Electronic Telegram No. 5520
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/2024 L4 = P/2014 N4 = P/2017 B6 (RANKIN)
S. Deen (Simi Valley, CA, USA) reports that he has found pre-discovery
observations of this comet (cf. CBET 5409) at earlier apparitions in 2004,
2014, and 2016-2017 from publicly available observations obtained with the
3.6-m Canada-France-Hawaii Telescope at Mauna Kea (2004 and 2014), the
Pan-STARRS1 1.8-m reflector at Haleakala (2014), the earth-orbiting satellite
Wide-field Infrared Survey Explorer (2014), and the 8.3-m Subaru telescope at
Mauna Kea (2017). The appearance in all the images is apparently asteroidal.
The CFHT observations as measured by Deen are tabulated below:
2004 UT R.A. (2000) Decl. Mag.
Aug. 19.34855 21 10 56.62 -16 19 10.1 23.0
19.37564 21 10 54.24 -16 19 29.7 23.2
19.40661 21 10 51.49 -16 19 52.1 23.0
2014 UT R.A. (2000) Decl. Mag.
July 18.44494 21 56 07.51 - 7 25 14.6 22.0
The Pan-STARRS1 measured by Deen are tabulated below:
2014 UT R.A. (2000) Decl. Mag.
Jan. 20.32276 3 19 23.62 + 2 07 51.1
20.33463 3 19 22.55 + 2 07 58.0
July 4.57672 22 21 17.22 - 2 49 10.1 21.6
4.59156 22 21 15.74 - 2 49 26.7 21.5
4.59898 22 21 15.01 - 2 49 34.8 21.5
The WISE observation measured by Deen is as follows:
2014 UT R.A. (2000) Decl.
Jan. 31.64423 3 06 20.63 + 4 18 35.8
The Subaru observations measured by Deen are as follows:
2016 UT R.A. (2000) Decl.
Dec. 23.29537 2 09 13.11 - 0 55 49.2
2017 UT R.A. (2000) Decl.
Jan. 21.22568 2 06 45.98 + 1 10 43.6
21.29398 2 06 47.13 + 1 11 09.0
21.30752 2 06 47.39 + 1 11 14.3
23.26041 2 07 26.63 + 1 23 43.1
23.27766 2 07 26.96 + 1 23 50.0
23.29491 2 07 27.34 + 1 23 56.7
26.23060 2 08 37.17 + 1 43 26.4
26.26757 2 08 38.07 + 1 43 41.7
26.30024 2 08 38.88 + 1 43 54.9
Deen also identified observations of the comet at mag 21.0 obtained on 2024
Mar. 22.1 UT with the Mt. Lemmon 1.5-m reflector. He adds that (apparently
unpublished) observations obtained in early July 2024 with the 4.3-m Lowell
Discovery Telescope by Q.-z. Ye show no activity whatsoever. Deen notes that
P/2024 L4 has the lowest semimajor axis and aphelion distance of any known
comet (including 2P/Encke).
CCD images obtained remotely by H. Sato (Bunkyo-ku, Tokyo, Japan) using a
0.51-m f/6.8 astrograph located at Rio Hurtado, Chile, on 2024 July 29.2 UT
showed only a stellar appearance; the magnitude was 21.0 as measured within a
circular aperture of radius 2".2.
The following linked orbital elements by S. Nakano (Central Bureau) are
from 98 observations spanning 2004 Aug. 19, 2014 Jan. 20-July 18, 2016 Dec.
23-2017 Jan. 26, and 2024 Mar. 22-July 29 (mean residual 0".3). Compared to a
recent unpublished orbit using only the 2024 observations, the comet was 0.66
deg off that orbit in 2004, 0.28 deg off that orbit in 2014, and 0.05 deg off
that orbit in 2017. The comet passed 0.011 AU and 0.079 AU from Venus on 1997
July 4 and 2020 Dec. 10 UT, respectively.
