New Features Added summed_flag to power_confidence_limits, to make it work with averaged powers too. (#952) Add function to save spectra in Xspec-compatible format (#957) Add possibility to save to Xspec format for covariance/variability spectra (#963) Improve treatment of coherence (#965) Bug Fixes Fixed EventList.read to properly pass **kwargs. (#950) Fixed an error in power_confidence_limits that led to systematically narrower confidence intervals. (#951) Fixed uncertainty propogation error in Lightcurve.rebin() (#953) Fixed convergence issues in power_upper_limit for summed powers and low count rates by replacing minimize with brentq. (#954) Fix initialization of countrate_err if errors are Poisson (#958) Fix array_attrs property of Lightcurve (#959) Speedup and improve robustness of fill_bad_time_intervals (#968)