Sh2 119
Clamshell Nebula
The Clamshell Nebula, or Sh2-119, is a large, faint emission nebula located roughly 2,200 light-years away in the constellation Cygnus, near the North America Nebula. Spanning a significant area, it is ionised by the 5th magnitude star 68 Cygni, which creates its distinctive, partially ionised structure.
Key Characteristics
Distance and Size
It is estimated to be approximately 2,200 light-years way from Earth. The nebula spans a vast region of the sky, often described as being as large as the entire Veil Nebula complex.
Structure:
Its nickname comes from its distinctive shape, which resembles two open shells arranged to the east and west of its central star. The southern portion is notable for its intricate dark filaments, Bok globules, and dust lanes.
Ionising Source:
The nebula’s glow is primarily powered by 68 Cygni, a hot, massive blue-white O-type star (magnitude 5) located near its center.
Location:
Situated roughly 2–3 degrees east of the more famous North America Nebula (NGC 7000) and is often overlooked due to its lower surface brightness.