[Iaude] CBET 4793: COMET 246P/NEAT

quai at eps.harvard.edu quai at eps.harvard.edu
Tue Jun 9 16:21:26 EDT 2020


                                                  Electronic Telegram No. 4793
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 246P/NEAT
     M. Jaeger, Vienna, Austria, reports that he has detected an unsually
long, thin dust tail emanating from the coma of comet 246P on stacked 100-s
CCD images taken with a Celestron 28-cm Rowe-Ackermann Schmidt Astrograph on
Apr. 15.95, Apr. 25.93, May 12.89, and May 17.94 UT.  On the Apr. 15 (nineteen
stacked exposures) and Apr. 25 (twenty-nine stacked exposures) images, the
tail was measured to be 100' long in p.a. 297 degrees, with a 10' gap near
the head of the comet and with the tail being brightest at 30'-50' from the
coma; the first 3'.5 of tail was in p.a. 280 deg, prior to the gap.  On May
17, twenty-three stacked 100-s exposures show a tail longer than 2.2 degrees
(going outside the field-of-view) in p.a. 293 degrees.
     Total-magnitude and coma-diameter estimates of comet 246P (visual
unless noted otherwise):  Feb. 23.62, 15.4, -- (K. Kadota, Ageo, Japan,
0.25-m reflector + CCD); 29.77, 15.3, -- (Kadota); Apr. 4.59, 14.7, --
(Kadota); 19.43, 14.8, 0'.6 (C. Wyatt, Walcha, NSW, Australia, 0.40-m
reflector); 22.43, 14.7, 0'.9 (Wyatt); 24.43, 15.0, 0'.4 (Wyatt); May 11.46,
14.5, 0'.5 (P. Camilleri, Katherine, NT, Australia, 0.40-m reflector); 13.51,
14.3, 0'.6 (Camilleri); 14.27, 15.2, 0'.6 (C. S. Morris, Fillmore, CA, U.S.A.,
41-cm reflector + CCD); 16.33, 15.3, 0'.6 (Morris); 17.20, 15.4, 0'.48
(Morris); 17.39, 14.6, 0'.5 (Wyatt, 25-cm reflector); 21.31, 15.2, 0'.7
(Morris); 21.88, 13.5, 0'.4 (W. Hasubick, Buchloe, Germany, 44-cm reflector);
24.47, 14.2, 0'.8 (Camilleri).
     The comet's brightness is close to the predictions (magnitude = 7.5 +
5 log Delta + 10 log r) in the ICQ's 2020 Comet Handbook.  CCD observers are
encouraged to follow the comet's long tail as long as possible, though
wide-field Schmidt telescopes in dark-sky locations would appear to be the
best instruments for success.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2020 CBAT
2020 June 9                      (CBET 4793)              Daniel W. E. Green



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