Electronic Telegram No. 5554
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 P/2025 F3 = P/2018 L1 = P/2011 F2
T. Prystavski (Lviv, Ukraine) reports the recovery of this comet (cf.
CBET 4521) on CCD images obtained on Apr. 9 and on subsequent dates with a
"Deep Sky Chile" 0.51-m f/6.8 "corrected Dall-Kirkham" telescope located at
Rio Hurtado, Chile (astrometry tabulated below). On Apr. 9.35 UT, when the
comet was 6'.5 from the expected position of the comet (from an orbit based
on the 2018 apparition), his exposures showed a 0'.1 tail in p.a. 44 degrees.
On May 5.21, he found a 0'.1 tail in p.a. 39 degrees. On May 7.30, there
was a 0'.1 tail in p.a. 21 degrees.
2025 UT R.A. (2000) Decl. Mag. Observer
Apr. 9.34111 13 50 46.27 -27 08 51.8 20.9 Prystavski
9.35106 13 50 45.85 -27 08 49.8 "
May 5.21034 13 29 55.83 -24 38 22.0 19.9 "
5.21476 13 29 55.63 -24 38 19.9 "
7.30124 13 28 24.02 -24 21 08.2 19.7 "
7.30421 13 28 23.89 -24 21 06.4 "
Sixteen stacked 60-s CCD exposures taken remotely on Apr. 19.45-19.46 UT by
Hidetaka Sato (Bunkyo-ku, Tokyo, Japan) using a 0.51-m f/6.8 astrograph
located at Siding Spring, NSW, Australia, show a strongly condensed coma 6" in
diameter with no tail; the magnitude was 20.3 as measured within a circular
aperture of radius 3".2.
2025 UT R.A. (2000) Decl. Mag. Observer
Apr. 19.44984 13 42 46.79 -26 26 47.1 Sato
19.45666 13 42 46.47 -26 26 45.0 20.3 "
Twenty-five stacked 60-s CCD exposures taken by T. Ikemura with a 0.38-m f/4.2
reflector at Shinshiro, Japan (and measured by Hirohisa Sato) on May 2.6 UT
show a weakly condensed coma about 5" in diameter. Thirty-one stacked 60-s
exposures taken on May 4.5 in poor transparency show a weakly condensed coma
about 6" in diameter.
2025 UT R.A. (2000) Decl. Mag. Observer
May 2.63120 13 31 54.13 -24 59 00.2 Ikemura
2.64058 13 31 53.70 -24 58 55.7 19.9 "
4.52041 13 30 27.19 -24 44 02.2 "
4.53315 13 30 26.57 -24 43 56.0 19.6 "
T. Kobayashi, Oizumi, Gunma-ken, Japan, found identifications with this comet
from five preliminarily-designated objects in the Minor Planet Center's
"isolated tracklet file" (which is accessible publicly). The following
obsesrvations from the 8.2-m Subaru Telescope at Mauna Kea do not appear on
MPEC 2025-J73. Observations from 2025 Mar. 31.4 UT obtained with the
Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala were also in the
ITF (which the MPC inadvertently used to assign a 2025 "F" designation to
this recovery).
2017 UT R.A. (2000) Decl. Mag.
Jan. 21.57598 9 59 19.26 + 0 32 25.1 25.0
21.59214 9 59 18.73 + 0 32 25.5 24.2
21.59481 9 59 18.62 + 0 32 25.8 24.5
21.61096 9 59 18.08 + 0 32 26.5 24.5
26.55620 9 56 27.43 + 0 37 09.5 24.1
26.58570 9 56 26.37 + 0 37 11.7 24.2
26.61530 9 56 25.26 + 0 37 13.5 23.5
The MPC also missed the following Pan-STARRS1 observations from the ITF:
2011 UT R.A. (2000) Decl. Mag.
June 17.25792 12 32 13.17 -15 02 40.8 18.9
The residuals of the recovery observations on 2025 Apr. 9 were +58" in R.A.
and -18" in Decl. from the prediction in NK 3713 (and in the ICQ's 2025 Comet
Handbook), with a corresponding correction of Delta(T) = -0.04 day. The
following linked orbital elements by S. Nakano (Central Bureau) are from 107
observations spanning 2011 Mar. 26-2025 May 5 (mean residual 0".4), with
corresponding non-gravitational parameters A1 = +0.20 +/- 0.07, A2 = -0.0609
+/- 0.0006. The comet passed 1.07 AU from Jupiter on 2002 Aug. 31, and it
will pass 0.52 AU from Jupiter on 2048 Nov. 27 UT.
