Top panel: overview of the 2010/2011 outburst of MAXI J1659−152. a) MAXI/GSC and b) Swift/BAT daily light curves. Note that most of the measurements after day  ~100 are non-detections. In a) we mark the times of the Swift/XRT (“X”), Chandra (“Ch”) and radio (“R”) observations taken in 2011 (see Sect. 3.1). Middle panel: zoom-in from the top panel, focusing on the main part of the 2010/2011 outburst of MAXI J1659−152. c) RXTE/PCA PCU2 light curve, at a 16 s time resolution. The data within an observation are connected to guide the eye; errors are not plotted since they are negligible. The time-span of the XMM-Newton observations, discussed in this paper, is indicated in the top-left (“XMM”). The times of the transition dips (“td”; see text) are marked by arrows. The time spans for the four main epochs described in the text (“A”, “B”, “C”, “D”) are indicated at the bottom of this graph. d) MAXI/GSC and e) Swift/BAT light curves, showing averages per satellite orbit. The vertical dotted line marks the time of the first MAXI/GSC detection (Negoro et al. 2010). f) Hardness values as a function of time. Hardness is defined as the ratio of the 0.5 day averaged count rates in the Swift/BAT 15–50 keV band to the MAXI/GSC 2–20 keV band. Bottom panel: zoom-in from the middle panel, focusing on a possible 3-day variation discussed in Sect. 3.1. g) MAXI/GSC and h) Swift/BAT light curves showing the averages over a satellite orbit, between days 15 and 31. We also show the results of a sinusoidal fit to describe the possible  ~3 day variation, plus a constant, linear and quadratic term to account for the longer-term trend, between days 18 and 28. The horizontal dotted lines in a), b), d), e), g) and h) correspond to the zero level.