It's easy to get lost following the intricate filaments in this
image of faint
supernova remnant Simeis 147.
Seen towards the constellation
it covers nearly 3 degrees (6
full moons) on the sky corresponding to a width of 150 light-years at
the stellar debris cloud's estimated distance of 3,000 light-years.
The color composite image includes eight hours of exposure time
with an H-alpha filter, transmiting only
the light from recombining hydrogen atoms in the expanding
nebulosity and tracing the regions of
shocked, glowing gas.
This supernova remnant has an apparent age of about 100,000
years - meaning light from the massive stellar explosion first
reached Earth 100,000 years ago - but this expanding remnant is not the only
The cosmic catastrophe also left behind
a spinning neutron star or pulsar,
that remains of the original star's core.