Epoch = 1997 Dec. 18.0 TT
T = 1997 Dec. 12.57384 TT Peri. = 14.63754
e = 0.4676964 Node = 271.01253 2000.0
q = 1.9773020 AU Incl. = 10.90463
a = 3.7146135 AU n = 0.13766820 P = 7.16 years
Epoch = 2004 Dec. 21.0 TT
T = 2005 Jan. 5.78237 TT Peri. = 17.49651
e = 0.4882941 Node = 268.86478 2000.0
q = 1.8550658 AU Incl. = 10.63631
a = 3.6252577 AU n = 0.14278932 P = 6.90 years
Epoch = 2011 Dec. 25.0 TT
T = 2011 Dec. 5.97624 TT Peri. = 17.67755
e = 0.4879289 Node = 268.77142 2000.0
q = 1.8564146 AU Incl. = 10.63127
a = 3.6253067 AU n = 0.14278643 P = 6.90 years
Epoch = 2018 Nov. 18.0 TT
T = 2018 Nov. 12.52908 TT Peri. = 17.89175
e = 0.4830732 Node = 268.62697 2000.0
q = 1.8856355 AU Incl. = 10.59472
a = 3.6477807 AU n = 0.14146890 P = 6.97 years
Epoch = 2025 Nov. 21.0 TT
T = 2025 Nov. 5.54496 TT Peri. = 17.94197
e = 0.4813131 Node = 268.58181 2000.0
q = 1.8973693 AU Incl. = 10.57475
a = 3.6580247 AU n = 0.14087507 P = 7.00 years
Epoch = 2032 Oct. 15.0 TT
T = 2032 Oct. 28.84320 TT Peri. = 17.86092
e = 0.4830981 Node = 268.58521 2000.0
q = 1.8874248 AU Incl. = 10.59015
a = 3.6514179 AU n = 0.14125758 P = 6.98 years
Epoch = 2039 Oct. 19.0 TT
T = 2039 Oct. 11.96939 TT Peri. = 17.98386
e = 0.4850579 Node = 268.45705 2000.0
q = 1.8733049 AU Incl. = 10.58165
a = 3.6378945 AU n = 0.14204597 P = 6.94 years
The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 15.0 and 2.5n = 10, which
indicates that the comet is about 1 mag fainter than at the 2011 and
2018 apparitions.
Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag.
2025 05 05 13 30.09 -24 40.1 1.458 2.430 159.9 8.2 19.7
2025 05 15 13 23.49 -23 14.9 1.449 2.383 150.9 11.9 19.6
2025 05 25 13 19.22 -21 47.6 1.462 2.338 141.1 15.8 19.5
2025 06 04 13 17.86 -20 27.1 1.493 2.294 131.4 19.4 19.5
2025 06 14 13 19.63 -19 20.0 1.539 2.251 122.2 22.4 19.5
2025 06 24 13 24.46 -18 29.8 1.595 2.209 113.7 24.9 19.5
2025 07 04 13 32.17 -17 57.7 1.659 2.169 105.8 26.8 19.5
2025 07 14 13 42.50 -17 42.8 1.727 2.131 98.6 28.1 19.5
2025 07 24 13 55.17 -17 43.2 1.798 2.095 92.0 29.0 19.5
2025 08 03 14 09.96 -17 56.3 1.870 2.062 85.8 29.4 19.5
2025 08 13 14 26.65 -18 19.0 1.942 2.031 80.1 29.4 19.5
2025 08 23 14 45.04 -18 48.2 2.013 2.002 74.8 29.2 19.5
2025 09 02 15 04.99 -19 20.9 2.084 1.977 69.8 28.6 19.6
2025 09 12 15 26.34 -19 53.8 2.152 1.955 65.1 27.8 19.6
2025 09 22 15 48.96 -20 23.9 2.219 1.936 60.6 26.9 19.6
2025 10 02 16 12.69 -20 48.3 2.285 1.921 56.3 25.7 19.6
2025 10 12 16 37.37 -21 04.3 2.350 1.909 52.2 24.4 19.7
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2025 CBAT
2025 May 10 (CBET 5554) Daniel W. E. Green