Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Iota Herculis is a fourth-magnitude star in the constellation Hercules. The luminary shares an etymological similarity with the star Rigel in the constellation of Orion, as both stars refer to one of the feet of each mythological hero. Iota Herculis is a B-type subgiant star that is at the end of its hydrogen fusion stage. With a stellar classification B3IV, it is considerably larger than the Sun, having a mass that is 6.5 times solar and a radius 5.3 times. Though its apparent magnitude is only 3.79, it is 2,500 times more luminous than the Sun, yielding an absolute magnitude of -2.11, brighter in fact than the most of the hot B stars in the Pleiades open star cluster.