[Iaude] CBET 4707: COMET P/2019 W1
quai at eps.harvard.edu
quai at eps.harvard.edu
Fri Dec 20 23:40:27 EST 2019
Electronic Telegram No. 4707
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/2019 W1 (PANSTARRS)
R. Weryk, Institute for Astronomy, University of Hawaii, reports the
discovery of another comet in images obtained in poor seeing (about 1".8) on
Nov. 29 UT with the Pan-STARRS2 1.8-m Ritchey-Chretien reflector at Haleakala
(discovery observations tabulated below). The comet was described as very
diffuse with a diameter of 2".5 and as having a broad tail 12" long in p.a.
260 degrees.
2019 UT R.A. (2000) Decl. Mag.
Nov. 29.54123 6 36 55.60 +48 33 37.9 20.5
29.55366 6 36 55.06 +48 33 43.7 20.0
29.56608 6 36 54.56 +48 33 49.4 20.2
29.57854 6 36 53.96 +48 33 54.7 20.3
Weryk reports that follow-up CCD images were obtained in 1".0 seeing by R.
Wainscoat, H. Januszewski, A. Petric and himself with the 3.6-m Canada-
France-Hawaii Telescope on Mauna Kea on Dec. 3.6 UT that confirm the object
to be a diffuse comet with a coma diameter of 1".7 and a broad, 12"-long tail
in p.a. 220 and 290 degrees. Weryk also provides pre-discovery astrometry
from very faint images of the comet that he identified from exposures taken
on 2018 Aug. 8 and 21 and on 2019 Jan. 1 and 24 with the Pan-STARRS1 1.8-m
Ritchey-Chretien reflector at Haleakala, for which he measured magnitudes
22-24, adding that the images were too faint to be able to comment on the
comet's morphology.
After the object was posted on the Minor Planet Center's PCCP webpage,
other CCD astrometrists also reported on the cometary appearance. K.
Sarneczky, Konkoly Observatory, reports that three stacked 120-s unfiltered
CCD images taken with the 0.60-m Schmidt telescope at Piszkesteto, Hungary,
on Nov. 30.9 UT show a condensed coma 6" in diameter and a straight tail
about 8" long in p.a. 260 deg. R. Haver, Frasso Sabino, Italy, writes that
forty 90-s exposures taken on Dec. 1.0 with a 0.37-m f/7 Cassegrain reflector
show the comet's size to be about 1".7 larger than that of neighboring stars
(seeing 3".7). P. Birtwhistle, Great Shefford, Berkshire, England, finds
an "only moderately concentrated" coma of diameter 10" and magnitude
19.3-19.5 with a 20" tail in p.a. 250 deg, adding that the object is
"obviously cometary" in images taken with a 0.41-m f/6.3 Schmidt-Cassegrain
reflector on Dec. 2.04-2.07. Twelve stacked 120-s unfiltered images taken
by G. Favero and R. Furgoni with a 0.80-m f/4 reflector at the Osservatorio
del Celado, Castello Tesino, Italy, on Dec. 4.9 show an elongated coma and
a faint tail about 10" long in p.a. 240 deg. Twenty stacked 60-s exposures
taken remotely by H. Sato, Tokyo, Japan, with a 0.43-m f/6.8 astrograph near
Mayhill, NM, USA, on Dec. 18.2 show a weakly condensed coma 10" in diameter
with no tail; he measured mag 21.3 within a circular aperture of radius 5".7.
G. Hug, Scranton, KS, U.S.A., reports that images taken on Dec. 18.35-18.39
with a 0.56-m reflector show little central condensation, the comet appearing
"nebulous" with a faint extension extending about 25" in p.a. about 220 deg;
he gave the magnitude as 20.9-21.0.
The available astrometry appear on MPEC 2019-Y37. The following
elliptical orbital elements by S. Nakano (Sumoto, Japan) are from 71
observations spanning 2018 Aug. 8-2019 Dec. 20 (mean residual 0".54); he
notes that a search of past archival astrometry found no other observations
of this comet.
