Central Bureau for Astronomical Telegrams
IAUC 5281: V1333 Aql; 3C 345; NOTICE TO SUBSCRIBERS
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Read IAUC 5282
Circular No. 5281
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
V1333 AQUILAE
S. A. Ilovaisky and C. Chevalier, Observatoire de Haute-Provence,
write: "CCD photometry of the optical counterpart of this recurrent
transient low-mass x-ray binary, obtained with the 1.2-m Haute Provence
reflector during Apr. 9-May 25, shows that the object has now left
quiescence, having started to brighten some time between May 13 and 23.
This probably signals the onset of yet another yearly activity cycle,
the third detected by our monitoring program; the last one started early
in 1990 June and lasted five months (cf. IAUC 5036, 5107). Further CCD
monitoring will continue at OHP throughout the observing season.
Observations at other wavelengths are highly desirable."
3C 345
F. Makino and T. Kii, Institute of Space and Astronautical Science,
Sagamihara, Kanagawa, Japan; T. Ohashi, Department of Physics,
University of Tokyo; H. Terasranta, Metsahovi Radio Research Station,
Kylmala, Finland; and the Ginga Team, report: "X-ray observation of the
quasar 3C 345 during May 25.2-25.8 UT with the Ginga satellite showed
the flux at 2-10 keV to be 9 (+/- 3) x 10**-12 erg cm-2 s-1. The
spectrum is described by a power-law model with an energy index of 0.55
+/- 0.15 and absorbing hydrogen column less than 10**22 cm-2. The x-ray
flux has essentially doubled from the level at our previous observation
on 1989 Apr. 27. Long-term monitoring of the radio flux at the
Metsahovi Station showed an increase in the 37-GHz flux from 4.2 +/- 0.2
Jy in 1989 Apr. to 12.7 +/- 0.2 Jy on 1991 May 27; the 37-GHz flux is at
its highest level since the flux rise started in 1989 Oct. and seems
still to be increasing. Infrared, optical and ultraviolet observations
are encouraged."
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1991 June 1 (5281) Brian G. Marsden
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