Central Bureau for Astronomical Telegrams
IAUC 4879: V404 Cyg; GX 1+4; V854 Cen
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Read IAUC 4880
Circular No. 4879
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
V404 CYGNI
X.-H. Han, National Radio Astronomy Observatory and Beijing
Observatory, and R. M. Hjellming, National Radio Astronomy
Observatory, report: "Fluctuations on a timescale of minutes,
seen in the radio emission of V404 Cyg in nearly all Very
Large Array observations from June 1 to Sept. 1, have been found
to be quasiperiodic oscillations (QPOs) in three out of four
60- to 90-min observations made between July 22 and Aug. 29.
Significant power is found for periods between 5 and 20 min, with
peak power at 13 min on two days and at 16 min on a third day.
High-sensitivity observations of this source and its radio QPOs
are now required because of an apparent overall decay (after
June 1) described appoximately by 430(JD-2447653)E-0.83 mJy."
GX 1+4
G. K. Skinner, University of Birmingham, on behalf of the
TTM/Kvant team (IKI, U.S.S.R. Academy of Sciences; University of
Birmingham; Space Research Laboratory, Utrecht) writes: "In
view of the report of radio emission from near GX 1+4 (IAUC
4871), we have obtained a new independent position for the x-ray
source using data obtained with the TTM Coded Mask Imaging
Spectrometer on Mir during 1989 August. The centroid of the
30"-radius error circle is R.A. = 17h28m58s.3, Decl. = -24 42'28"
(equinox 1950.0). This is consistent with the Copernicus and
SAS-3 positions and with the optical candidate. It lies between
the two radio source positions and excludes both, so that neither
can be the direct counterpart of the x-ray source. We place upper
limits of 5 mJy on the 2- to 10-keV x-ray flux from the positions
on IAUC 4871."
V854 CENTAURI
Visual magnitude estimates (cf. IAUC 4821): July 16.14 UT,
8.0 (V. F. de Assis Neto, Sao Francisco, Brazil); 19.03, 8.2 (de
Assis Neto); 20.37, 8.0 (P. Williams, Heathcote, N.S.W.); 23.90,
7.9 (A. Pereira, Cabo da Roca, Portugal); Sept. 3.49, 7.4 (A.
Pearce, Scarborough, W. Australia); 13.41, 7.3 (Williams);
18.41, 7.3 (Williams); 21.38, 7.6 (Williams).
1989 October 17 (4879) Daniel W. E. Green
Read IAUC 4880
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