Central Bureau for Astronomical Telegrams
IAUC 4103: 1984e; AM Her
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Circular No. 4103
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-495-7244/7440/7444
PERIODIC COMET GIACOBINI-ZINNER (1984e)
A. Tokunaga, D. Griep, W. Golisch and C. Kaminski, University
of Hawaii, report the following magnitudes obtained with the NASA
Infrared Telescope Facility on Aug. 25, using a 7"3 aperture (error
~ 0.03 mag): J = 10.8, H = 10.4, K = 10.2, L = 9.1, M = 6.8, N
= 1.4, Q = -0.5. The observations indicate a color temperature of
280 K. Narrow-band photometry shows a silicate feature that is ~
0.25 mag above the continuum level.
D. Rees, University College, London; and M. K. Wallis,
University College, Cardiff, report: "The 1-m Kapteyn telescope at La
Palma was used during Aug. 27-Sept. 3 with the Rees imaging photon
detector system to obtain narrow-waveband images of arcmin resolution
in CN, O I (558 and 630 nm), CW, H-alpha, H-beta, and the ions CO+
(mainly 402 nm) and H2O+ (580 and 700 nm). We determined the ion
tail to be 30 000 km wide at the anticipated position of the ICE
encounter (10 000 km from the head), and the tail had no apparent
dense core region. Images in the light of O+ at 732 nm were also
obtained, although the emission was extremely weak. The Doppler
imaging system mode of the instrument obtained Fabry-Perot fringes
in the light of O I (630 nm) on Sept. 2. With a 0.2-m Mead telescope
the CN coma was mapped out to a radius of 200 000 km and the
CO+ ion tail to a length of 200 000 km."
E. Leibowitz and N. Brosch, Wise Observatory, telex: "Narrow-
band photoelectric measurements near the nucleus on five nights
during July and August indicate that the blue continuum is
oscillating on a timescale of hours. Periods of 9.4 hr and probably
also 1.77 hr are strongly suggested, with amplitude 0.1 mag."
Independently of the preceding report, S. O'Meara has informed
us that his visual observations (at 725 x) with the 0.46-m
refractor at Amherst College during 70 min on Aug. 24 showed a
condensation feature and associated jet that appeared to rotate
about the nuclear condensation (~ 1" away) in a period of 1.38 hr.
AM HERCULIS
Visual magnitude estimates: May 15.9 UT, 14.9 (M. Verdenet,
Bourbon-Lancy, France); 23.9, 13.5 (Verdenet); June 13.9, 13.3
(Verdenet); July 1.9, 13.6 (Verdenet); 7.9, 14.2 (Verdenet); 14.9,
15.0 (Verdenet); Aug. 2, 13.8 (Verdenet); 9.90, 15.3 (R. Monella,
Covo, Italy); 14.88, 15.1 (Monella); 20.87, 15.1 (Monella).
1985 September 9 (4103) Brian G. Marsden
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