Central Bureau for Astronomical Telegrams
IAUC 4159: Sats OF URANUS AND NEPTUNE; 1982i
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 4160
Circular No. 4159
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
SATELLITES OF URANUS AND NEPTUNE
C. Hansen and B. Smith, on behalf of the Voyager Imaging
Science Team, report the discovery of a new satellite of Uranus.
The object, provisionally designated 1985 U1, is ~ 75 km in
diameter and at a distance of 86 000 km from the center of Uranus.
D. Bonneau and R. Foy, CERGA, report that speckle interferometric
observations on the 3.6-m Canada-France-Hawaii Telescope
during 1984 May 27-29 lead to the following first direct measurements
of the uniform disk diameters of the principal satellites of
Uranus and Neptune: Uranus I (Ariel), angular diameter 0"103 +/-
0"003, corresponding to 1325 + 46 km; Uranus II (Umbriel), 0"079 +/-
0"003, 1025 +/- 33 km; Uranus III (Titania), 0"120 +/- 0"004, 1561 +/-
46 km; Uranus IV (Oberon), 0"120 +/- 0"004, 1561 +/- 46 km; Neptune I
(Triton), 0"098 +/- 0"003, 2074 +/- 64 km.
PERIODIC COMET HALLEY (1982i)
S. M. Larson, Lunar and Planetary Laboratory, reports that
CCD images obtained by D. Levy and himself with the 1.5-m reflector
at the Catalina station on Jan. 6.1 UT show the result of a
major outburst. A complex of curved sunward jets and a bright,
linear, antisolar 38" jet appears to be the same type of event
seen several times in the 1910 photographs. The comet has been
showing episodes of activity in roughly two-day cycles, and on
Jan. 5.1 only remnants of the Jan. 4.1 jets were seen. Since such
events may lead to a better determination of the nuclear rotation
period, observers are urged to watch for recurrences of the phenomenon
at multiples of the 2.17-day period reported by Sekanina on
IAUC 4151 (note also the communication by Itoh with Suisei
observations on IAUC 4155). Spectra over the range 380-950 nm taken
with the same instrument showed no unusual emissions.
J. Crovisier, Observatoire de Meudon, telexes that high-
resolution Fourier-transform infrared spectra were recorded on
1985 Dec. 19-23 at the Canada-France-Hawaii Telescope by J.-P.
Maillard, T. Encrenaz, M. Combes and himself. Spectra in the 4.7
micron region at 0.005 mm**-1 resolution show no CO emission; a preliminary
upper limit of 10**28 s**-1 can be derived for the CO production
rate. Other spectra with about 100 mm**-1 resolution were obtained
over 0.9-2.5 microns; the (0-0) band at 1.10 microns and the (1-0) band at
0.92 microns of the CN red system are clearly visible.
1986 January 9 (4159) Brian G. Marsden
Read IAUC 4160
Our Web policy. Index to the CBAT/MPC/ICQ pages.
