[Iaude] CBET 4805: COMET 12P
quai at eps.harvard.edu
quai at eps.harvard.edu
Sat Jun 27 21:38:08 EDT 2020
Electronic Telegram No. 4805
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 12P/PONS-BROOKS
This comet (cf. CBET 4727) has been recovered on G-band CCD images taken
on June 10 and 17 (astrometry tabulated below) with the Lowell Observatory
4.3-m Discovery Telescope (+ Large Monolithic Imager) by M. M. Knight, C. E.
Holt, Q.-Z. Ye, L. M. Feaga, M. S. P. Kelley, L. Shumar, J. Sanborn, and A.
Hayslip (and measured by Ye and T. L. Farnham). Ye adds that the head of the
comet had a full-width-at-half-maximum (FWHM) size of about 1".2, which was
largely consistent with the sizes of nearby stars; on a stacked image, there
is a broad tail about 3" long pointing towards p.a. about 170-200 degrees,
implying that the comet has been active for some time (now at r = 11.9 AU).
2020 UT R.A. (2000) Decl. Mag. Observer
June 10.39794 18 04 12.24 +20 53 53.1 22.8 Knight
10.40191 18 04 12.14 +20 53 53.1 22.7 "
10.44291 18 04 11.21 +20 53 55.9 23.2 "
17.31258 18 01 46.05 +21 01 28.6 24.0 "
17.31624 18 01 45.96 +21 01 28.8 24.0 "
17.31990 18 01 45.88 +21 01 29.0 23.8 "
17.32354 18 01 45.80 +21 01 29.3 23.9 "
17.32720 18 01 45.72 +21 01 29.4 23.8 "
Regarding the linked orbit by T. Kobayashi on CBET 4727, the residuals
for the 2020 observations are off by about -2" in R.A. and about -5" in Decl.,
with the indicated correction being Delta(T) = +0.16 day. S. Nakano, Sumoto,
Japan, reports the following linked orbital elements from 1074 observations
spanning 1812 July 21-2020 June 17 and four apparitions (weighted mean
residual 1".35); see CBET 4727 for details on the 19th-century astrometry.
The associated non-gravitational parameters are A_1 = +0.06 and A_2 = -0.0270.
The comet passed 3.71 AU from Uranus on 1819 Apr. 26 and 1.62 AU from Saturn
on 1957 July 29 UT. This orbit gives T = 1385 Nov. 6.25 and 1457 Jan. 30.06
TT, with residuals of a couple degrees for C/1385 U1 and about a degree for
C/1457 A1.
Epoch = 1812 Aug. 30.0 TT
T = 1812 Sept.15.82498 TT Peri. = 199.28730
e = 0.9553351 Node = 255.63886 2000.0
q = 0.7771150 AU Incl. = 73.95648
a = 17.3988017 AU n = 0.01358079 P = 72.57 years
Epoch = 1884 Jan. 25.0 TT
T = 1884 Jan. 26.21585 TT Peri. = 199.17512
e = 0.9550459 Node = 255.77461 2000.0
q = 0.7757414 AU Incl. = 74.04054
a = 17.2563096 AU n = 0.01374935 P = 71.68 years
Epoch = 1954 May 18.0 TT
T = 1954 May 22.87787 TT Peri. = 199.02671
e = 0.9548407 Node = 255.89104 2000.0
q = 0.7736655 AU Incl. = 74.17695
a = 17.1319179 AU n = 0.01389937 P = 70.91 years
Epoch = 2024 May 10.0 TT
T = 2024 Apr. 21.00504 TT Peri. = 198.98782
e = 0.9545989 Node = 255.85602 2000.0
q = 0.7807733 AU Incl. = 74.19143
a = 17.1972223 AU n = 0.01382027 P = 71.32 years
Epoch = 2095 Aug. 26.0 TT
T = 2095 Aug. 10.86168 TT Peri. = 198.89121
e = 0.9548999 Node = 255.92846 2000.0
q = 0.7836207 AU Incl. = 74.04352
a = 17.3751293 AU n = 0.01360855 P = 72.43 years
The following ephemeris by the undersigned from the above elements uses
power-law photometric parameters H = 4.0 and 2.5n = 12 for the total
magnitudes.
Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag.
