Central Bureau for Astronomical Telegrams
IAUC 3586: 3A 1431-409 = V532 Cen; SN IN NGC 1316; GX 339-4
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Circular No. 3586
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 617-864-5758
3A 1431-409 = V532 CENTAURI
I. McHardy and J. Pye, X-Ray Astronomy Group, Leicester University;
and T. Fairall, University of Cape Town, telex: "We have
found the very probable identification of the transient x-ray
source 3A 1431-409, first noted by B. Cooke (1976, Nature, 262, 195),
with the irregular 13th-magnitude variable V532 Cen. Spectroscopic
image-photon-counting system observations by Fairall at the South
African Astronomical Observatory revealed very strong double-peaked
H-alpha emission (overall width at zero-intensity = 500 km/s), weaker
C III/N III emission (462.0 nm) and also probably some He I emission.
The two components of H-alpha were at 656.35 and 656.00 nm on Mar.
8 and 10, respectively, but were both red-shifted by 0.08 nm on Mar.
9. The redward component is typically ~ 2.5 times stronger than
the blue one, although slight changes in this ratio, and in the
line profiles, do occur. New measurements give the position of
V532 Cen as R.A. = 14h33m34s.3, Decl. = -40o59'32" (uncertainty +/- 2";
equinox 1950.0). These observations strongly suggest that V532 Cen is
a cataclysmic variable seen probably pole-on, thereby suggesting
the identification with 3A 1431-409."
SUPERNOVA IN NGC 1316
P. Salinari, Osservatorio Astrifisico di Arcetri; and A. F. N.
Moorwood, European Southern Observatory, Garching, communicate the
following magnitudes of Evan's supernova in NGC 1316 (cf. IAUC 3583),
obtained on Mar. 20d23h30m UT with the ESO 3.6-m telescope: J =
13.64 +/- 0.05, H= 13.52 +/- 0.05, K = 13.35 +/- 0.1.
GX 339-4
S. A. Ilovaisky, Observatoire de Meudon, reports: "C. Chevalier
and I have found that observations made with the European Southern
Observatory's 3.6-m telescope on Mar. 6-8 UT reveal that the optical
counterpart to the x-ray source GX 339-4 (= 4U 1658-48) continues
to be in an extremely faint state, being then invisible in the
photometer viewer (limiting magnitude: V ~ 19.5). A 90-min exposure
with the ESO 1-m Schmidt telescope obtained under excellent
conditions on Mar. 8 shows, however, a faint (B > = 21) star at the
position of the source; this is at least 4 magnitudes below previously
reported values (cf. Grindlay 1979, A .J. Letters, 232, L33).
We strongly urge x-ray and optical observers to monitor this source."
1981 March 25 (3586) Daniel W. E. Green
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