eagle nebula movie

H-R Diagram (Oh yeah, you’re gonna see it again!)

Interstellar cloud of gas and dust – Birthplaces of stars!

Star Birth (Indie-RockSTARS like our Sun)  Protostar – Stage 1. Gas and dust collapses on itself by gravity, balanced by outward gas pressure. Inward gas pressure trying to escape, causing internal temp. & press. to riseInward gas pressure trying to escape, causing internal temp. & press. to rise  This causes nuclear fusion to begin!

Star Birth

Main Sequence Fully developed star (like our sun) -most of stars lifetime spent in this stage

Senior Citizen Stars  Later in life, stars become Red Giants Star has converted all Hydrogen into Helium. Where is it on H-R diagram?Star has converted all Hydrogen into Helium. Where is it on H-R diagram?  Temp. drops, size increases

Senior Citizen Stars  Variable Stars – expand and contract, grow bright and fade. Over a period of 1 – 70 daysOver a period of 1 – 70 days  Quick for a star that lasts ~10 billion years!

Outer Shell Ejection  Later in life, a star will eject the outer shell of Hydrogen, leaving the Helium behind in the core.  This fast traveling Hydrogen gas is called a Planetary nebula

Eskimo Nebula IC-418 Ant nebula

NGC 7662NGC 7027 Hourglass nebula Helix nebula

Hi-ho, Hi-ho, It’s off to work….  After it’s shell is gone, all that is left is a layer of Helium, and a core of denser Carbon. Gravity pulls star inwardsGravity pulls star inwards  Results in very small, very dense dying star, a White Dwarf Low luminosity, low temp.Low luminosity, low temp.

R.I.P. Indie-RockSTAR  Eventually, White Dwarf cools further, turns red, and dies.  It is now called a Black (Brown) Dwarf

Sun-like Life Cycle  Protostar  Main Sequence  Red Giant  Variable Star  Planetary Nebula (Ejection)  White Dwarf  Black Dwarf

What about Contract-RockSTARS? (Massive stars)  Protostar  Main Sequence  Super Red Giant  Variable Star  Supernova  Pulsar (Neutron Star)  Black Hole

Supernova  Gigantic stellar explosion  Carbon core temp. rises to 600 million K! That’s hotThat’s hot  Carbon fuses in the core, produces Iron Fusion stopsFusion stops  Iron doesn’t fuse

Yeah…they’re pretty bright…

Crab Nebula  First noted by Chinese Astronomers in 1054 A supernova remnant!A supernova remnant!

We are all stardust….man..  Supernova ejection cloud travels away quickly, and the intense heat, pressure, electrons, etc. cause all the heavier elements to form in the universe.  So, really, we’re all formed from the remains of stars! My head hurts now….My head hurts now….

Pulsars (Neutron Stars)  After a star explodes, sometimes only neutrons are left (Guess where the name “Neutron Stars” came from?)  Also called Pulsars because they emit radio waves with incredible regularity.  Appear to be rapidly rotating neutron star

Pulsar The crab pulsarA slower pulsar Yup, same one they saw in 1054!

Black Holes  Some REALLY big stars can continue to collapse after the pulsar stage to become super dense areas of space known as black holes  Simply a point in space where gravity concentrates a large mass into a very, very small area

Black Holes  Surface of black holes, the point at which no light can escape, is called the Event Horizon  Spot in the center, in theory, is called the Singularity

Black Holes  Schwarzschild Radius is the theoretical radius at which a spherical body becomes a black hole.  R = 2GM/c^2 G=gravitation constant M=mass c=speed of lightG=gravitation constant M=mass c=speed of light  Sun = 2 miles  Earth = 1 cm (.4 inch)

Supernova recap  Supernova recap via Lite-Brite via Lite-Britevia Lite-Brite