Circular No. 8403
             Central Bureau for Astronomical Telegrams
              INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, 
U.S.A.IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) 
CBAT@CFA.HARVARD.EDU (science) URL 
http://cfa-www.harvard.edu/iau/cbat.html  ISSN 0081-0304 Phone 
617-495-7440/7244/7444 (for emergency use only)


PKS 0405-385
      G. Cimo, S. Ellingsen, S. Carter, and P. McCulloch, University of 
Tasmania; and D. Jauncey and J. Lovell, Australia Telescope National 
Facility, CSIRO, write: "We have observed a new episode of rapid 
variability in the flux density of the quasar PKS 0405-385 on hourly 
time scales.  VLBI observations with the Australian Long Baseline Array 
at 2.2 GHz in Apr. 2004 revealed variations at a level of 10 percent 
with a period of 2 hr superimposed on a mean flux density of about 1.6 
Jy.  Observations at 6.7 GHz with the University of Tasmania Ceduna 30-m 
radio telescope over 10 days in August show that this variability 
currently continues.  Since its discovery in 1996 (IAUC 6418), PKS 
0405-385 has shown episodic periods of extremely fast (intra-hour) 
variability at centimeter radio wavelengths due to interstellar 
scintillation.  The source has alternated between long periods (years) 
of quiescence and short (a few months) periods of intense activity.  The 
reasons for the sudden change in behavior are not understood, and 
observations at radio and other wavelengths during the current active 
phase are encouraged."


SUPERNOVA 2004ef IN UGC 12158
      G. Folatelli, Las Campanas Observatory, together with M. Hamuy and 
N. Morrell, on behalf of the Carnegie Supernova Project, report that two 
optical spectra (range 400-730 nm) of SN 2004ef (cf. IAUC 8399), taken 
by W. Krzeminski on Sept. 7.16 UT with the Las Campanas 2.5-m du Pont 
telescope (+ Modular Spectrograph) and by J. Maza and E. Treister on 
Sept. 8.18 with the 6.5-m Clay telescope (+ Boller & Chivens 
Spectrograph), reveal that this is a type-Ia supernova, supported by the 
presence of Si II at 635.5, 413.0, and 597.2 nm and by S II at 545.4 and 
564.0 nm.  Similar spectral features have been observed in spectra of 
the normal type-Ia supernovae 1994D and 1999ee at 10 days before 
maximum, which suggests an early phase for 2004ef.  The minimum of the 
Si II 635.5-nm line yields high expansion velocities of 16200 and 14500 
km/s on each night, respectively, assuming the NED host-galaxy recession 
velocity of 9290 km/s.  An upper limit of 0.05 nm is given to the 
equivalent width of the interstellar Na I D line, indicating a low 
reddening by dust in the host galaxy.


COMET C/2004 Q1 (TUCKER)
      J. J. Gonzalez, Leon, Spain, reports visual total mag 12.9 and coma 
diameter 1'.5 on Aug. 26.14 UT (0.20-m reflector).

                       (C) Copyright 2004 CBAT
2004 September 9               (8403)            Daniel W. E. Green