Central Bureau for Astronomical Telegrams
IAUC 4155: 1982i
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Circular No. 4155
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 HALLEY (1982i)
T. Itoh and the Comet Halley Mission Team, Institute of Space
and Astronautical Science, telex that the Ly-alpha imager of the
spacecraft Suisei has taken several hundred images of P/Halley since Nov.
14. The H coma of the comet is very active, showing a periodic radiance
variation (period 2.2 days) during Nov. 26-Dec. 13. Two sources
are contributors to this activity: a weak jet, followed by another
strong jet occurring with ~ 20 hr delay. The jet activity
overwhelms other cometary activity at r = 1.6-1.3 AU. The brightest
outburst observed thus far was visible on images taken Dec. 16-18,
and started Dec. 16.83 UT in the vicinity of the strong jet source.
Similar outbursts were observed on Dec. 19.00, 19.83, and 25-26.
$B
H. Campins, Planetary Science Institute, reports: "Infrared
spectra of P/Halley in the 5-8-, 15-30-, and 20-65-micron regions have
been obtained from NASA's Kuiper Airborne Observatory using grating
spectrometers from Ames Research Center, Cornell University, and
Goddard Space Flight Center, respectively. Preliminary analysis of
the observations shows a strong continuum in addition to weak
spectral structure (not yet identified) in all 3 wavelength regions.
Fluxes for wavelengths of interest to ground-based observers: Dec.
12 UT (20" aperture), 7.5 Jy at 5 microns, 16.7 Jy at 8 microns; Dec. 17
(45" aperture), 243, 200, and 162 Jy at 20, 25, and 30 microns, respectively
(typical errors 5 percent). The 5-8-micron region was observed by L.
Allamandolla, J. Bregman, H. Campins, D. Rank, F. Witteborn, and D.
Wooden; 15-30 region by Campins, G. Gull, T. Herter, and J. Houck;
20-65 region by Campins, W. Glaccum, R. Lowenstein and H. Moseley."
C. Barbieri and F. Sabbadin, Asiago Astrophysical Observatory,
telex information obtained from a series of 103a-O plates taken via
0.67- and 0.40-m Schmidt telescopes. Coma diameter: 18', 16', 20',
18', and 12' on Dec. 12.8, 13.8, 14.8, 15.8, and 16.8 UT,
respectively. Lengths of tails: Dec. 12.75-12.84, 104' (p.a. 65,
irregular; several thin filaments; pronounced distortion 32' from
nucleus), 16' (p.a. 45, faint, straight); 13.72-13.83, p.a. 65 (
homogeneous, straight; disturbance 26' from nucleus); 14.72-14.88,
160' (p.a. 65, irregular, filamentary, noticeable changes in 4 hr;
bright condensation ~ 68' from nucleus), 40' (p.a. 75, fainter,
curved); 15.75-15.88, 128' (p.a. 67 close to, and ~ 80 when > 43'
from, nucleus), 48' (p.a. 60, straight), 24' (p.a. 50, straight);
16.73-16.88, 120' (p.a. 62), 16' (p.a. 70), 24' (p.a. 50).
1985 December 30 (4155) Daniel W. E. Green
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