[Iaude] CBET 5422: COMET P/2024 N5 = P/2012 US_27
quai at eps.harvard.edu
quai at eps.harvard.edu
Sat Jul 27 01:55:39 EDT 2024
Electronic Telegram No. 5422
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 P/2024 N5 = P/2012 US_27 (SIDING SPRING)
Martin Masek reports the recovery of comet P/2012 US27 (cf. CBET 3310)
on CCD images taken on July 5 and 6 UT at the Pierre Auger Observatory at
Malarguee, Mendoza, Argentina, using a 0.3-m f/6.8 reflector ("Fotometric
Robotic Atmospheric Monitor"). The object appears essentially stellar, but
Masek measured the head of the comet to have a size of 5".6 (full-width-at-
half-maximum) in 4".7-5".2 seeing in the July 5 images. The astrometry is
tabulated below.
2024 UT R.A. (2000) Decl. Mag. Observer
July 5.35240 2 54 48.76 -11 16 30.1 19.1 Masek
5.35959 2 54 49.50 -11 16 24.8 19.3 "
5.38126 2 54 51.67 -11 16 08.0 19.2 "
5.40239 2 54 53.78 -11 15 51.2 19.2 "
5.40960 2 54 54.52 -11 15 45.5 19.2 "
6.37942 2 56 32.90 -11 03 15.9 19.6 "
6.41497 2 56 36.45 -11 02 48.3 19.5 "
11.39605 3 04 56.93 - 9 58 33.4 19.2 "
11.41760 3 04 59.07 - 9 58 16.9 19.2 "
The object was posted on the Minor Planet Center's NEOCP webpage, and
additional astrometry appears on MPEC 2024-O57. Twelve stacked 60-s CCD
exposures taken remotely by H. Sato (Bunkyo-ku, Tokyo, Japan) on 2024 July
25.4 UT with a "Deep Sky Chile" 0.51-m f/6.8 astrograph located in Rio
Hurtado, Chile, shows a strongly condensed coma 5" in diameter and no tail;
the magnitude was 18.5 as measured within a circular aperture of radius 2".8.
S. Deen (Simi Valley, CA, USA), writes that he has identified apparent
images of this comet in publicly available images obtained with the 3.5-m
telescope at Apache Point in the course of the Sloan Digital Sky Survey on
2002 Feb. 13.4 UT; Deen notes an essentially stellar nuclear condensation of
size 0".9 (FWHM) but with a clearly detached tail separated from the head by
5".5 and with a length of about 50" in p.a. 304 degrees. Deen's astrometry
is provided below.
2002 UT R.A. (2000) Decl. Mag.
Feb. 13.44440 12 17 10.00 +58 57 09.6 21.5
13.44523 12 17 09.91 +58 57 10.0 21.5
13.44688 12 17 09.78 +58 57 10.3 20.7
13.44771 12 17 09.74 +58 57 10.7 22.1
The residuals for the recovery observations were +7'.7 in R.A. and +13'.1 in
Decl. from the prediction in NK 2665 (and ICQ Comet Handbook 2023), with a
corresponding correction of Delta(T) = -0.67 day. The 2002 observations were
only 4" off the predicted position from an orbit covering only the 2013 and
2024 apparitions. The following linked orbital elements by S. Nakano (Central
Bureau) are from 339 observations spanning 2002 Feb. 13-2024 July 25 (mean
residual 0".5). There are no close approaches to major planets.
Epoch = 1989 July 13.0 TT
T = 1989 July 3.78184 TT Peri. = 2.01673
e = 0.6480828 Node = 49.21843 2000.0
q = 1.8394203 AU Incl. = 39.07255
a = 5.2268552 AU n = 0.08247900 P = 11.95 years
Epoch = 2001 May 11.0 TT
T = 2001 May 6.76063 TT Peri. = 1.65553
e = 0.6485331 Node = 49.20961 2000.0
q = 1.8283189 AU Incl. = 39.19627
a = 5.2019655 AU n = 0.08307166 P = 11.86 years
Epoch = 2013 Jan. 28.0 TT
T = 2013 Feb. 8.55790 TT Peri. = 1.27008
e = 0.6485996 Node = 49.20691 2000.0
q = 1.8208299 AU Incl. = 39.29238
a = 5.1816391 AU n = 0.08356094 P = 11.80 years
Epoch = 2024 Oct. 17.0 TT
T = 2024 Oct. 20.65464 TT Peri. = 0.86597
e = 0.6486278 Node = 49.21139 2000.0
q = 1.8149783 AU Incl. = 39.36973
a = 5.1654008 AU n = 0.08395528 P = 11.74 years
Epoch = 2036 May 27.0 TT
T = 2036 June 14.70921 TT Peri. = 0.47686
e = 0.6488411 Node = 49.22199 2000.0
q = 1.8091809 AU Incl. = 39.43187
a = 5.1520295 AU n = 0.08428234 P = 11.69 years
Epoch = 2048 Jan. 5.0 TT
T = 2048 Jan. 21.39838 TT Peri. = 0.14974
e = 0.6512972 Node = 49.20698 2000.0
q = 1.7909369 AU Incl. = 39.53111
a = 5.1359973 AU n = 0.08467728 P = 11.64 years
The following ephemeris by the undersigned from the above orbital elements
uses photometric power-law parameters H = 14.0 and 2.5n = 10 for the
magnitudes. The 2002 and 2024 apparitions have observed magnitudes that
are both about 1.5 mag fainter than those at the 2013 apparition (where
H_10 was around 12.5).
Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag.
2024 06 19 02 26.60 -14 47.8 2.465 2.196 62.9 24.3 19.4
2024 06 29 02 43.97 -12 38.5 2.339 2.144 66.4 25.7 19.2
2024 07 09 03 00.95 -10 29.5 2.211 2.094 70.0 27.1 18.9
2024 07 19 03 17.43 -08 20.0 2.081 2.047 73.9 28.5 18.7
2024 07 29 03 33.30 -06 08.2 1.951 2.004 78.0 29.7 18.5
2024 08 08 03 48.43 -03 52.2 1.820 1.964 82.4 30.8 18.2
2024 08 18 04 02.60 -01 28.5 1.690 1.928 87.3 31.6 18.0
2024 08 28 04 15.59 +01 07.2 1.560 1.896 92.6 32.2 17.7
2024 09 07 04 27.07 +04 00.5 1.433 1.869 98.5 32.2 17.5
2024 09 17 04 36.58 +07 18.9 1.310 1.848 105.1 31.7 17.3
2024 09 27 04 43.59 +11 11.2 1.194 1.831 112.7 30.3 17.0
2024 10 07 04 47.31 +15 46.4 1.089 1.820 121.2 28.0 16.8
2024 10 17 04 46.81 +21 10.9 1.000 1.815 130.8 24.6 16.6
2024 10 27 04 41.05 +27 22.2 0.933 1.816 141.0 20.2 16.4
2024 11 06 04 29.03 +34 00.8 0.893 1.823 150.5 15.5 16.4
2024 11 16 04 10.66 +40 28.0 0.886 1.835 156.2 12.6 16.4
2024 11 26 03 47.48 +45 59.0 0.912 1.853 154.6 13.2 16.5
2024 12 06 03 23.09 +50 05.2 0.969 1.876 147.5 16.4 16.7
2024 12 16 03 02.01 +52 48.2 1.050 1.904 138.7 19.9 16.9
2024 12 26 02 47.52 +54 29.7 1.151 1.937 130.1 22.8 17.2
2025 01 05 02 40.89 +55 34.3 1.266 1.974 122.2 24.9 17.5
2025 01 15 02 41.83 +56 21.0 1.390 2.015 115.1 26.2 17.8
2025 01 25 02 49.38 +56 59.9 1.522 2.060 108.6 26.9 18.0
2025 02 04 03 02.52 +57 35.1 1.658 2.107 102.7 27.2 18.3
2025 02 14 03 20.32 +58 07.5 1.797 2.158 97.3 27.0 18.6
2025 02 24 03 41.97 +58 35.3 1.939 2.211 92.2 26.6 18.9
2025 03 06 04 06.79 +58 56.1 2.082 2.266 87.4 25.9 19.1
2025 03 16 04 34.07 +59 07.1 2.225 2.323 82.9 25.1 19.4
2025 03 26 05 03.11 +59 05.9 2.369 2.381 78.6 24.2 19.6
2025 04 05 05 33.23 +58 50.7 2.513 2.441 74.3 23.2 19.9
2025 04 15 06 03.74 +58 20.7 2.656 2.502 70.3 22.2 20.1
2025 04 25 06 34.03 +57 35.7 2.798 2.564 66.3 21.0 20.3
2025 05 05 07 03.60 +56 36.5 2.939 2.627 62.3 19.9 20.5
2025 05 15 07 32.09 +55 24.6 3.077 2.690 58.5 18.7 20.7
2025 05 25 07 59.26 +54 01.8 3.213 2.754 54.7 17.5 20.9
2025 06 04 08 25.03 +52 29.9 3.345 2.818 50.9 16.2 21.1
2025 06 14 08 49.35 +50 51.3 3.472 2.882 47.3 15.0 21.3
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2024 CBAT
2024 July 27 (CBET 5422) Daniel W. E. Green
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