Abstract : In this review, we emphasize the interplay between astrophysical observations, modeling, and
nuclear physics laboratory experiments. Several important nuclear cross sections for astrophysics have
long been identified, e.g., 12C(α, γ)16O for stellar evolution, or 13C(α, n)16O and 22Ne(α, n)25Mg as neutron
sources for the s-process. More recently, observations of lithium abundances in the oldest stars, or of nuclear
gamma-ray lines from space, have required new laboratory experiments. New evaluation of thermonuclear
reaction rates now includes the associated rate uncertainties that are used in astrophysical models to
i) estimate final uncertainties on nucleosynthesis yields and ii) identify those reactions that require further
experimental investigation. Sometimes direct cross section measurements are possible, but more generally
the use of indirect methods is compulsory in view of the very low cross sections. Non-thermal processes are
often overlooked but are also important for nuclear astrophysics, e.g., in gamma-ray emission from solar
flares or in the interaction of cosmic rays with matter, and also motivate laboratory experiments. Finally,
we show that beyond the historical motivations of nuclear astrophysics, understanding i) the energy sources
that drive stellar evolution and ii) the origin of the elements can also be used to give new insights into
physics beyond the standard model.
