Electronic Telegram No. 5127
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/2022 K1 (LEONARD)
     Gregory J. Leonard, University of Arizona, reports his discovery of
another comet on CCD images obtained on May 30 with the Mt. Lemmon 1.5-m
reflector (discovery observations tabulated below); four co-added 30-s
exposures show a moderately condensed coma 24" across with no apparent tail.

     2022 UT             R.A. (2000) Decl.       Mag.   Observer
     May  30.41297   21 29 44.52   - 7 15 11.5   19.7   Leonard
          30.41823   21 29 44.61   - 7 15 12.4   20.3     "
          30.42350   21 29 44.68   - 7 15 13.7   19.9     "
          30.42876   21 29 44.78   - 7 15 15.2   20.0     "

After the comet was posted on the Minor Planet Center's PCCP webpage, other
CCD astrometrists have commented on the physical appearance.  Eight stacked
120-s exposures taken remotely by H. Sato (Tokyo, Japan) with a 0.51-m f/6.8
astrograph located at Mayhill, NM, USA, on June 1.4 UT show a stellar
appearance; the magnitude was 20.4 as measured within a circular aperture of
radius 4".9.  R. Weryk, Department of Physics and Astronomy, University of
Western Ontario, writes that two 45-s w-band survey images obtained with the
Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala, HI, on June 1.6
show a diffuse cmoa of size 2".3 (full-width-at-half-maximum) in 1".4 seeing;
there was no clear tail, but the point-spread function suggests the
possibility of asymmetry toward the southwest.  Ten stacked 60-s exposures
taken remotely by F. D. Romanov with the robotic 2.0-m f/10 Ritchey-Chretien
Liverpool Telescope (+ Sloan r' filter) at La Palama on June 3.11 show a
condensed coma 8" in diameter and of mag 20.4 with no tail.
     The available astrometry appears on MPEC 2022-L53.  The following
preliminary parabolic orbital elements by S. Nakano (Central Bureau) are from
27 observations spanning May 30-June 5 (mean residual 0".2).

     T = 2021 Dec. 17.24143 TT        Peri. = 142.61034
                                      Node  = 136.28710 2000.0
     q = 3.9839132 AU                 Incl. =  41.96827

The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 11.5 and 2.5n = 8 for the
magnitudes.

Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase  Mag.
2022 05 21    21 26.51   -06 40.9    3.942    4.199    97.7    13.8  19.5
2022 05 31    21 29.90   -07 17.6    3.823    4.227   106.7    13.3  19.4
2022 06 10    21 31.92   -08 05.5    3.712    4.256   116.0    12.4  19.4
2022 06 20    21 32.56   -09 05.0    3.613    4.287   125.7    11.1  19.3
2022 06 30    21 31.83   -10 16.1    3.531    4.318   135.8     9.4  19.3
2022 07 10    21 29.84   -11 37.6    3.469    4.352   146.3     7.5  19.3
2022 07 20    21 26.79   -13 07.5    3.433    4.386   157.0     5.2  19.3
2022 07 30    21 22.95   -14 42.7    3.424    4.422   168.0     2.7  19.3
2022 08 09    21 18.69   -16 19.4    3.445    4.459   178.9     0.3  19.4
2022 08 19    21 14.42   -17 53.5    3.498    4.497   169.7     2.3  19.4
2022 08 29    21 10.54   -19 21.5    3.580    4.537   158.7     4.6  19.5
2022 09 08    21 07.43   -20 40.5    3.692    4.577   147.9     6.7  19.6
2022 09 18    21 05.38   -21 48.9    3.828    4.618   137.4     8.5  19.7


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

                         (C) Copyright 2021 CBAT
2021 June 7                      (CBET 5127)              Daniel W. E. Green