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IAUC 8903: 8P; P/2006 W4 = P/1993 D1; Var STAR IN Ser

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                                                  Circular No. 8903
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
URL http://www.cfa.harvard.edu/iau/cbat.html  ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)

     D. Schleicher, Lowell Observatory; and L. Woodney, California
State University, San Bernardino, write that they obtained CN
narrowband imaging of comet 8P on Dec. 14 using the Hall 1.1-m
telescope at Lowell Observatory.  Following the removal of a mean
radial profile, a series of three successive spiral arcs are seen,
approximately centered in the sunward direction and extending more
than 180 degrees.  Both the spacing and the outward motion of the
arcs during a 4-hr interval imply a rotation period of 4.9-5.0 hr,
assuming that a single jet is responsible for all of the arcs.  The
projected CN gas velocity towards the position angle of the sun is
about 1.1 km/s.
     Schleicher adds that he obtained fourteen sets of narrowband
photometry of comet 8P on Dec. 3, 4, and 5 (when r = 1.31-1.29 AU)
using the Hall 1.1-m telescope at Lowell Observatory, resulting in
the following averaged production rates:  log Q(OH) = 27.80;
equivalent log Q(water; vectorial) = 27.88; log Q(NH) = 25.64; log
Q(CN) = 25.22; log Q(C_2) = 25.39; log Q(C_3) = 24.82; log Af(rho)
(526.0 nm) = 1.5 (cf. IAUC 7342).  Dust Af(rho) exhibits a strong
increasing trend with decreasing aperture size that is due, at
least in part, to a non-negligible nucleus signal.
     Total visual magnitude estimates by J. J. Gonzalez, Leon,
Spain:  Nov. 3.85 UT, 12.1 (0.20-m reflector); 9.92, 11.3 (25x100
binoculars); 13.85, 10.5; 27.79, 9.3; Dec. 5.01, 8.6 (10x50
binoculars); 11.79, 7.6.

COMET P/2006 W4 = P/1993 D1 (HILL)
     Corrigendum.  Regarding the four astrometric positions
published on IAUC 8902, the Feb. 26 data are from 1993, and the
Apr. 5 observations are from 1994.

     E. O. Waagen, AAVSO, and H. Yamaoka, Kyushu University, note
that the variable star reported on IAUC 8898 appears to be a very
bright IRAS source (IRAS 18066-0722).  Yamaoka adds that it also
appears to be catalogued by the 2MASS project, and Waagen adds that
the variable apparently is listed by the ASAS3 project as a
variable varying from V = 13.7 to [15 with a light curve that is
suggestive of a Mira-type variable with maximum around Dec. 5.
Yamaoka also reports that a low-resolution spectrum was taken by
K. Kinugasa and O. Hashimoto, Gunma Astronomical Observatory (GAO),
on Nov. 24.35 UT with the GAO 1.5-m telescope, showing that this
object is a very red star -- likely a Mira-type variable.

                      (C) Copyright 2007 CBAT
2007 December 14               (8903)            Daniel W. E. Green

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