Eps

Its story

Epsilon Aquilae, known as Deneb al Okab Borealis —«the northern eagle's tail» in its Arabic designation— is an orange giant 155 light-years away that hides an unseen partner. Every 1,271 days the two complete an eccentric orbit, and only the periodic shift of spectral lines betrays the second. The system is also drifting toward the Sun at 46 km/s.