Institute for Advanced Study Informal Astrophysics Seminar - ADDED

ABSTRACT: Many irregular astrophysical systems and phenomena are not so rare, and in fact constitute a large fraction of all astrophysical systems. I will discuss several such riregular systems, ranging from irregular moons in the Solar-system, re-captured runway planets, and planetary systems in evolved binaries, up to stellar collisions and strange supernovae. I wil likely not have the time to discuss all of the following, but I will try to focus on few of them, and briefly mention the rest. The observational discovery of new types of thermonuclear supernovae explosions and suggest novel explanations for their origin. Such supernovae potentially have major implications; some can produce unique type of iron-core white dwarfs (WDs), provide a mechanism for WD natal kicks, never explored before. Others may explain the origin of a large fraction of the calcium in the universe, and may be important for the productions of positrons and 511 kev emission. On the dynamical sides, I will suggest a novel origin for irregular moons formation, linking them to current understanding of extrasolar systems. I will also explore how mass loss in stellar and stellar cluster systems can produce unique planetary and stellar systems, and allow planetary and stellar exchanges between different systems, an may induce physical collisions between the systems components.