  There has never been a more exciting time in the overlapping areas of nuclear
physics, particle physics and relativistic astrophysics than today. Orbiting
observatories such as the Hubble Space Telescope, Rossi X-ray Timing Explorer
(RXTE), Chandra X-ray satellite, and the X-ray Multi Mirror Mission (XMM) have
extended our vision tremendously, allowing us to see vistas with an
unprecedented clarity and angular resolution that previously were only
imagined, enabling astrophysicists for the first time ever to perform detailed
studies of large samples of galactic and extragalactic objects. On the Earth,
radio telescopes (e.g., Arecibo, Green Bank, Parkes, VLA) and instruments using
adaptive optics and other revolutionary techniques have exceeded previous
expectations of what can be accomplished from the ground. The gravitational
wave detectors LIGO, LISA VIRGO, and Geo-600 are opening up a window for the
detection of gravitational waves emitted from compact stellar objects such as
neutron stars and black holes. Together with new experimental forefront
facilities like ISAC, ORLaND and RIA, these detectors provide direct,
quantitative physical insight into nucleosynthesis, supernova dynamics,
accreting compact objects, cosmic-ray acceleration, and pair-production in high
energy sources which reinforce the urgent need for a strong and continuous
feedback from nuclear and particle theory and theoretical astrophysics. In my
lectures, I shall concentrate on three selected topics, which range from the
behavior of superdense stellar matter, to general relativistic stellar models,
to strange quark stars and possible signals of quark matter in neutron stars.
