Central Bureau for Astronomical Telegrams
IAUC 4798: V1521 Cyg (CYGNUS X-3); 1989L; 3C 279
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Read IAUC 4799
Circular No. 4798
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
V1521 CYGNI (CYGNUS X-3)
E. B. Waltman, R. L. Fiedler, and K. J. Johnston, Naval
Research Laboratory, communicate: "The source V1521 Cyg (Cygnus X-3)
is currently flaring. It reached a peak of 17 Jy at 8.085 GHz
on June 2 and 14 Jy at 2.7 GHz on June 3. By June 5 it had
dropped to a level of 3 Jy, and it has been variable at
the 1-3 Jy level since then. This is the first major flare in
V1521 Cyg since 1985. Based on previous history, it could
possibly flare again in the next few weeks. The source position is:
R.A. = 20h30m37.62, Decl. = +40 47'12.8 (equinox 1950.0). These
observations were performed using the Green Bank interferometer,
operated by the National Radio Astronomy Observatory for NRL and
the U.S. Naval Observatory."
SUPERNOVA 1989L IN NGC 7339
M. Phillips, Cerro Tololo Interamerican Observatory, reports:
"N. D. Tyson and M. Rich, Columbia University, have obtained broadband
CCD images of SN 1989L with the CTIO 0.9-m telescope. Preliminary
measurements give B = 15.5 and V = 15.4 for June 6.43 UT, with the
supernova apparently having faded slightly by the next night. A low
signal-to-noise spectrum obtained on June 6 by M. Hamuy with the Yale
1.0-m telescope shows a broad emission line at a wavelength of
about 659 nm that is best identified with H-alpha. The
supernova is therefore most likely of type II."
3C 279
P. Garcia-Lario, M. Kidger, and J. de Diego, Instituto
de Astrofisica de Canarias, write: "Infrared observations taken
with the 1.5-m Carlos Sanchez Telescope, Observatorio del Teide,
Tenerife, show that this object was again in outburst at the end
of May. The magnitude in K declined from 10.14 on May 27 to
10.61 on June 4. The former is more than half a magnitude brighter
than previous measures in January (cf. IAUC 4739). The decline
was accompanied by the expected reddening of the continuum. (H-K)
increased from +0.77 on May 30 to +1.08 on June 6. In view of the
considerable brightening in the visible registered by Sadun et al.
(IAUC 4780) in early April, it is possible that the measures
reported here represent only the tail of the outburst and not the
maximum. We urge the examination of patrol images from this epoch to
attempt to confirm this suggestion."
1989 June 14 (4798) Daniel W. E. Green
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