Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
interstellar cloud
|
cloud compresses, gravity takes over, compressing the cloud further
densest parts of cloud become garvitationally unstable and fragmentation occurs; radiation cannot escape; temp and pressure increase pushes away light materials |
|
|
eagel nebula
|
hot stars give off energy which evaporate dust and push gas away
EGGs:denser regions of gas and dust will contract under their own gravity, forming protostars |
|
|
protostar
|
=collapsing cloud of gas and dust which will eventually become a star
|
|
|
condensation of solids
|
close to sun: metal oxides and pure metals
farther out: silicates and rocky materials outer regions: ices (water, methane and ammonia) |
|
|
planetesimals
|
from thru 1 of 2 methods:
1. condensation- atoms of gas hit dust grains and stick, adding mass to the particle 2. accretion- solid particles collide and stick to one another form faster thru accretion then condensation |
|
|
clearing of solar nebula
|
1.radiation pressure: light from sun exerted pressure on particles, pushing them further out of solar system
2.solar wind-flow of atoms from sun's upper atmosphere pushed particles out of solar system 3. as planets moved thru orbits, swept up material in their path 4. gravitational effects due to massive planets ejected particles |
|
|
T Tauri Stars
|
protostars which exhibit violent surface activity/ strong stellar winds
energy in form of jets ejected perpendicular to the disk |
|
|
star formation
|
as gas/dust clouds collapse, particles collide more frequently, increasing temp.
gas becomes ionized when core is hot/dense enough, nuclear reactions occur radiation energy halts gravitational collapse and star is born |
|
|
hydrostatic equilibrium
|
gravity pushes in on star but pressure is pushing outward, balancing star ->radiation created
more mass=more gravity pushing in=more radiation needed to resist brown dwarfs: failed stars, low mass |
|
|
why extrasolar planets have high mass and low period
|
high mass: greater wobble produced by star's motion
low period: shorter period over which wobble occurs |
|
|
sun properties
|
most hydrogen, some helium
completely gaseous generate energy at core strong magnetic field |
|
|
layers
|
corona: outer atmosphere
chromosphere: lower atmosphere photosphere: visible surface |
|
|
granulation
|
size of texas, 10-20 minutes
brighter center, hotter center than edge, center blueshifted convection: circulation in fluid driven by heat |
|
|
zeeman effect
|
sunspots show splitting of emission lines,due to magnetic field
|
|
|
prominences
|
hot ionized gas trapped in magnetic fields
|
