GX 339-4 : Significant decline in IR and Optical
ATel #316; M. M. Buxton, C. D. Bailyn (Yale)
on 9 Aug 2004; 19:14 UT
Credential Certification: Michelle Buxton (buxton@astro.yale.edu)
Subjects: Binary, Black Hole, Transient
Referred to by ATel #: 318, 322
We have been making daily optical and infrared observations of the black-hole candidate
and microquasar GX 339-4 using ANDICAM on the SMARTS 1.3m telescope at CTIO. Data
obtained on UT Aug 05, 06 and 08 show that GX 339-4 has become significantly fainter
since UT Jul 31, and that the magnitude of this change increases with wavelength.
The difference in magnitude between UT Jul 31 and UT Aug 08 are as follows:
dV=0.14, dI=0.26, dJ=0.50, dH=0.68. The magnitudes as of UT Aug 08 are
as follows: V=16.2, I=14.4, J=14.0, H=13.4. Sharp rises dominated by the
IR have been observed in several sources, and have been interpreted as the
onset of synchrotron emission associated with a jet (e.g. Buxton & Bailyn 2004
ApJ, accepted, astro-ph/0408156 and references therein). By analogy,
this oppositely directed event might mark an abrupt end to jet
activity, suggesting that GX 339-4 may have up until now been in an active
'jet state' but with different characteristics in the light curve to that
seen in 2002/2003. Our most recent V- and J-band light curves can be seen
at http://www.astro.yale.edu/buxton/smarts/light_curves/gx339.html.
GX 339-4 Light Curves
