Abstract. In many radiative proton capture reactions important in H-burning in novae and XRBs, the resonant parts play the major role. I will show how one can use decay spectroscopy techniques to find these resonances and study their properties. I will exemplify with techniques developed at Texas A&M University to measure -and -delayed proton decay, applied to sd-shell, proton-rich nuclei produced and separated with the MARS recoil spectrometer. The short-lived radioactive species are produced in-flight, separated, slowed down from about 30-40 MeV/u and implanted in the middle of very thin Si detectors. This allowed us to measure protons with energies as low as 200-400 keV from nuclei with lifetimes of 100 ms or less. At the same time we measured gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of 23 Al, 27 P and 31 Cl. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and worked even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions 22 Na(p,) 23 Mg (crucial for the depletion of 22 Na in novae), 26mAl(p,) 27 Si and 30 P(p,) 31 S (bottleneck in novae and XRB burning), respectively. At the same time the decay properties were established for these 3 isotopes, which were cleanly separated here for the first time. Their lifetimes were measured; the IAS states and their decay were un-equivocally located. I will briefly show how a recent detector development allows better measurements in the critical region of proton energies 100-400 keV.