Greetings and welcome to the
Introduction to Astronomy.
One of the things that I like
to do in each of my introductory
astronomy classes is to begin
the class with the astronomy
picture of the day from
the NASA website that is
APOD.NASA.GOV/APOD.
And today's picture for
November the 25th of 2019.
Well, it is titled NGC
6995: The Bat Nebula.
So what do we see here?
Well, perhaps you can see
the bat in these gases
out in space in these nebula.
And this is actually
part of the Veil Nebula.
And we've looked at that before
the Veil Nebula is a supernova
remnant.
This is just a portion
of the Veil Nebula.
The Veil Nebula is a
tremendously large supernova
remnant that would span
many full moons across.
And this is just one
small section of that.
And in fact, because
it is so large
it is often seen as
a different nebulae.
So this is one of
the ones that we see.
But there are also other nebulae
that are also part of this.
And one that is mentioned
is the Witch's Broom Nebula
that we often look at around
Halloween time, which we see,
which is also another
part of the veil nebula.
Now this is, again, the remnant
of a star that exploded.
So this is just a
piece of that material
that we're seeing here is
material that is expanding out
into space and has been doing
so for thousands of years
since this since this star was
seen to explode here on earth.
And we're seeing still
even after that long time.
The turbulent nature
of this long filaments
of material and
shock material as it
strikes in through the
interstellar medium.
So the intense energy
of that supernova
can still be seen today long,
long after the supernova
itself was done.
Now the image here is
looking at the emission
of several different atoms.
And in fact red is the
hydrogen gas shown there.
And of course, hydrogen
makes up the vast majority
of the material within
this supernova remnant
as it does with just about
everything else in astronomy.
Hydrogen composes 90% of
the atoms in the universe.
So most likely if
you pick out an atom.
It is going to be
a hydrogen atom
But we can also look
at other atoms here.
And in fact, the
blues are looking
at the emission of oxygen
and nitrogen atoms oxygen
and nitrogen atoms are
formed within stars
and are then expelled
back out into space.
So the layers of the star
that had formed these
could have been expelled
them back out into space.
And that's what happens
with supernovae remnants.
They enrich the material formed
from the interstellar medium.
So they add more of these
heavy elements things
that are other than
hydrogen and helium.
So that new generations of stars
that form billions of years
from now can form from
this enriched material,
and it is because
of things like this
that the earth exists the
original big bang only created
hydrogen and helium so a planet
like earth with lots of silicon
and iron would be
unable to form and life
needing carbon and oxygen
would also not be able to form.
However, after many
generations of supernovae
expelling this type of
material out into the universe
we have then been able to
form planets like the earth
and be able to form life.
So all of those heavier
elements, everything other
than hydrogen or
helium whether on earth
or in our bodies is actually
comes from something like this.
So that was our picture of
the day for November the 25th
of 2019.
It was titled NGC
6995: The Bat Nebula.
We'll be back again tomorrow
for the next picture previewed
to be Galaxy Sized Ring.
So we'll see what that
is about tomorrow.
And until then have a
great day, everyone.
And I will see you in class.
