ISF 3.4

The left panel shows precision observations of X-ray burst light curves from GS 1826-
24 by the RXTE observatory. The observations reveal systematic light curve changes from observations
in the years 1997-1998 (blue) to observations in 2000 (red) that are likely related to
changes in the accretion rate. Such measurements provide an excellent testing ground for X-ray
burst models. The panel on the right shows predictions of X-ray burst light curves from state-ofthe-
art one-dimensional model calculations. The various curves are obtained for different assumptions
on the nuclear physics of the rp-process. To approximate nuclear physics uncertainties
that influence the effective lifetimes of the nuclei in the rp-process, β+ and electron capture
rates of two groups of nuclei (with A > 56 and with A > 27) have been increased and decreased by
a factor of ten. Current precision in nuclear physics is not adequate to fully interpret the observations. Adapted from [Gal04,Gal06a] (left) and [Woo04] (right).

References:
[Gal04] D.K. Galloway et al., Ap. J. 601, 466 (2004)
[Gal06a] D.K. Galloway, private communication
[Woo04] S.E. Woosley et al., Ap. J. Suppl. 151, 75 (2004)