[Iaude] CBET 5304: COMET C/2023 T2
quai at eps.harvard.edu
quai at eps.harvard.edu
Sat Oct 21 12:40:21 EDT 2023
Electronic Telegram No. 5304
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/2023 T2 (BORISOV)
Gennady Borisov reports his discovery of another comet on CCD images
obtained on Oct. 14 with a 0.50-m f/1.9 astrograph at the MARGO observatory
near Nauchnij, Crimea (discovery observations tabulated below). The object
showed a diffuse coma of diameter about 4" with no tail; Borisov measured the
total green magnitude of the comet to be 19.4 in a circular aperture of size
0'.5.
2023 UT R.A. (2000) Decl. Mag. Observer
Oct. 14.69480 21 21 48.86 +75 33 26.3 19.4 Borisov
14.69797 21 21 47.94 +75 33 26.4 19.1 "
14.70124 21 21 47.20 +75 33 27.1 19.2 "
14.73236 21 21 38.97 +75 33 31.8 19.6 "
14.73663 21 21 37.87 +75 33 31.9 19.7 "
14.74090 21 21 36.75 +75 33 32.4 19.6 "
14.76799 21 21 29.72 +75 33 35.5 19.7 "
14.77636 21 21 27.54 +75 33 36.6 19.6 "
After the object was posted on the Minor Planet Center's PCCP webpage, other
CCD astrometrists confirmed the cometary appearance. Twelve stacked 60-s
exposures taken remotely by H. Sato (Bunkyo-ku, Tokyo, Japan) on Oct. 16.1 UT
with a 0.51-m f/6.8 astrograph located at the Utah Desert Remote Observatory
(near Beryl Junction, UT, USA) show a strongly condensed coma 6" in diameter
with no tail; the magnitude was 19.3 as measured within a circular aperture
of radius 4".9. D. Buczynski (Portmahomack, Scotland) reports that
twenty-four 90-s stacked images taken on Oct. 16.95-16.97 with a 0.35-m f/6
Schmidt-Cassegrain reflector show a 15" tail in p.a. 115 degrees. Sixty-two
stacked 30-s exposures taken by A. Aletti with a 0.36-m f/7.5 reflector at
Varese, Italy, on Oct. 17.1 (measured by Aletti and M. Auteri) show a
condensed coma 6" wide of magnitude 19.0, extended toward the east.
Following a request by the Central Bureau, W. Ryan writes that exposures
taken with the Magdalena Ridge Observatory 2.4-m reflector on Oct. 19.13 UT
show this object to be clearly a comet; there is a 6" diffuse coma with a
broad, diffuse tail about 18" long spanning p.a. 90-130 degrees that is
visible in single images.
Also in response to a request from the Central Bureau, R. Weryk
(Department of Physics and Astronomy, University of Western Ontario) finds a
very condensed head of size 1".8 (full-width-at-half-msximum) in 1".1 seeing,
and a 5" tail in p.a. 120 degrees, in two 60-s w-band images obtained on Oct.
19.2 UT with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala.
The available astrometry appears on MPEC 2023-U162. The following
parabolic orbital elements by S. Nakano (Central Bureau) are from 152
observations spanning 2023 Oct. 14-20 (mean residual 0".4). These indicate
that the comet passed 1.86 AU from Saturn in 2021 May and 3.51 AU from
Jupiter in 2022 April.
T = 2023 Dec. 21.38496 TT Peri. = 110.02411
Node = 318.00684 2000.0
q = 2.0130912 AU Incl. = 48.78699
The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 14.5 and 2.5n = 8 for the
magnitudes.
Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag.
2023 09 13 23 28.37 +68 58.6 1.838 2.338 106.9 24.3 18.8
2023 09 18 23 13.82 +70 43.4 1.806 2.309 107.0 24.6 18.7
2023 09 23 22 56.45 +72 14.1 1.777 2.281 106.9 24.9 18.6
2023 09 28 22 36.50 +73 28.7 1.752 2.254 106.7 25.2 18.5
2023 10 03 22 14.56 +74 26.1 1.729 2.228 106.3 25.5 18.5
2023 10 08 21 51.65 +75 05.9 1.708 2.203 105.9 25.9 18.4
2023 10 13 21 29.12 +75 29.0 1.689 2.180 105.5 26.2 18.3
2023 10 18 21 08.31 +75 37.8 1.672 2.157 105.1 26.5 18.3
2023 10 23 20 50.30 +75 35.7 1.656 2.137 104.6 26.8 18.2
2023 10 28 20 35.72 +75 26.5 1.641 2.117 104.2 27.1 18.2
2023 11 02 20 24.81 +75 13.6 1.627 2.100 103.9 27.3 18.1
2023 11 07 20 17.59 +75 00.0 1.614 2.083 103.6 27.5 18.1
2023 11 12 20 13.95 +74 48.2 1.600 2.069 103.5 27.7 18.0
2023 11 17 20 13.76 +74 40.4 1.587 2.056 103.4 27.9 18.0
2023 11 22 20 16.90 +74 37.8 1.574 2.044 103.5 28.0 18.0
2023 11 27 20 23.31 +74 41.3 1.562 2.035 103.6 28.1 17.9
2023 12 02 20 33.09 +74 51.1 1.549 2.027 103.9 28.2 17.9
2023 12 07 20 46.46 +75 06.7 1.538 2.021 104.3 28.2 17.9
2023 12 12 21 03.77 +75 27.2 1.527 2.016 104.7 28.2 17.9
2023 12 17 21 25.48 +75 50.6 1.517 2.014 105.2 28.1 17.8
2023 12 22 21 52.03 +76 14.2 1.509 2.013 105.8 28.0 17.8
2023 12 27 22 23.72 +76 33.7 1.502 2.014 106.4 27.9 17.8
2024 01 01 23 00.45 +76 44.1 1.498 2.017 106.9 27.8 17.8
2024 01 06 23 41.35 +76 39.4 1.497 2.022 107.4 27.7 17.8
2024 01 11 00 24.61 +76 14.8 1.500 2.029 107.7 27.5 17.8
2024 01 16 01 07.82 +75 26.9 1.506 2.037 108.0 27.3 17.9
2024 01 21 01 48.72 +74 15.2 1.517 2.047 108.0 27.2 17.9
2024 01 26 02 25.82 +72 41.6 1.532 2.059 107.8 27.1 17.9
2024 01 31 02 58.61 +70 49.5 1.553 2.072 107.3 27.0 18.0
2024 02 05 03 27.24 +68 43.0 1.580 2.087 106.6 26.9 18.0
2024 02 10 03 52.20 +66 26.1 1.613 2.104 105.5 26.9 18.1
2024 02 15 04 14.11 +64 02.6 1.651 2.122 104.2 26.8 18.2
2024 02 20 04 33.50 +61 35.7 1.695 2.142 102.7 26.8 18.3
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2023 CBAT
2023 October 21 (CBET 5304) Daniel W. E. Green
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