[Iaude] CBET 4832: COMET P/2008 QP20
quai at eps.harvard.edu
quai at eps.harvard.edu
Sun Aug 16 20:04:56 EDT 2020
Electronic Telegram No. 4832
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
RECOVERY OF COMET P/2008 QP_20 (LINEAR-HILL)
S. Nakano, Central Bureau, has identified recovery observations of comet
P/2008 QP_20 (cf. IAUC 8979) in astrometry published on MPEC 2020-P19; the
astrometry, which is tabulated below, was reported by S. Deen, Simi Valley,
CA, USA, from DECam images obtained with the 4.0-m reflector at Cerro Tololo.
Following a query by the Central Bureau, Deen provides additional information:
he measures a small slightly condensed coma of size about 2" (full-width-at-
half-maximum) on the g-band (first) image from 2016 Jan. 15.26 UT, with the
seeing 1".4, and notes a possible very faint, diffuse tail 15" long toward
p.a. 260 degrees; the second (r-band) image on Jan. 15 shows a moderately
condensed coma of size 1".5 (FWHM) in 1".3 seeing, noting also a faint,
broad 15" tail in p.a. 260 degrees. On the z-band images from 2016 Mar.
1.14, taken in 1".1 seeing, Deen sees the comet as very close to the stellar
size with no visible tail.
2016 UT R.A. (2000) Decl. Mag.
Jan. 15.25925 9 32 52.77 +17 38 30.6 21.4
15.26029 9 32 52.74 +17 38 31.0 21.6
Mar. 1.13752 8 50 41.89 +18 41 57.4
1.13891 8 50 41.82 +18 41 57.4 21.8
The residuals of the recovery observations above were -29" in R.A. and +17"
in Decl. with respect to the prediction in the ICQ's 2014 Comet Handbook (and
NK 2300), with the indicated correction to the time of perihelion being
Delta(T) = +0.03 day. The following linked orbital elements by Nakano are
from 477 observations spanning 2008 Aug. 25-2016 Mar. 1 (mean residual 0".6).
Epoch = 2008 Oct. 21.0 TT
T = 2008 Nov. 2.69871 TT Peri. = 72.03934
e = 0.5063110 Node = 325.15191 2000.0
q = 1.7231412 AU Incl. = 7.74979
a = 3.4903371 AU n = 0.15114821 P = 6.52 years
Epoch = 2015 May 18.0 TT
T = 2015 May 17.27592 TT Peri. = 72.35404
e = 0.5063876 Node = 324.96675 2000.0
q = 1.7233825 AU Incl. = 7.74179
a = 3.4913677 AU n = 0.15108129 P = 6.52 years
Epoch = 2022 Jan. 21.0 TT
T = 2022 Jan. 2.13736 TT Peri. = 75.54133
e = 0.4913052 Node = 322.07073 2000.0
q = 1.8062430 AU Incl. = 7.52187
a = 3.5507401 AU n = 0.14730780 P = 6.69 years
Epoch = 2028 Sept.26.0 TT
T = 2028 Sept.16.96896 TT Peri. = 75.68914
e = 0.4900286 Node = 321.98807 2000.0
q = 1.8148516 AU Incl. = 7.51303
a = 3.5587319 AU n = 0.14681187 P = 6.71 years
Epoch = 2035 June 2.0 TT
T = 2035 June 1.23314 TT Peri. = 75.59879
e = 0.4901628 Node = 321.95452 2000.0
q = 1.8148645 AU Incl. = 7.50859
a = 3.5596943 AU n = 0.14675234 P = 6.72 years
The following ephemeris by the undersigned for the next return of this comet,
from the above elements, uses photometric power-law parameters H = 14.0 and
2.5n = 15 for the pre-perihelion magnitudes, based entirely on the 2008
pre-perihelion astrometric magnitudes. There appears to be an asymmetry
between pre-perihelion and post-perihelion brightness, with H = 14.0 and
2.5n = 10 better representing the 2008-2009 post-perihelion reported
magnitudes, and these parameters are used below for post-perihelion
predicted magnitudes; however, the 2016 data reported by Deen (above) are
two magnitudes fainter than these parameters suggest.
Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag.
2021 07 05 23 09.00 -05 08.6 1.733 2.370 116.6 22.5 20.8
2021 07 15 23 13.53 -04 02.0 1.587 2.321 124.7 21.1 20.5
2021 07 25 23 15.81 -03 02.8 1.453 2.273 133.3 19.0 20.2
2021 08 04 23 15.56 -02 12.6 1.333 2.226 142.6 16.1 19.8
2021 08 14 23 12.61 -01 32.7 1.231 2.180 152.5 12.4 19.5
2021 08 24 23 07.11 -01 03.9 1.149 2.135 162.8 8.0 19.2
2021 09 03 22 59.61 -00 45.5 1.088 2.093 172.5 3.6 19.0
2021 09 13 22 51.12 -00 35.7 1.052 2.052 171.2 4.3 18.8
2021 09 23 22 43.04 -00 30.1 1.038 2.013 160.9 9.4 18.6
2021 10 03 22 36.75 -00 23.9 1.046 1.977 150.0 14.7 18.5
2021 10 13 22 33.38 -00 12.0 1.073 1.944 139.6 19.4 18.5
2021 10 23 22 33.56 +00 10.1 1.115 1.914 130.0 23.5 18.5
2021 11 02 22 37.43 +00 44.9 1.169 1.886 121.3 26.7 18.5
2021 11 12 22 44.84 +01 33.9 1.233 1.863 113.4 29.2 18.5
2021 11 22 22 55.42 +02 37.5 1.303 1.843 106.4 30.9 18.6
2021 12 02 23 08.74 +03 55.0 1.378 1.828 99.9 32.1 18.6
2021 12 12 23 24.40 +05 25.2 1.458 1.816 94.1 32.7 18.7
2021 12 22 23 42.01 +07 06.4 1.541 1.809 88.7 32.9 18.8
2022 01 01 00 01.25 +08 56.2 1.627 1.806 83.7 32.8 18.9
2022 01 11 00 21.87 +10 52.3 1.716 1.808 79.0 32.3 17.7
2022 01 21 00 43.64 +12 51.9 1.807 1.814 74.6 31.5 17.9
2022 01 31 01 06.39 +14 52.1 1.902 1.825 70.4 30.6 18.0
2022 02 10 01 29.97 +16 50.2 1.999 1.839 66.3 29.4 18.2
2022 02 20 01 54.24 +18 43.5 2.098 1.858 62.3 28.1 18.3
2022 03 02 02 19.09 +20 29.4 2.200 1.881 58.4 26.7 18.5
2022 03 12 02 44.41 +22 05.8 2.303 1.907 54.5 25.1 18.6
2022 03 22 03 10.05 +23 30.7 2.408 1.937 50.7 23.5 18.8
2022 04 01 03 35.89 +24 42.8 2.513 1.969 46.8 21.7 18.9
2022 04 11 04 01.81 +25 40.9 2.618 2.005 42.9 19.9 19.1
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2020 CBAT
2020 August 16 (CBET 4832) Daniel W. E. Green
More information about the Iaude
mailing list