Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. HW Virginis, abbreviated HW Vir, is an eclipsing binary system (of the Algol type) approximately 590 light-years away in the constellation of Virgo. The system comprises an eclipsing B-type subdwarf star and red dwarf star. The two stars orbit each other every 0.116795 days. In addition, the system has two substellar companions in orbit around the binary: the inner companion HW Virginis c has a mass at least 8.47 times the mass of Jupiter and takes just over 9 years to complete an orbit.