Central Bureau for Astronomical Telegrams
IAUC 4034: 1982i; (3200)
The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).
Read IAUC 4035
Circular No. 4034
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)
M. Hanner and A. Tokunaga, Jet Propulsion Laboratory, report
observation at 1.25 microns on Jan 18.3 UT at the 3-m NASA Infrared
Telescope Facility, Mauna Kea. A 30-min integration gave J = 18.4
+/- 0.2. This result is consistent to within 20 percent of the
first infrared detection by Birkett et al. (IAUC 4025) on 1984
Dec. 20. A 3-sigma upper limit of K = 18.7 was obtained at 2.2 microns,
indicating a very blue color compared to the sun and other comets.
C. Morbey, Dominion Astrophysical Observatory, telexes: "A
list of 41 magnitude observations from three independent groups
(Lefevre et al. 1984, A. Ap. 138, L1; West and Pedersen 1984, ibid.
138, L9; Jewitt and Danielson 1984, Icarus 60, 435) was searched
for possible periods between 0.2 and 10.0 days. One significant
group of periods was isolated: 2.005, 0.684, 0.406 and 0.290 days
(cf. IAUC 3943, 3957). Omission of the faintest data point from
the Lefevre data greatly improved the quality of these periods.
Confidence-level calculations show that periods as good as the
2.005-day period can be found in random data (with the same
magnitude range and epochs of observation as the published data) in
only 7 percent of random data sets. Of the other periods, which
are aliases of the 2.005-day period based on a one-day observation
interval, the most significant is 0.684 day; periods of equal
quality are found in 16 percent of random data sets. The
brightness variation (~ 1.6 mag) for both periods is basically saw-
toothed and has a scatter of 0.22 and 0.24 mag, respectively. The
0.406-day and 0.290-day periods appear to be ruled out by the
Jewitt-Danielson data. Appropriate observations are required to
confirm either the 2.005-day or the 0.684-day period."
(3200) 1983 TB
D. J. Tholen writes: "Broad-band photoelectric photometry at
five wavelengths between 0.3 and 0.9 microns was obtained on 1983 Nov.
8, 9, 10, and 1984 Dec. 5, 29, 31 with the Mauna Kea Observatory's
2.24-m telescope. All six observations show the colors of (3200)
to be slightly bluer than the sun, implying an F classification.
These data contradict the S-class colors reported by Cochran and
Barker (1984, Icarus 59, 296) and Belton et al. (IAUC 4029), based
on single spectroscopic observations. In addition, the late
December observations yielded a lightcurve amplitude in excess of
0.4 mag, and a rotational period probably slightly under 4 hr."
1985 February 8 (4034) Brian G. Marsden
Read IAUC 4035
Our Web policy. Index to the CBAT/MPC/ICQ pages.
