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Science- stars and the universe
solar system
70
Astronomy
8th Grade
10/24/2012

Additional Astronomy Flashcards

 


 

Cards

Term
where do stars start?
Definition
nebula, which is a large cloud of gas and dust
Term
How are stars born?
Definition
material in the nebula begins to collapse because of gravity, the increased concentration leads to increased pressure, the increased temp. causes light to be given off
Term
protostar
Definition
a baby star
Term
what temp. does nuclear fusion start at?
Definition
10 mil celcius
Term
what part of the HR diagram is a young star in
Definition
main sequence
Term
What does the lifespan of a star depend on?
Definition
mass
Term
what is the size of a star based on?
Definition
energy output vs. gravity(mass)
Term
how long is the lifepan of a star if the mass is less than the sun, equal to, and greater than
Definition
masssun- 10 milllion
Term
FITB- the greater the mass the _______ it lives
Definition
shorter
Term
how do stars die?
Definition
Hydrogen fuel is consumed and helium begins fusion, the energy output gets greater than the gravity and the star expands, the helium gets consumed and the energy output becomes less than the gravity, the star shrinks and gives off radative energy, finally the gravity cannot control the energy output so the star explodes
Term
what was the galatic red shift?
Definition
edwin hubble, analysis of spectra from galaxies indicated that it is shifted towards the red end of the visible spectra
Term
FITB- the galactic red shift caused by _________
Definition
the Doppler effect
Term
doppler effect
Definition
apparent change in frequency of light due to relative motion of an object
Term
FITB- greater the shift the _______ the galaxies are moving, the further away the galaxy, the ______ the galaxy is moving
Definition
faster
Term
cosmic background radiation
Definition
energy leftover from the big bang, discovered by accident, proof of big bang
Term
FITB- objects that make up substances are ______ than the substances they compose
Definition
older
Term
timeline of earth, old to oldest
Definition
earth->rocks->mineral->elements->atoms->particles that compose atoms->force that hold these particles together
Term
nuclear force
Definition
force that holds together the nucleaus of an atom
Term
gravitational force
Definition
force that attracts all objects in space to each other
Term
electromagnetic force?
Definition
the force that holds atoms together
Term
FITB- looking out into space allows us to look _____ into time
Definition
back
Term
FITB- the farthest quasars are _____ billion LY's away
Definition
13
Term
how old is the universe
Definition
13.7 billion years old
Term
big bang theory
Definition
universe began as a single point, becomes unstable, begins to expand and is filled w energy and is very hot, universe expands and begins to cool, fundamental forms of physics-elementary particles-and-fundamental elements form, denser regions of gas begin to collapse to form earliest galaxy
Term
the big crunch theory
Definition
gravitional force stops universe expansion and reverses the process
Term
the big freeze theory
Definition
expansion continues until universe is cold, matter decays and black holes evaporate
Term
balance theory
Definition
expansion would stop and the universe would be cold, atter decays and black holes evaporate
Term
light year
Definition
distance that light travels in a year, at a velocity of 186,000 miles per a second
Term
what is the closest star to earth?
Definition
Proxima Centauri and it is 4.2 ly's away
Term
FITB- ______ is the brightest star (8.6 LY's away)
Definition
Sirius
Term
FITB- ______ is the north star (678 LY's away)
Definition
Polaris
Term
FITB- _____ is 518 LY's away and ______ is 900, they are the brightest stars in the constellation Orion
Definition
Betelgeuse is 518, Rigel is 900
Term
What is the distance from the sun to the center of our galaxy? across our galaxy? closest galaxy?
Definition
27,000 LY's to center, 100,000 Ly's across, and 2.9 mil LY's to the Andromeda Galaxy
Term
stellar parallax
Definition
apparent change when you look at an object from different positions
Term
what are the 5 types of stars based on size? smallest to largest
Definition
neutron star, white dwarf, main sequence, red giant, supergiant
Term
FITB- blue stars are _______ than red stars
Definition
hotter, 50,000 celcius compared to 3,000 celcius
Term
apparent brightness
Definition
brightness of object as seen from earth, small numbers are bright while large numbers are dim
Term
absolute magnitude
Definition
brightness of an object with all objects same distance from earth
Term
milky way galaxy
Definition
home of our solar system, 200 billion stars at least and there planets including thousands of clusters and nebulae
Term
FITB- multiple star systems have ____ or more stars
Definition
2
Term
eclipsing binary system
Definition
the larger star passes behing smaller star, dimming the brightest of the larger star
Term
what are the types of multiple star systems
Definition
binary, eclipsing binary, and triple
Term
star clusters
Definition
large group of stars formed in same part of same nebula
Term
what are open clusters compared to globular clusters?
Definition
open- loose and disorganzied group of about 1,000 stars, consists of bright supergiants and gas and dust

globular- millions of older stars, round and densely packed
Term
a galaxy is a huge group of what?
Definition
stars, star systems, star clusters, gas and dust
Term
FITB- many galaxies have ___________ at the center
Definition
black holes
Term
FITB- the three types of galaxies are _____, _____, and ______
Definition
spiral-mixture of young stars and dust(in spiral arms) and older stars(in center of galaxy)
elliptical- oval or round shaped, billions of old stars only, no gas or dust
irregular-contains young stars and gas/dust, near larger galaxies, the gravitation pull distorts the small galaxy
Term
galaxy clusters
Definition
groups of galaxies in the same part of the universe
Term
FITB- the milky way galaxy is part of a _____ group(50 or so galaxies) which is part of the ______________(100 or so galaxies)
Definition
local group, virgo super cluster
Term
quasars
Definition
very bright center of some distant galaxies, due to presense at center of young galaxies
Term
FITB- light can be ______, ______, or ______
Definition
reflected or absorbed or transmitted
Term
what is opaque?
Definition
can not be seen through, reflected or absorbed
Term
what is transparent?
Definition
seen clearly
Term
what is translucent?
Definition
cannot be seen clearly
Term
what is regular reflection?
Definition
angle of incidence is equal to angle of reflection
Term
diffuse reflection
Definition
angle of incidence is not equal to angle of reflection
Term
flat mirror
Definition
wall mirror, image same size
Term
concave mirror
Definition
inward curve, reflects light rays to a point(focal point), size varies, magnifies and focuses
Term
convex mirror
Definition
outward curve, spreads light rays outward, image size smaller
Term
lens
Definition
cause light rays to be refracted
Term
refraction
Definition
bending of light rate due to change in medium(substance that the light travels through)
Term
concave lens
Definition
inward curved, thicker at edges than middle, image smaller, spreads light rays outward
Term
convex lens
Definition
outward curved, thicker at middle than edges, image varies, reflects light rays to a point(focal point)
Term
telescope
Definition
used for collection of lights
Term
refracting telescope
Definition
series of convex lenses to collect visible light
Term
reflecting telescope
Definition
uses mirror(concave and flat) and an eyepiece(convex) to collect visible light
Term
radio telescope
Definition
concave surfaces collect radio signals from deep space
Term
electromagnetic spectrum
Definition
range of wavelengths of light
Term
spectrographs
Definition
breaking down visible spectrum into wavelengths of light that compose the substance
Term
spectral analysis
Definition
technique used to compare know spectra to light from stars, determines composition and temp of stars
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