The document summarizes the life cycle of stars from their birth in nebulae through their evolution into red giants, white dwarfs, neutron stars, or black holes. It explains that stars produce light through nuclear fusion, where hydrogen fuses into helium. Nebulae are large clouds of dust and gas where stars are born as gravity causes material to collapse and form protostars at the center.

1. The lifecycle of a STAR!!!
get ready to take notes!

2. The Life of a Star…
1. Protostar- born in a
nebula, gases come
together and begin
nuclear fusion.
2. Star- the phase where
the star burns fuel. The
more massive the star,
the shorter it’s lifespan!
3. Red giant/supergiantwhen stars run out of
fuel, the outside
expands and the inside
contracts.
4. White Dwarf-One
possible outcome. The
remainder of a star,
after the outer layer
expands away.

3. The Life of a Star…
5. Super Nova- If a star
doesn’t become a white
dwarf, it will supernova
(aka- explode!)
6. Neutron Star- What’s
left after a supernova
(suuuuper dense core)
7. Black Hole- The most
massive pre-supernova
stars may become
black holes after they
supernova. The density
reaches extreme highs
and pulls everything
inward to the point
where light cannot
even escape!

4. How do stars produce light??
Stars emit TONS of energy!!
We can see some of it in the form of visible
light.
When the temperature of a protostar (star
beginning to form) gets hot enough Nuclear
FUSION occurs.

5. How do stars produce light??
 Stars produce light by Nuclear FUSION.
 This is when two atomic nuclei combine to
form a larger nucleus with a higher mass.
 (ex: hydrogen becomes helium)

6. How stars FORM
NebulaA large cloud in space
containing dust,
hydrogen gas, helium
gas and plasma.
*Stars are formed in
nebulae
The space between
stars is called
interstellar space and
it contains mostly gas
and dust. It’s density is
extremely lowapproximately 1 atom
per cubic meter.

7. Components of Nebulae
 The dust in a Nebula is not
like house dust, it’s made
up of much smaller
particles that typically
includes carbon and
silicate molecules

8.  These beautiful regions are called nebula.
They are the formation of gas, dust and
other materials clump together to form
larger masses which attract more matter
and eventually get big enough to form a
star.
 Here are some examples…

9. This picture
was taken from
the Hubble
Telescope, it’s
called “NGC604” and is
located in a
neighbor spiral
galaxy of ours,
2.7 million light
years away
from us.
Photo credit: STSci

10. These are the star
forming “Pillars of
Creation” spotted
by the Hubble
Telescope.
Photo credit: STSci

11.  Many Nebula form from the gravitational
collapse of gas in the interstellar medium
(ISM).
 As the material collapses under it’s own
weight, stars may form in the center.
 Here are some examples…

13. Photo
Credit:
STSci

14.  Some nebula are the result of supernova
explosions (the death of short lived
massive stars.)
 Example…

15. This is the Crab
Nebula in the
Constellation of
Taurus. This
Nebula is
actually visible
with the naked
eye on a clear
night.
Photo Credit: STSci

16.  Some Nebula are called “Dark Nebula”
and seem to be the creepers of the bunch
(if you ask me), they tend to look a little
more scary.
 They are very dense and light has a hard
time passing through (hence, they are
‘dark’)
 Such as…..

17. This is a dark nebula called “Horse Head”
It’s so dense that it obscures light from behind it.
Photo Credit: STSci

18.  And our last beauty for the day:
 Planetary Nebula- These are the gaseous
shells that are ejected as giant stars
transform into white dwarfs.
 Example…

19. Photo Credit: STSci

20. Photo Credit: STSci

21. Photo credit: STSci

22. Super Nova Remnants
 Every once in a while, we get a glimpse
into the beauty that is left behind after the
massive explosion of a super nova (when
a star explodes).

23. Photo Credit: STSci