2020 05 31 18 07.69 +20 37.0 11.290 11.987 131.5 3.6 22.2
2020 07 10 17 53.70 +21 04.9 11.065 11.770 132.1 3.7 22.1
2020 08 19 17 42.81 +19 59.4 11.163 11.551 110.1 4.7 22.0
2020 09 28 17 40.62 +18 06.6 11.430 11.328 81.6 5.0 21.9
2020 11 07 17 47.72 +16 29.6 11.643 11.102 54.9 4.2 21.9
2020 12 17 18 01.02 +15 55.5 11.613 10.873 39.6 3.3 21.8
2021 01 26 18 15.64 +16 47.1 11.259 10.640 49.1 4.0 21.6
2021 03 07 18 26.19 +19 01.1 10.636 10.404 73.9 5.3 21.3
2021 04 16 18 27.76 +22 03.6 9.913 10.164 101.7 5.5 21.1
2021 05 26 18 18.08 +24 46.3 9.308 9.920 124.7 4.8 20.8
2021 07 05 18 00.88 +25 48.9 8.993 9.672 129.6 4.6 20.6
2021 08 14 17 45.81 +24 42.1 8.994 9.420 112.0 5.7 20.5
2021 09 23 17 41.21 +22 19.7 9.183 9.163 85.7 6.3 20.4
2021 11 02 17 48.68 +20 07.2 9.352 8.902 60.3 5.6 20.2
2021 12 12 18 04.78 +19 10.3 9.318 8.635 43.9 4.5 20.1
2022 01 21 18 23.98 +20 03.5 8.991 8.364 47.9 5.0 19.8
2022 03 02 18 39.94 +22 52.1 8.402 8.087 68.2 6.5 19.5
2022 04 11 18 46.04 +27 07.3 7.685 7.803 93.1 7.4 19.1
2022 05 21 18 36.93 +31 29.8 7.035 7.514 114.7 7.0 18.7
2022 06 30 18 13.92 +33 53.7 6.618 7.218 122.7 6.8 18.4
2022 08 09 17 50.09 +32 56.5 6.487 6.915 110.9 7.9 18.1
2022 09 18 17 40.46 +29 38.8 6.546 6.604 88.9 8.8 17.9
2022 10 28 17 48.98 +26 16.0 6.615 6.284 66.5 8.3 17.7
2022 12 07 18 11.31 +24 33.6 6.530 5.956 50.8 7.4 17.4
2023 01 16 18 40.84 +25 30.3 6.208 5.618 49.4 7.6 17.0
2023 02 25 19 10.55 +29 32.7 5.663 5.268 61.8 9.5 16.4
2023 04 06 19 32.17 +36 37.9 4.991 4.907 79.4 11.6 15.8
2023 05 16 19 33.78 +45 46.5 4.332 4.532 94.9 12.8 15.1
2023 06 25 18 59.14 +53 48.5 3.807 4.142 102.1 13.9 14.3
2023 08 04 17 55.68 +55 27.3 3.456 3.734 97.9 15.6 13.6
2023 09 13 17 19.54 +50 07.5 3.211 3.306 86.5 17.7 12.8
2023 10 23 17 33.16 +43 09.5 2.952 2.854 74.6 19.6 11.8
2023 12 02 18 27.92 +38 36.4 2.591 2.376 66.4 22.4 10.6
2024 01 11 20 06.46 +37 53.2 2.143 1.868 60.6 27.3 8.9
2024 02 20 22 48.66 +37 21.1 1.751 1.339 49.5 34.1 6.7
2024 03 31 02 05.10 +23 33.5 1.611 0.875 28.6 33.1 4.3
2024 05 10 04 31.52 -03 41.0 1.578 0.859 29.6 35.5 4.2
2024 06 19 07 00.36 -29 54.8 1.578 1.313 55.9 39.9 6.4
2024 07 29 10 07.56 -44 45.6 1.983 1.842 67.0 30.5 8.7
2024 09 07 12 40.00 -47 29.2 2.730 2.351 57.7 21.2 10.6
2024 10 17 14 23.45 -47 30.8 3.520 2.831 40.0 13.1 12.2
2024 11 26 15 39.65 -47 42.1 4.128 3.283 27.4 7.9 13.3
2025 01 05 16 36.60 -48 20.6 4.428 3.712 38.8 9.5 14.1
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2020 CBAT
2020 June 28 (CBET 4805) Daniel W. E. Green
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