Helix Nebula
The Helix Nebula (NGC 7293) — the nearest bright planetary nebula, about 655 light-years away in Aquarius: the glowing shells of gas a dying Sun-like star has puffed off, lit by the searing white-dwarf core it left behind. This is the fate that awaits our own Sun in roughly five billion years — not a violent supernova like the Crab, but a quiet shedding of its outer layers. Its ring-within-a-ring form, seen almost pole-on, earned it the nickname 'the Eye of God'.
Science
Physical
- Type
- Planetary nebula (a Sun-like star's ejected envelope + white-dwarf core)
- Distance
- ~655 light-years
- Size
- ~2.9 light-year radius (~25 arcmin on the sky)
- Central star
- A hot white dwarf (WD 2226-210) — ~0.68 M☉, ~120,000 K
- Age
- ~10,600 years since the gas was shed
How we know
- Note
- The image is a REAL Hubble + Cerro Tololo composite (NASA/ESA, C.R. O'Dell; public domain), shown as a camera-facing billboard at the nebula's real position — presented as seen from Earth. 'Planetary nebula' is a historical misnomer: it marks a dying Sun-like star, and has nothing to do with planets.
Discovery & history
- Name
- NGC 7293 in the New General Catalogue (Caldwell 63); a 'planetary' nebula for its round, planet-like telescopic disc — a historical misnomer, nothing to do with planets.
Discovered by Karl Ludwig Harding before 1824. Its true nature — a Sun-like star in its death throes, not a distant galaxy — became clear only in the 20th century; Hubble and ESO have since resolved thousands of comet-like gas knots, each pointing away from the scorching central star.
Images
Images from open archives · credit shown per image