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IAUC 5608: AM Her; GRO J0422+32; N Cyg 1992 AND N Sco 1992

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                                                  Circular No. 5608
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)


AM HERCULIS
     N. M. Shakhovskoj, S. V. Kolesnikov, I. L. Andronov, and I. Yu.
Alexeev write:  "An unprecedented flare of AM Her during its recent
deep low state was observed simultaneously with the 2.6-m and 1.25-
m telescopes of the Crimean Astrophysical Observatory.  After a
phase of nearly constant brightness (V = 15.40, U-B = -0.68, B-V =
+0.18, V-R = +0.61, R-I = +1.23; time resolution 24 s at the 1.25-m
telescope), a flare to V = 13.26 (U-B = -0.85, B-V = -0.04, V-R =
+0.18, R-I = +0.36) occurred on Aug. 29.86123 UT.  The rise of 2.12
mag in R (time resolution 4 s, 2.6-m telescope) lasted 2.4 min.  The
mean value of circular polarization during the flare was zero within
an error of 0.1 percent.  Characteristic e-folding time was 6.1
min in B.  The amplitudes, colors, and timescale argue for a flare
of a secondary M-dwarf in a binary system, rather than for an
accretion event with cyclotron emission."


GRO J0422+32
     A. Vikhlinin, A. Finoguenov, A. Sitdikov, R. Sunyaev, A.
Goldwurm, J. Paul, P. Mandrou, and P. Techine, on behalf of the
Granat team (Space Research Institute, Moscow; Service d'Astrophysique
du CEA, Saclay; Centre d'Etude Spatiale de Rayonnements,
Toulouse), report:  "GRO J0422+32 has been observed by SIGMA/Granat
on Aug. 22 in high-time-resolution mode.  The quasiperiodic
oscillations of flux 40-150 keV were clearly detected at two different
frequencies.  The QPO peak centroid at 0.28 Hz has FWHM = 0.13 Hz
and is bright in the whole 40- to 150-keV band.  The QPO peak
centered at 0.035 Hz (FWHM = 0.02 Hz) is bright mainly in the 40- to
70-keV band.  QPO detection for this source was reported also by
BATSE (IAUC 5592).  During subsequent observations of GRO J0422+32
from Aug. 15 to Sept. 6, the 40- to 150-keV source flux was
decreasing monotonically from 2.91 +/- 0.01 Crab to 1.85 +/- 0.01
Crab, with an approximate exponential decay time of 44 +/- 2 days.
This result is based on 270 hr of observation, divided into 12
separate sessions."


NOVA CYGNI 1992 AND NOVA SCORPII 1992
     Corrigendum.  The CCD magnitudes from W. Liller reported on
IAUC 5605 were of N Sco 1992, not N Cyg 1992.


1992 September 9               (5608)            Daniel W. E. Green

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