Electronic Telegram No. 5054
Central Bureau for Astronomical Telegrams
Mailing address:  Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2021 T2 (FULS)
     D. C. Fuls reports the discovery of a comet in survey images taken on
Oct. 2 UT with the 1.5-m reflector of the Mt. Lemmon Survey, noting a
condensed 7".5 coma; the discovery observations are tabulated below.

     2021 UT             R.A. (2000) Decl.       Mag.   Observer
     Oct.  2.37616    4 12 26.31   +46 16 03.0   19.8   Fuls
           2.38157    4 12 26.00   +46 16 02.4   20.0     "
           2.38701    4 12 25.61   +46 16 01.5   20.1     "
           2.39244    4 12 25.23   +46 16 01.0   20.3     "
           2.45776    4 12 20.59   +46 15 54.2   20.0     "
           2.46541    4 12 20.09   +46 15 53.4   20.2     "
           2.47249    4 12 19.55   +46 15 52.4            "
           2.47979    4 12 19.03   +46 15 51.3            "

After the comet was posted on the Minor Planet Center's PCCP webpage, H. Sato,
Tokyo, Japan, reported a strongly condensed coma 6" in diameter with no tail
on fourteen stacked 60-s CCD exposures taken remotely on Oct. 4.3 UT with a
0.43-m f/6.8 astrograph located near Mayhill, NM, USA; the magnitude was 19.6
as measured within a circular aperture of radius 5".7.
     The available astrometry appears on MPEC 2021-T169.  The following
preliminary parabolic orbital elements by S. Nakano (CBAT) are from 34
observations spanning Oct. 2-7 (mean residual 0".5).

     T = 2022 June  7.92170 TT        Peri. = 263.60465
                                      Node  = 223.23154 2000.0
     q = 1.2475362 AU                 Incl. = 117.52665

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.
2021 09 23    04 21.32   +46 24.9    3.201    3.618   106.6    15.4  20.0
2021 10 03    04 11.71   +46 14.9    2.945    3.514   117.0    14.7  19.7
2021 10 13    03 57.64   +45 44.3    2.704    3.410   127.9    13.3  19.4
2021 10 23    03 38.98   +44 40.8    2.486    3.304   139.2    11.3  19.1
2021 11 02    03 16.32   +42 50.5    2.300    3.199   150.0     8.9  18.8
2021 11 12    02 51.20   +40 01.7    2.155    3.092   157.3     7.1  18.6
2021 11 22    02 25.98   +36 12.9    2.057    2.985   155.6     7.9  18.4
2021 12 02    02 02.98   +31 36.5    2.010    2.877   145.5    11.2  18.2
2021 12 12    01 43.84   +26 37.1    2.011    2.769   132.1    15.3  18.1
2021 12 22    01 29.25   +21 41.6    2.052    2.660   118.0    19.0  18.0
2022 01 01    01 19.09   +17 09.7    2.124    2.552   104.3    21.9  17.9
2022 01 11    01 12.89   +13 11.3    2.212    2.443    91.4    23.7  17.8
2022 01 21    01 10.02   +09 47.6    2.307    2.334    79.3    24.5  17.8


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

                         (C) Copyright 2021 CBAT
2021 October 9                   (CBET 5054)              Daniel W. E. Green