Central Bureau for Astronomical Telegrams
IAUC 5109: SATURN; 1990i
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Circular No. 5109
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
SATURN
Several observers have reported independent discoveries of the
new white spot on Saturn. S. Wilber (name spelled incorrectly on
IAUC 5105), Las Cruces, NM, communicates that on Sept. 25, in better
seeing than three nights later, the white spot appeared brighter and
more condensed than subsequently. His Sept. 25 observations, made
at 300x with a 0.25-m reflector, showed the spot near the center of
Saturn's disk, on the southern side of the north equatorial belt
(NEB). R. Tatum, Richmond, VA, reports that the spot was bright
enough to be seen well past the central meridian on Oct. 2.0 UT and
with a 0.10-m refractor; the object was moderately condensed and
appeared to extend into the NEB in the mediocre seeing. M. Kidger,
Instituto de Astrofisica de Canarias, reports: "Two independent
timings of the new white spot's central transit crossing by members
of the Agrupacion Astronomica de Tenerife (V. Gonzalez and F.
Hernandez; Kidger and J. Gonzalez) yield the same result: Oct. 1.951
UT. A first estimation of the rotation period from these observations
and those on IAUC 5105 is 10h15m45s +/- 49s. Timing of the
meridian crossing yields an estimate for its semimajor axis of
17 000 +/- 1000 km. Comparison with visual observations made on
Sept. 29.833 by Kidger with the 0.51-m telescope shows that the spot
appears to be evolving rapidly: it appears larger, more diffuse,
and not as bright. There has been a major disruption of the NEB in
the region of the spot. To the west, the belt is very dark and
active; to the east, it has narrowed and faded considerably."
COMET TSUCHIYA-KIUCHI (1990i)
Ephemeris extension from orbital elements on MPC 16841:
1990/91 R.A. (1950) Decl. Delta r m1
Oct. 16 10 52.92 - 1 32.2 1.750 1.133 7.3
26 10 39.84 - 6 28.9
Nov. 5 10 21.04 -12 43.5 1.363 1.253 7.2
15 9 51.56 -20 48.2
25 9 01.97 -30 46.7 1.017 1.431 7.1
Dec. 5 7 39.64 -40 22.2
15 5 51.77 -44 16.7 0.990 1.640 7.6
25 4 21.57 -41 22.2
Jan. 4 3 27.06 -36 01.7 1.372 1.864 8.9
1990 October 2 (5109) Daniel W. E. Green
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