[Iaude] CBET 4800: COMET P/2020 M1

[quai at eps.harvard.edu]

                                                  Electronic Telegram No. 4800
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/2020 M1 (PANSTARRS)
     Y. Ramanjooloo, Institute for Astronomy, University of Hawaii, reports
the discovery of another comet in images obtained on June 17 with the
Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala, the comet noted
then as being very condensed with a 1".4 coma (in 1".0 seeing) and a straight
3".8 tail in p.a. 228 degrees.  The discovery astrometry is tabulated below,
along with pre-discovery Pan-STARRS2 1.8-m reflector observations on May 24
and June 11 and pre-discovery Pan-STARRS1 observations on May 28.

     2020 UT             R.A. (2000) Decl.       Mag.
     May  24.44616   17 04 22.79   -10 18 02.2   21.1
          24.45802   17 04 22.31   -10 18 02.1   20.4
          24.46989   17 04 21.87   -10 18 01.4   21.4
          28.41690   17 01 54.54   -10 16 09.5   21.1
          28.42917   17 01 54.03   -10 16 09.3   21.3
          28.44145   17 01 53.56   -10 16 09.1   21.4
     June 11.36424   16 52 57.95   -10 21 35.8   20.7
          11.37549   16 52 57.50   -10 21 36.9   21.0
          11.38675   16 52 57.06   -10 21 37.8   20.6
          11.39808   16 52 56.62   -10 21 38.1   21.0
          17.36562   16 49 21.51   -10 29 48.2   21.3
          17.37750   16 49 21.08   -10 29 49.5   21.4
          17.38936   16 49 20.65   -10 29 50.6   21.2
          17.40121   16 49 20.22   -10 29 51.6   21.1

R. Weryk, University of Hawaii, reports on follow-up CCD observations
obtained on two nights with the 3.6-m Canada-France-Hawaii Telescope at Mauna
Kea by R. Wainscoat, H. Januszewski, and S. Prunet that show this object to
be clearly a comet:  On June 29.3 UT, six 60-s gri-band images show a short
tail extending for about 2" toward the southwest; the comet's head was 1".0
across (full-width-at-half-maximum) in 0".8 seeing.  On June 21.3, three 60-s
gri-band images again show a tail about 2" long toward the southwest, and
the comoet's head was 1".2 across (FWHM) in 0".9 seeing.
     The available astrometry appear on MPEC 2020-M76.  The following
preliminary elliptical orbital elements by S. Nakano, Sumoto, Japan, are from
25 observations spanning 2020 May 24-June 21 (mean residual 0".2), and they
indicate that the comet will pass 0.69 AU from Jupiter in 2021 October.

     T = 2019 Dec. 21.0474 TT         Peri. =  67.8218
     e = 0.477144                     Node  = 142.9594  2000.0
     q = 2.660457 AU                  Incl. =   8.6324
       a =  5.088320 AU    n = 0.0858702    P =  11.48 years

The following ephemeris by the undersigned from the above elements use
photometry power-law parameters H = 14.5 and 2.5n = 10 for the magnitudes.

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase  Mag.
2020 04 21    17 16.12   -11 18.6    2.038    2.802   131.0    15.7  20.5
2020 05 01    17 14.89   -10 54.3    1.974    2.825   140.5    13.1  20.5
2020 05 11    17 11.52   -10 34.3    1.929    2.850   150.2    10.1  20.5
2020 05 21    17 06.42   -10 20.8    1.905    2.875   159.5     7.1  20.5
2020 05 31    17 00.26   -10 15.7    1.907    2.903   166.6     4.7  20.5
2020 06 10    16 53.82   -10 20.2    1.934    2.931   166.5     4.6  20.6
2020 06 20    16 47.88   -10 34.5    1.987    2.961   159.5     6.9  20.7
2020 06 30    16 43.13   -10 58.0    2.065    2.991   150.4     9.7  20.8
2020 07 10    16 40.06   -11 29.6    2.165    3.023   140.9    12.2  21.0
2020 07 20    16 38.92   -12 07.5    2.284    3.056   131.6    14.4  21.1
2020 07 30    16 39.81   -12 49.9    2.420    3.089   122.7    16.1  21.3
2020 08 09    16 42.68   -13 35.1    2.569    3.124   114.1    17.2  21.5
2020 08 19    16 47.39   -14 21.3    2.728    3.159   105.9    17.9  21.7
2020 08 29    16 53.77   -15 07.1    2.894    3.195    98.0    18.2  21.9
2020 09 08    17 01.63   -15 51.2    3.064    3.231    90.3    18.2  22.0
2020 09 18    17 10.78   -16 32.5    3.236    3.268    82.9    17.8  22.2
2020 09 28    17 21.05   -17 10.0    3.408    3.306    75.7    17.1  22.4


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

                         (C) Copyright 2020 CBAT
2020 June 23                     (CBET 4800)              Daniel W. E. Green