Epoch = 2000 Dec. 2.0 TT
T = 2000 Nov. 26.28865 TT Peri. = 52.58018
e = 0.6943818 Node = 140.79244 2000.0
q = 0.6828069 AU Incl. = 10.14054
a = 2.2341828 AU n = 0.29513860 P = 3.34 years
Epoch = 2004 Mar. 16.0 TT
T = 2004 Mar. 29.50115 TT Peri. = 52.54933
e = 0.6949302 Node = 140.80218 2000.0
q = 0.6814459 AU Incl. = 10.14371
a = 2.2337381 AU n = 0.29522675 P = 3.34 years
Epoch = 2007 Aug. 8.0 TT
T = 2007 Aug. 1.29034 TT Peri. = 52.61855
e = 0.6946901 Node = 140.75940 2000.0
q = 0.6819417 AU Incl. = 10.13921
a = 2.2336052 AU n = 0.29525309 P = 3.34 years
Epoch = 2010 Nov. 20.0 TT
T = 2010 Dec. 1.68811 TT Peri. = 52.57681
e = 0.6950357 Node = 140.75869 2000.0
q = 0.6810438 AU Incl. = 10.14109
a = 2.2331920 AU n = 0.29533503 P = 3.34 years
Epoch = 2014 Apr. 13.0 TT
T = 2014 Apr. 4.02342 TT Peri. = 52.64506
e = 0.6939088 Node = 140.65818 2000.0
q = 0.6842515 AU Incl. = 10.12753
a = 2.2354498 AU n = 0.29488772 P = 3.34 years
Epoch = 2017 July 26.0 TT
T = 2017 Aug. 6.88773 TT Peri. = 52.68695
e = 0.6942423 Node = 140.63774 2000.0
q = 0.6832753 AU Incl. = 10.12736
a = 2.2346955 AU n = 0.29503703 P = 3.34 years
Epoch = 2020 Dec. 17.0 TT
T = 2020 Dec. 9.40592 TT Peri. = 52.72595
e = 0.6938478 Node = 140.58702 2000.0
q = 0.6847970 AU Incl. = 10.12089
a = 2.2367862 AU n = 0.29462348 P = 3.34 years
Epoch = 2024 Mar. 31.0 TT
T = 2024 Apr. 14.29453 TT Peri. = 53.71457
e = 0.6983898 Node = 139.78002 2000.0
q = 0.6722263 AU Incl. = 10.04547
a = 2.2287917 AU n = 0.29621010 P = 3.33 years
Epoch = 2027 Aug. 23.0 TT
T = 2027 Aug. 11.86739 TT Peri. = 53.68696
e = 0.6988550 Node = 139.78533 2000.0
q = 0.6708948 AU Incl. = 10.04802
a = 2.2278132 AU n = 0.29640526 P = 3.32 years
Epoch = 2030 Dec. 5.0 TT
T = 2030 Dec. 9.06322 TT Peri. = 53.77209
e = 0.6986553 Node = 139.73365 2000.0
q = 0.6713718 AU Incl. = 10.04296
a = 2.2279199 AU n = 0.29638397 P = 3.32 years
Epoch = 2034 Mar. 19.0 TT
T = 2034 Apr. 6.11073 TT Peri. = 53.73218
e = 0.6985880 Node = 139.72826 2000.0
q = 0.6716583 AU Incl. = 10.04308
a = 2.2283731 AU n = 0.29629356 P = 3.33 years
Epoch = 2037 Aug. 10.0 TT
T = 2037 Aug. 4.73933 TT Peri. = 53.99054
e = 0.6964231 Node = 139.47087 2000.0
q = 0.6776344 AU Incl. = 10.01064
a = 2.2321673 AU n = 0.29553844 P = 3.34 years
Epoch = 2040 Nov. 22.0 TT
T = 2040 Dec. 5.01502 TT Peri. = 54.02147
e = 0.6969406 Node = 139.45889 2000.0
q = 0.6763166 AU Incl. = 10.01137
a = 2.2316303 AU n = 0.29564511 P = 3.33 years
Epoch = 2044 Apr. 15.0 TT
T = 2044 Apr. 6.30015 TT Peri. = 54.07829
e = 0.6964164 Node = 139.41312 2000.0
q = 0.6777440 AU Incl. = 10.00608
a = 2.2324788 AU n = 0.29547658 P = 3.34 years
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2025 CBAT
2025 March 11 (CBET 5520) Daniel W. E. Green