Local Interstellar Matter: The Apex Cloud

Several nearby individual low column density interstellar cloudlets have been identified based on kinematical features evident in high-resolution CaII observations near the Sun. One of these cloudlets, the Aquila-Ophiuchus'' cloud, is within 5 pc of the Sun and located in the solar apex direction. The velocity vector of this Apex Cloud is reevaluated and components at this velocity are found towards 17 stars with distances 1--60 pc, and located primarily in the galactic center hemisphere. The Apex Cloud is the most likely candidate for the next’’ interstellar cloud to be encountered by the Sun.