Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Delta Boötis is a binary star in the constellation Boötes. It is approximately 117 light years from Earth. The primary component is a yellow G-type giant with an apparent magnitude of +3.46. Its companion is a yellow G-type main sequence dwarf with an apparent magnitude of +8.7. Sometimes, this star is called by the name Princeps, meaning prince or prime in Latin. About 3800 AU apart, the two take about 120,000 years to orbit each other.