Central Bureau for Astronomical Telegrams
IAUC 4178: Sats OF SATURN; 1982i
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Circular No. 4178
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 SATURN
E. A. Marouf and G. L. Tyler, Department of Electric
Engineering, Stanford University, write that they infer the presence
of two satellites shepherding a ringlet within the Cassini division.
This inference was made from the wakes induced in neighboring
streamlines of ring particles, subsequently sensed in the extinction
profile of a 0.036-m monochromatic radio signal transmitted
by Voyager 1 through the rings back to the earth. With the
help of new techniques for removing diffraction effects from the
measurements it was possible to reconstruct the profile with radial
resolution better than 1 km, so although there was no direct
detection of the satellites, sufficient information about them
could be obtained to warrant the assignment of provisional
designations. 1980 S35 had orbital radius r = 118 213 km (assuming the
position of Saturn's north pole to be R.A. = 38.409 deg, Decl. = +83.324
deg) and longitude lambda = 107.7 deg (measured in the ring plane from the
ascending node on the earth's mean equator for 1950.0) at the epoch 1980
Nov. 13.20462 UTC; its mass (relative to Saturn) m = 4-8 x 10**-12,
yielding (for assumed density 1 g cm**-3) radius R = 8-10 km. 1980
S36 had r = 118 269 km, lambda = 83.2 deg, m = 1-2.5 x 10**-11, R = 11-15 km.
PERIODIC COMET HALLEY (1982i)
D. Bockelee-Morvan, Observatoire de Meudon; D. Despois,
Observatoire de Bordeaux; J. Schraml, Max-Planck-Institut fur
Radioastronomie; J. Crovisier and E. Gerard, Observatoire de Meudon;
and T. Forveille, Universite de Grenoble, report the observation
at 88.6 GHz of the J=1-0 lines of HCN with the IRAM telescope on
Feb. 10 and 12. The equivalent brightness temperature was 0.200 +/-
0.040 K for the main hyperfine component. The line was centered
on the comet's rest velocity with a line width of 2.6 km/s. The
hyperfine component intensity ratios were normal. The
corresponding HCN production rate was ~ 2 x 10**27 s**-1.
E. P. Ney and A. G. Knutson, University of Minnesota, report
the following infrared magnitudes, measured with a 26" diaphragm
at the O'Brien Observatory: Jan. 26.8 UT, J = -, H = 4.4, K = 4.6,
L = 1.2, [4.8 microns] = -0.5, [8.6 microns] = -3.2, [10.6 microns] = -4.3,
[12.5 microns] = -4.3, [18 microns] = -5.3; Feb. 9.75, -, -, 3.6, 2.0, 0.0,
-2.6, -4.0, -3.7, -4.6; 12.7, 3.8, 3.4, 2.3, -0.1, -1.6, -3.9, -5.2,
-5.2, -5.9; 14.7, 4.3, 4.5, 3.2, 1.2, -0.4, -3.5, -4.7, -4.6, -5.4.
1986 February 20 (4178) Brian G. Marsden
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