Epoch = 2019 Apr. 27.0 TT
T = 2019 May 8.09212 TT Peri. = 18.76387
e = 0.2659157 Node = 35.42842 2000.0
q = 3.3399177 AU Incl. = 23.46359
a = 4.5497739 AU n = 0.10155922 P = 9.70 years
The following ephemeris by the undersigned uses photometric power-law
parameters H = 12.0 and 2.5n = 10, which only represent the post-perihelion
magnitudes (which make the comet 2-3 magnitudes brighter than the pre-
discovery, pre-perihelion magnitudes reported by Weryk above).
Date TT R. A. (2000) Decl. Delta r Elong. Phase Mag.
2019 10 04 06 30.81 +40 54.2 3.199 3.416 93.9 17.0 19.9
2019 10 09 06 34.49 +41 31.4 3.137 3.421 97.9 16.8 19.8
2019 10 14 06 37.68 +42 09.8 3.077 3.426 102.0 16.5 19.8
2019 10 19 06 40.34 +42 49.5 3.018 3.432 106.2 16.2 19.8
2019 10 24 06 42.41 +43 30.2 2.962 3.437 110.4 15.7 19.7
2019 10 29 06 43.87 +44 12.0 2.908 3.443 114.7 15.2 19.7
2019 11 03 06 44.65 +44 54.4 2.856 3.449 119.0 14.6 19.7
2019 11 08 06 44.75 +45 37.2 2.809 3.455 123.4 13.9 19.6
2019 11 13 06 44.14 +46 20.0 2.765 3.461 127.7 13.1 19.6
2019 11 18 06 42.79 +47 02.1 2.726 3.467 132.1 12.2 19.6
2019 11 23 06 40.72 +47 43.1 2.692 3.473 136.3 11.3 19.6
2019 11 28 06 37.93 +48 22.1 2.663 3.480 140.3 10.4 19.5
2019 12 03 06 34.47 +48 58.4 2.640 3.486 144.0 9.6 19.5
2019 12 08 06 30.41 +49 31.3 2.623 3.493 147.3 8.8 19.5
2019 12 13 06 25.86 +50 00.1 2.613 3.500 150.0 8.1 19.5
2019 12 18 06 20.92 +50 24.2 2.609 3.507 151.8 7.6 19.5
2019 12 23 06 15.73 +50 43.1 2.612 3.514 152.6 7.4 19.5
2019 12 28 06 10.45 +50 56.6 2.621 3.521 152.2 7.5 19.6
2020 01 02 06 05.24 +51 04.5 2.638 3.529 150.8 7.8 19.6
2020 01 07 06 00.27 +51 07.1 2.661 3.536 148.4 8.4 19.6
2020 01 12 05 55.67 +51 04.6 2.690 3.544 145.4 9.1 19.6
2020 01 17 05 51.56 +50 57.5 2.726 3.552 141.8 9.9 19.7
2020 01 22 05 48.05 +50 46.5 2.767 3.559 138.0 10.7 19.7
2020 01 27 05 45.21 +50 32.0 2.814 3.567 133.9 11.5 19.8
2020 02 01 05 43.10 +50 14.8 2.865 3.575 129.7 12.2 19.8
2020 02 06 05 41.74 +49 55.6 2.921 3.584 125.4 13.0 19.9
2020 02 11 05 41.14 +49 34.8 2.981 3.592 121.1 13.6 19.9
2020 02 16 05 41.26 +49 13.0 3.045 3.600 116.8 14.2 20.0
2020 02 21 05 42.11 +48 50.5 3.111 3.609 112.6 14.7 20.0
2020 02 26 05 43.64 +48 27.7 3.180 3.617 108.4 15.0 20.1
2020 03 02 05 45.82 +48 04.9 3.251 3.626 104.3 15.4 20.2
2020 03 07 05 48.61 +47 42.1 3.324 3.635 100.3 15.6 20.2
2020 03 12 05 51.95 +47 19.7 3.398 3.643 96.3 15.7 20.3
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2019 CBAT
2019 December 21 (CBET 4707) Daniel W. E. Green
More information about the Iaude
mailing list