A
supernova
that
appeared
in
1181
has
been
linked
to
the
Pa
30
nebula
giving
us
a
rare
“zombie
star.”
This
discovery
raises
new
questions
about
how
these
celestial
events
unfold.
Advanced
imaging
techniques
from
the
W.M.
Keck
Observatory
uncovered
unusual
filaments
expanding
from
the
core
of
this
supernova
remnant.
The
supernova,
recorded
as
SN
1181,
was
observed
near
the
Cassiopeia
constellation
and
shone
for
six
months
before
fading.
It
is
one
of
the
few
pre-telescope
supernovae
documented
in
history.
For
centuries,
SN
1181
was
considered
an
“orphan”
because
no
visible
celestial
bodies
were
connected
to
it.
However,
in
2021,
scientists
linked
its
remnant
to
the
Pa
30
nebula,
which
was
first
discovered
in
2013
through
citizen
science
efforts.
The
Zombie
Star
At
the
heart
of
the
Pa
30
nebula
is
the
“zombie
star,”
a
remnant
of
the
original
explosion.
This
star
survived
a
thermonuclear
explosion
on
a
white
dwarf,
which
typically
would
have
been
destroyed.
This
partial
explosion
is
classified
as
a
Type
Iax
supernova.
The
team
of
researchers,
led
by
Tim
Cunningham
and
Ilaria
Caiazzo,
obtained
a
detailed
view
of
the
strange
filaments
that
resemble
dandelion
petals.
Advanced
Imaging
Techniques
Using
the
Keck
Cosmic
Web
Imager
(KCWI),
scientists
first
created
a
3D
map
of
the
nebula.
This
technology
allowed
them
to
measure
the
speed
of
the
filaments,
which
are
expanding
at
about
1,000
kilometers
per
second.
They
noted
that
this
speed
indicates
the
material
has
not
changed
since
the
explosion
in
1181.
New
Insights
into
Supernova
The
research
sheds
light
on
the
asymmetry
of
the
supernova,
indicating
that
the
explosion’s
characteristics
were
unusual.
The
findings
prompt
further
questions
about
the
nature
of
supernovae
and
their
remnants
in
the
universe.