Central Bureau for Astronomical Telegrams
IAUC 4087: V1341 Cyg; HD 152408; V348 Sgr
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Read IAUC 4088
Circular No. 4087
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-495-7244/7440/7444
V1341 CYGNI
J. P. Norris and K. S. Wood, Naval Research Laboratory, write:
"HEAO A-1 data from an 8-hr pointed observation of V1341 Cyg = Cyg
X-2 from 1978 Dec. 1.354 to 1.667 UT with 5-ms time resolution
exhibit intermittent quasiperiodic oscillations similar in character
to those reported by Hasinger et al. (IAUC 4070); however, the
mean frequency of the quasiperiodic oscillations detected during
our observation is 5 Hz, approximately a factor of 8 lower than
the 30 to 50 Hz reported by Hasinger et al. Several highly significant
detections (> 100-sigma) were made during a 3-hr period, followed
by periods of nondetection up to 20 min in duration and then
subsequent reappearance at the original strength. Variations in
the centroid of the oscillations from 4 to 6 Hz are seen in 100-s
integrations. The peak width (FWHM) is variable (0.75 to 3.5 Hz)
on timescales as short as 40 s. The maximum integrated excess
power in the quasiperiodic oscillations corresponds to ~ 2 percent
of the steady source flux (1.5 x 10**4 cts m**-2 s**-1, 0.5 to 25 keV).
The strength (or absence) of red noise does not appear to be
correlated with the frequency or power of the oscillations."
HD 152408
S. Jeffers, York University, Ontario; and W. G. Weller, Cerro
Tololo Interamerican Observatory, communicate: "Analysis of low-
dispersion spectra (360-500 nm, delta-lambda = 0.9 nm) obtained on six
consecutive nights (1974 May 30-June 4) shows remarkable and repeatable
spectral variability. The spectra obtained on the first two
nights are very similar with H-beta, He II 468.6-nm and N III 463.4-nm
of comparable strength relative to continuum. On June 1 He II
468.6-nm is reduced by a factor of 3, N III by a factor of 2--both
lines being broadened by a factor of 2. Strong absorptions appear
shortward of H-beta at -2400 and 4000 km/s. On June 2 the spectrum is
identical to that on June 1. On June 3 the spectrum is identical
to that on May 31, and on June 4 the spectrum is identical to that
on June 1. This regularity suggests that a periodicity may be
present with P < 1 day. More observations are urged."
V348 SAGITTARII
Visual magnitude estimates by M. Verdenet, Bourbon-Lancy,
France: June 20.9 UT, 12.5; July 6.9, 12.6; 7.9, 12.5.
1985 July 26 (4087) Brian G. Marsden
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