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IAUC 4904: HAWKINS V1; 1989r

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                                               Circular No. 4904
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM     EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET    MARSDEN or GREEN@CFAPS2.SPAN


HAWKINS V1
     M. Cropper, Mullard Space Science Laboratory; J. Bailey,
Joint Astronomy Centre, Hilo; D. Wickramasinghe, Australian
National University; and L. Ferrario, Leicester University,
report: "Polarimetry of the AM-Her candidate Hawkins V1 (Tuohy et
al. 1988, Ap.J. 328, L59; R.A. = 21h34m45s.2, Decl. = -43 55'46",
equinox 1950.0) with the new Faint Object Polarimeter on the
Anglo-Australian Telescope on the nights of Oct. 27 and 29 reveals
that this object is polarized.  We therefore confirm that Hawkins
V1 is an AM-Her system.  The circular polarizations varied between
-2 and +8 percent in a broad red band and -4 and +15 percent in a
broad blue band.  The system varied between V = 18.5 and 19.5,
which is a magnitude fainter than that reported by Tuohy et al.
At this brightness, the blue and red lightcurves appear similar,
so the prominent blue peak defining phase zero in the Tuohy et al.
observations is substantially reduced in amplitude."


COMET OKAZAKI-LEVY-RUDENKO (1989r)
     D. K. Lynch and R. W. Russell, Space Sciences Laboratory, The
Aerospace Corporation, write:  "We obtained infrared circular-
variable-filter-wheel spectroscopy and filter photometry of the
comet during Nov. 5-8 using the NASA Infrared Telescope Facility
with a 9".5 aperture.  The comet shows a strong, structureless 10-
micron silicate emission feature extending about 20 percent above
the continuum.  A color temperature derived from the L, M, and 7.8-
micron magnitudes was 380 K, approximately 10 percent above the
equilibrium temperature of 345 K.  This, in concert with the existence
of silicate emission, suggests that the dust grains were optically
thin at these wavelengths.  Between Nov. 5 and 8, the 10-micron
brightness increased monotonically by roughly a factor of 2.  Magnitudes
on Nov. 8.8 UT:  L = 6.7, M = 4.4, and [10.3 microns] = 0.6."
     Total visual magnitude estimates (cf. IAUC 4892):  Oct. 31.76
UT, 6.3 (J. D. Shanklin, Cambridge, England, 10x80 binoculars);
Nov. 1.17, 5.9 (R. Haver, Monte Autore, Italy, 15x80 binoculars);
3.50, 6.9 (A. Hale, Las Cruces, NM, 10x50 binoculars); 4.55, 6.6
(C. S. Morris, Pine Mountain Club, CA, 20x80 binoculars); 5.54, 6.2
(Morris; tail about 1 deg); 6.46, 6.1 (G. Kronk, Troy, IL, 20x80
binoculars); 8.17, 5.4 (Haver; 3-deg tail in p.a. 333 deg); 9.20,
5.8 (P. Schmeer, Bischmisheim, W. Germany, 20x80 binoculars; 0.4-deg
tail in p.a. 341 deg); 10.42, 6.3 (J. E. Bortle, Stormville, NY,
10x50 binoculars; 1.6-deg tail in p.a. 332 deg); 11.48, 6.0 (Kronk;
1 deg tail); 12.46, 5.6 (Kronk).


1989 November 13               (4904)             Daniel W. E. Green

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