Multiwavelength evolution of GROJ1655-40
ATel #486; D. A. Smith (U. of Michigan)
on 11 May 2005; 15:47 UT
Credential Certification: Donald A. Smith (dasmith@space.mit.edu)
Subjects: Optical, X-ray, Black Hole, Transient
ROTSE-III monitoring of GRO J1655-40 reveals that over the last 24 hours, the optical intensity of this source has declined significantly. For the last forty days, it has remained near an unfiltered
magnitude of 14.2 (calibrated to the USNO A2.0 R-band catalog), but at MJD 53500.489 it dropped to
14.7±0.2, and since 53501.0, it has remained within 0.1 mags of 15.1.
Meanwhile, the ASM quicktime analysis reveals that the 2-12 keV X-ray intensity has been
rapidly flaring between levels of 2.0±0.1 to 4.4±0.1 Crab over the same time
interval (using the individual 90-s dwells). Examination of the three sub-bands indicate
a hardening of the spectrum.
Thanks to the RXTE/ASM teams at MIT and NASA/GSFC. Also thanks to the members of the ROTSE collaboration at UNSW Sydney, Siding Spring Observatory, MPI-Heidelberg, and the HESS team in Namibia.
ROTSE and RXTE/ASM light curve
