Optical Variability in XTE J1118+480
ATel #389; R. I. Hynes (Louisiana State University), T. K. Watson (Southwestern University), D. E. Winget, E. L. Robinson (University of Texas at Austin)
on 14 Jan 2005; 17:20 UT
Credential Certification: Robert Hynes (rih@phys.lsu.edu)
Subjects: Optical, Binary, Black Hole, Transient
Referred to by ATel #: 399, 412
High time-resolution (1-sec) white light photometry of the outbursting black hole XTE J1118+480 (ATEL #383, #384, #385, #386, #387) was obtained with the Argos CCD photometer on the McDonald Observatory 2.1m telescope on 2005 January 13.35. Significant optical variability was detected on timescales shorter than 100s, with an rms amplitude of 3% integrated from 0.01-0.5Hz. As in the previous outburst, the power spectral density takes the form of band-limited noise, but with a higher break frequency at 0.12Hz. No quasi-periodic oscillation was detected. Further monitoring at the highest possible time-resolution (a few sec or better) is encouraged.