Central Bureau for Astronomical Telegrams
IAUC 6038: 1993e; PSR 0833-45
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 6039
.dvi or
.ps format.
Circular No. 6038
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@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)
PERIODIC COMET SHOEMAKER-LEVY 9 (1993e)
For the Hubble Space Telescope (HST) Team, K. S. Noll, Space
Telescope Science Institute, reports the following results: "In a
spectrum of the G impact site obtained on July 21.67 UT, we observe
strong emission from Mg+ at 279.9 and 280.4 nm, from neutral Mg at
285.2 nm, and from CS at 257.8 nm. At least six weaker emission
lines correspond to neutral iron. Additional weak spectral features
may correspond to emission from other atoms or molecules. The G
impact site was close to the limb at the time of our observations,
and a portion of our aperture may have extended beyond Jupiter's limb."
R. Hunstead and D. Campbell-Wilson, University of Sydney,
report the results of observations of Jupiter over the period July
12-13 and 15-23 using the Molonglo Observatory Synthesis Telescope
(MOST) at 843 MHz: "The planet was tracked for 9 hr (4.5 hr on
either side of about 8h30m UT each day). Preliminary images have
been formed and averaged over each 9-hr integration. Integrated
flux densities have been measured in a consistent way on each image
and show an essentially constant value over the period July 12-16,
followed by a steady increase in flux density over the 7-day
duration of the SL9 impacts. The overall increase of 50 percent
from July 16 to 23 is highly significant and completely unexpected.
Further monitoring is continuing with MOST, and a more detailed
analysis of these (and earlier) observations is underway. Other
observatories, particularly those operating at frequencies < 1 GHz,
are encouraged to continue monitoring Jupiter to define better the
spectrum of the enhanced emission."
PSR 0833-45
C. Flanagan, Hartebeesthoek Radio Astronomy Observatory,
Johannesburg, reports: "PSR 0833-45 (the Vela pulsar) underwent a
spin-up of relative magnitude dP/P = -8.35(2) x 10E-7 on July
26.057 UT. This is the tenth such large 'glitch' observed from
this pulsar. Observations at Hartebeesthoek commenced 4.3 hr after
the extrapolated glitch epoch."
P. M. McCulloch, University of Tasmania, writes: "The
frequency of the Vela pulsar PSR 0833-45 increased abruptly around
July 26.060 UT; a change in pulse frequency of 9.635 x 10E-6 Hz
occurred at this time. The glitch, which is of similar magnitude
to previous events, was observed at 635 and 990 MHz from the Mount
Pleasant radio astronomy observatory, Hobart."
1994 July 27 (6038) Daniel W. E. Green
Read IAUC 6039
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
