[Iaude] CBET 4597: 20190109 : (6478) GAULT

[quai at eps.harvard.edu]

                                                  Electronic Telegram No. 4597
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


(6478) GAULT
     Further to CBET 4594, A. Hale writes that he has posted two images at
website URL http://earthriseinstitute.org/gault.html.  The upper image is an
image taken with the Canada-France-Hawaii telescope as provided by H. Weiland
to R. Berry.  The lower image was the one taken by Hale on Jan. 8.0 UT.
     Fifty 60-s unfiltered CCD exposures taken by A. Maury, J.-B. de Vanssay,
and J.-F. Soulier with a 0.4-m f/5 Ritchey-Chretien reflector at San Pedro de
Atacama, Chile, on Jan. 8.32 UT show a 15" tail and a tail about 4' long in
p.a. about 300 degrees; Soulier notes that the red magnitude of the object's
head was about 17.4 as measured in a photometric aperture of radius 6".7.
Soulier adds that he obtained seventy-five 60-s unfiltered exposures with a
0.20-m f/4 Newtonian reflector at Dauban, France, on Jan. 9.15-9.20 that show
a coma about 19" across and a tail about 3'.5 long in p.a. about 310 deg; the
red mag was 17.5-17.6 as measured in an aperture of radius 6".6.
     T. Yusa, Osaki, Japan, reports that eight stacked 90-s CCD exposures
taken on Jan. 8.7 UT with an iTelescope 0.50-m f/6.8 astrograph at Siding
Spring, NSW, show the object's head to be completely stellar in appearance
and of mag 17.8 (luminance filter, compared to V-band magnitudes of stars in
the USNO-A2.0 catalogue) but with a straight 180" tail toward p.a. 292 deg;
Yusa has posted an image at the following website URL:
https://sites.google.com/view/cometobserve/comets/mp6478_20190109.
     K. Kadota, Ageo, Japan, found a stellar head of mag 17.4 with a straight,
narrow tail 2'.7 long in p.a. 293 deg on CCD exposures taken on Jan. 8.7 UT
with a 0.25-m f/5 reflector.
     M. Micheli writes that CCD images taken by P. Ruiz with a 1.0-m f/4.4
reflector at the European Space Agency's Optical Ground Station at Tenerife
on Jan. 9.1 UT (measured by Micheli, D. Koschny, A. Knoefel, M. Busch, and
E. Schwab) show a very thin tail 4' long at p.a. 291.5 degrees; the magnitude
of the object's head was measured as 17.6.
     L. Buzzi, Varese, Italy, writes that stacked CCD images taken with a
0.84-m f/3.5 reflector in good transparency but mediocre seeing on Jan. 9.2
UT show a stellar head with a dust trail at least 135" long in p.a. 292 deg;
the magnitude was measured as 17.7.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2019 CBAT
2019 January 9                   (CBET 4597)              Daniel W. E. Green