APOD: 2023 April 2 Б M57: The Ring Nebula from Hubble
Explanation:
It was noticed hundreds of years ago by stargazers who
could not understand its unusual shape.
It looked like a ring on the sky.
Except for the rings
of Saturn,
the Ring
Nebula (M57) may be the most famous celestial circle.
We now know what it is, and that its
iconic shape is
due to our lucky perspective.
The recent mapping of the
expanding nebula's
3-D structure, based in part on
this clear Hubble image,indicates that
the nebula is a relatively dense, donut-like ring wrapped
around the middle of an (American)
football-shaped cloud of glowing gas.
Our view from
planet Earth looks down the long axis of the football,
face-on to the ring.
Of course, in this well-studied example of a
planetary nebula, the glowing material
does not come from planets.
Instead, the gaseous shroud represents outer layers expelled
from the dying,
once
sun-like star, now a tiny pinprick of light
seen at the nebula's center.
Intense ultraviolet light from the hot central star
ionizes atoms in the gas.
The
Ring Nebula is about one
light-year
across and 2,500 light-years away.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
