Electronic Telegram No. 5172
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 R3 (LEONARD)
Gregory J. Leonard, University of Arizona, reports his discovery of
another comet on CCD images obtained on Sept. 15 with the Mt. Lemmon 1.5-m
reflector. Leonard noted that four 30-s stacked images show a moderately
condensed coma 6" across with a straight tail about 10" long in p.a. 240
degrees.
2022 UT R.A. (2000) Decl. Mag. Observer
Sept.15.35780 3 26 59.83 +55 37 59.8 18.9 Leonard
15.36437 3 26 59.97 +55 38 04.1 19.8 "
15.36955 3 26 59.98 +55 38 07.1 19.6 "
15.37622 3 26 59.94 +55 38 11.2 19.6 "
15.47687 3 26 59.86 +55 39 10.4 19.6 "
15.48679 3 26 59.88 +55 39 16.6 19.8 "
15.49686 3 26 59.83 +55 39 21.9 "
After the comet was posted to the Minor Planet Center's PCCP webpage, other
CCD astrometrists also sent reports of cometary appearance to the Central
Bureau. K. Wierzchos, University of Arizona, reports that three 45-s
exposures taken with the discovery telescope on Sept. 18.4 UT show a very
condensed coma of size 7" and a straight 18" tail in p.a. 240 degrees. Ninety
60-s exposures taken on Sept. 19.1 by L. Buzzi, Varese, Italy, with a 0.84-m
f/3.5 reflector (and measured by A. Aletti) show a condensed 8" coma and a
faint tail 10" long in p.a. 250 degrees; thirty stacked 60-s follow-up
exposurse taken on Sept. 20.14-20.15 show a condensed 6" coma and a tail 9"
long in p.a. 225 degrees. F. Kugel, Dauban, France, writes that eleven 120-s
unfiltered exposures taken on Sept. 19.1 with a 0.4-m f/2.8 reflector show a
possible tail 15" long in p.a. 225 degrees; the magnitude was measured to be
19.7-20.0 in an aperture of radius 5".8. Fifty-one luminance-filtered
stacked 120-s exposures taken between Sept. 21.89 and 21.96 with a 0.4-m
f/3.8 reflector by E. Bryssinck, Kruibeke, Belgium, show a strongly condensed
coma 7" in diameter with a hint of a tail 9" long in p.a. 247 degrees; the
magnitude was 20.3-20.4 as measured within a circular aperture of radius 5".5.
Eight stacked 120-s exposures taken remotely on Sept. 22.5 by H. Sato
(Bunkyo-ku, Tokyo, Japan) with a 0.43-m f/6.8 astrograph located at Mayhill,
NM, USA, show a strongly condensed coma 8" in diameter with no tail; the
magnitude was 18.9 as measured within a circular aperture of radius 5".7.
The available astrometry appears on MPEC 2022-S250. The following
parabollic orbital elements by S. Nakano (Central Bureau) are from 77
observations spanning Sept. 15-23 (mean residual 0".6).
T = 2023 Feb. 16.68885 TT Peri. = 70.86764
Node = 8.18588 2000.0
q = 5.1571533 AU Incl. = 43.05686
The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 9.5 and 2.5n = 8 for the
magnitudes.
Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag.
2022 08 09 03 14.87 +49 19.3 5.478 5.356 77.8 10.7 19.0
2022 08 19 03 20.10 +51 01.2 5.331 5.337 84.9 10.9 19.0
2022 08 29 03 24.04 +52 43.5 5.187 5.318 92.0 10.9 18.9
2022 09 08 03 26.41 +54 24.9 5.047 5.300 99.1 10.8 18.8
2022 09 18 03 26.95 +56 03.8 4.915 5.283 106.1 10.5 18.7
2022 09 28 03 25.40 +57 37.9 4.795 5.267 113.0 10.1 18.7
2022 10 08 03 21.59 +59 04.4 4.688 5.252 119.5 9.5 18.6
2022 10 18 03 15.53 +60 20.1 4.598 5.239 125.4 8.9 18.6
2022 10 28 03 07.43 +61 21.6 4.527 5.226 130.4 8.3 18.5
2022 11 07 02 57.82 +62 06.1 4.477 5.214 134.0 7.9 18.5
2022 11 17 02 47.51 +62 32.2 4.449 5.204 135.8 7.6 18.5
2022 11 27 02 37.47 +62 39.9 4.444 5.194 135.5 7.7 18.5
2022 12 07 02 28.70 +62 31.3 4.461 5.186 133.2 8.0 18.5
2022 12 17 02 21.97 +62 10.1 4.499 5.178 129.3 8.5 18.5
2022 12 27 02 17.77 +61 40.4 4.556 5.172 124.1 9.1 18.5
2023 01 06 02 16.32 +61 06.7 4.629 5.167 118.2 9.7 18.5
2023 01 16 02 17.60 +60 32.7 4.717 5.163 111.8 10.2 18.6
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2022 CBAT
2022 September 26 (CBET 5172) Daniel W. E. Green