05- Star Formation, and Existence Span Flashcards
A theory that explains the origin and organization of stars. Rotating cloud/gas gravitationally collapses and flattens.
Solar Nebula Theory
low-density clouds of gas and dust among starts (sun composition). It’s made up of single atoms: 75% hydrogen, 25% helium.
Interstellar Medium (ISM)
a “cloud” typically seen as emission, reflection, or dark interstellar reddening.
Nebula
part of the nebula. It’s pushed by warmer currents and it’s so dark and dense that light won’t shine through it.
Dense Cloud
Stars seen through clouds are redder because dust scatters blue light. Same reason we see a very red sun during smokey skies
Interstellar Reddening
Stars have buddies! (unlike our star). A stable star group, held by combined gravity orbiting common center mass
Star Cluster
A group of stars formed together BUT is not gravitationally bound, so they drift apart.
Stellar Association
small dark cloud approximately 1ly that contains 10-1000 solar masses of gas and is able to form a star.
Bok Globules
First step of solar nebula theory. A sudden change of pressure which disrupts and compresses the cloud
Shock Wave
Second step of solar nebula theory (after a disk is formed). As gas is added, a warmed ball becomes destined to become a star and is buried deep in dusty cloud
Protostar
The third step of solar nebula theory. Small flickering nebula vary in brightness from gas jets off prostar from opposite directions.
Herbig-Haro Object
The fourth step of solar nebula theory. It is a teenager star that has a strong magnetic dynamo, a fast spin, wind/polar jets push out debris
T Tauri Star
Final step of the solar nebula theory!!
A STAR is BORN!
table of numbers, a mathematical model of laws of stellar structure.
Stellar Model
- Conservation of Mass
- Conservation of Energy
- Hydrostatic Equilibrium
- Energy Transport
Laws of Stellar Structure.
mass = sum of shell masses. Mass is conserved because mass is neither created nor destroyed.
Law of Conservation of Mass
Total luminosity = sum energy generated in all layers in each shell.
Law of Conservation of Energy
Weight of each layer is balanced by pressure in each layer. Gravity pushes in as energy pushes out.
Law of Hydrostatic Equilibrium
Energy moves from hot to cool regions by conduction, radiation, and convection.
Law of Energy Transport
the minimum energy to take atoms apart
Nuclear Fission
Energy needed to build atoms. Symbolized by scientific formula: 4x1H = 1x4HE + E
Nuclear Fusion
Failed stars that cannot sustain fusion. 10 times of earth’s diameter which is about the size of Jupiter.
Brown Dwarfs
start of star existence span mass-luminosity relation.
Zero-Age Sequence (ZAMS)
For lower masses than the sun. The first reaction is deuterium (heavy hydrogen) which emits positron (antimatter electron) and neutrino (neutral, mass)
Proton-Porton-Chain Reaction
