.1    20.8  20.3
2020 05 06    22 21.29   +11 55.7    2.696    2.459    65.7    22.0  20.1
2020 05 11    22 28.52   +12 47.7    2.572    2.388    68.2    23.1  19.9
2020 05 16    22 35.97   +13 42.1    2.446    2.318    70.7    24.3  19.7
2020 05 21    22 43.67   +14 39.0    2.321    2.246    73.1    25.5  19.5
2020 05 26    22 51.68   +15 38.5    2.195    2.173    75.4    26.8  19.2
2020 05 31    23 00.07   +16 40.7    2.069    2.100    77.6    28.1  19.0
2020 06 05    23 08.91   +17 45.8    1.944    2.026    79.7    29.5  18.7
2020 06 10    23 18.33   +18 54.1    1.819    1.950    81.7    31.0  18.5
2020 06 15    23 28.48   +20 05.9    1.695    1.874    83.4    32.6  18.2
2020 06 20    23 39.53   +21 21.4    1.573    1.797    85.0    34.3  17.9
2020 06 25    23 51.73   +22 40.9    1.452    1.718    86.3    36.2  17.6
2020 06 30    00 05.44   +24 04.3    1.334    1.639    87.3    38.3  17.2
2020 07 05    00 21.11   +25 31.8    1.218    1.558    87.9    40.7  16.9
2020 07 10    00 39.40   +27 02.7    1.106    1.476    88.0    43.5  16.5
2020 07 15    01 01.19   +28 35.2    0.999    1.393    87.4    46.8  16.1
2020 07 20    01 27.63   +30 05.0    0.898    1.309    86.0    50.8  15.6
2020 07 25    02 00.21   +31 23.0    0.806    1.223    83.5    55.6  15.2
2020 07 30    02 40.52   +32 12.2    0.724    1.137    79.7    61.5  14.7
2020 08 04    03 29.47   +32 04.8    0.659    1.049    74.2    68.6  14.3
2020 08 09    04 25.96   +30 26.5    0.615    0.961    67.2    76.6  13.8
2020 08 14    05 25.78   +26 57.2    0.598    0.873    59.1    84.9  13.4
2020 08 19    06 23.14   +21 55.9    0.611    0.785    50.8    92.1  13.1
2020 08 24    07 13.99   +16 17.5    0.655    0.701    43.5    96.4  12.9
2020 08 29    07 57.50   +10 57.5    0.727    0.621    37.7    96.7  12.8
2020 09 03    08 35.01   +06 26.8    0.823    0.552    33.2    92.2  12.6
2020 09 08    09 08.56   +02 54.1    0.936    0.501    29.6    83.1  12.6
2020 09 13    09 39.82   +00 15.5    1.061    0.476    26.4    70.3  12.7
2020 09 18    10 09.55   -01 38.8    1.189    0.482    23.5    56.3  13.0
2020 09 23    10 37.64   -03 00.8    1.312    0.519    20.9    43.7  13.5
2020 09 28    11 03.67   -04 01.5    1.428    0.578    18.8    33.9  14.0


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

                         (C) Copyright 2020 CBAT
2020 June 12                     (CBET 4796)              Daniel W. E. Green



More information about the Iaude mailing list