Flare at OIR wavelengths in GX 339-4
ATel #1109; Michelle Buxton (Columbia University) and Charles Bailyn (Yale University)
on 14 Jun 2007; 18:39 UT
Credential Certification: Michelle Buxton (buxton@astro.yale.edu)
Subjects: Infra-Red, Optical, Binary, Black Hole, Transient
We have continued our observations of GX 339-4 with the SMARTS 1.3m and ANDICAM instrument since the source transitioned into the hard state around MJD 54233 (13th May 2007, ATEL #1074). The optical and infrared (OIR) fluxes reached a minimum at MJD 54239, and then began to rise. Since that time the brightness of the source has increased as follows:
Filter | Mag at MJD 54239 | Mag at MJD 54260 | Delta (mag) |
V | 17.6 | 17.0 | 0.6 |
I | 16.7 | 15.8 | 0.9 |
J | 15.5 | 14.0 | 1.5 |
H | 15.0 | 13.3 | 1.7 |
The large increase in the infrared implies that this is likely an IR-dominated flare, like that seen for example in 4U1543-47 (Buxton & Bailyn 2004 ApJ 615, 880). The latest observations suggest that the OIR fluxes may now have peaked. Observations in other wavelengths, especially infrared and radio, are strongly encouraged.
A plot of our lightcurves can be found at the URL provided below.