صورة اليوم الفلکیة
Image Credit:
Pierre Konzelmann
Explanation:
What powers this unusual nebula?
CTB 1 is the expanding gas shell that was left when a massive star toward the constellation of Cassiopeia
exploded about 10,000 years ago.
The star likely detonated when it ran out of elements, near its core, that could create
stabilizing pressure with
nuclear fusion.
The resulting
supernova remnant, nicknamed the Medulla Nebula for its
brain-like shape, still glows in
visible light
because of the heat generated by its collision with confining
interstellar gas.
Why
the nebula also glows in
X-ray light, though,
remains a topic of research.
One hypothesis holds that an energetic
pulsar
was created and powers the nebula with a fast outwardly moving wind.
Following this lead, a pulsar was
found in
radio waves
that appears to have
been expelled by the
supernova explosion
at over 1000 kilometers per second.
Although the Medulla Nebula appears as large as a
full moon,
it is so faint that it took 84-hours of exposure with
a small telescope in
Texas,
USA, to create the
featured image.