eagle nebula movie HR Diagram Oh yeah youre

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-Rock. STARS like our Sun) u 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 rise u 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 u Later in life, stars become Red Giants • Star has converted all Hydrogen into Helium. Where is it on H-R diagram? u Temp. drops, size increases

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

Outer Shell Ejection u u 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

IC-418 Eskimo Nebula Ant nebula

NGC 7027 NGC 7662 Hourglass nebula Helix nebula

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

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

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

What about Contract-Rock. STARS? (Massive stars) Protostar u Main Sequence u Super Red Giant u Variable Star u Supernova u Pulsar (Neutron Star) u Black Hole u

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

Yeah…they’re pretty bright…

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

We are all stardust…. man. . u u 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….

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

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

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

Supernova recap u Supernova recap via Lite-Brite