The optical counterpart of the black hole X-ray binary GX
339-4 has been monitored since September 2007 in V, R and
i-bands with the Faulkes Telescope South at Siding Spring,
Australia (D.M. Russell, Univ. of Amsterdam; D. Altamirano,
Univ. of Amsterdam; F. Lewis, P. Roche, C. B. Markwardt and
R.P. Fender). Optical flaring on a time scale of days has been
observed, and the mean flux is increasing. Amplitudes are of
the order of one magnitude or more, which is, as far the
investigators know, stronger than previous periods of both
outburst and low flux levels. Reported optical measurements are
:
V = 18.07 +/- 0.05 2008-05-29 MJD 54615.40
V = 17.10 +/- 0.18 2008-06-20 MJD 54637.35
It is possible that GX 339-4 is beginning a new outburst. Ref.
Astronomical Telegram AT #1586 for more details.
To see light curves for GX 339-4, go to http://staff.science.uva.nl/~davidr/faulkes/gx339.html
A four-passband sequence for GX 339-4 can be found at
http://www.astro.yale.edu/buxton/smarts/find_charts/gx339.html
The VSS, RASNZ has issued charts for GX 339-4 = V821 Ara. See charts 625 and 626 in Series 14. No comparison stars were selected. The attached chart rectifies this.
