Astronomy 84 Flashcards

Terms Definitions
heliocentric
sun-centered
Heliocentric scientist
Copernicus
coupled devices (CCD)
...
8 times
black holes
intensity
energy received per second
Doppler
Discovered the Doppler Effect
Long Wavelengths mean:
Low energy
first quarter moon rises
at noon
Saturn's Moon
Titan, thick nitrogen-rich atmosphere
supernovae
death of stars, massive explosions
Stars phases
1.Nebuela 2.Main Sqnce 3.Red/supergiant 3.White dwarf, or Supernova
1st Quarter
rise: noon; set: midnight
magellanic clouds
nearest galaxy to our own
canopus
Alpha Carina; 2nd brightest normal star in the sky (apparent brightness); horizontal branch star; brighter than sirius in luminosity
accretion
the sticking together of particles through electrostatic forces
Sun
What star is closest to us?
white dwarf
dead core of a sun
lenticular galaxies
intermediate between E7 ellipticals and Sa spirals
- S0 and SB0 galaxies
quasar
an enormously bright, distant galaxy with a giant black hole at its center
inner planets (terrestrial)
mercury, venus, earth, mars
-warmer
-land
aphelion
planets farthest distance from the sun
spyglass
toy invented by a dutch glassmaker that changed astronomy
luminosity
The quality of giving or radiating light.
photon
visible light emitted during a single donword transition
In one year, Earth completes 365 revolutions...true or false?
False
eclipse
two objects of approximately the same angular size cross in front of each other
Orbit
Curved path of a satellite that results from a combination of the satellite's forward movement and the gravitational pull of Earth
When a gas is compressed, it:
Heats up.
decreases
on an H-R diagram, temperature ___ left to right (based on OBAFGKM)
Nova
A nova is a catacysmic nuclear explosion caused by the accreation of hydrogen onto the surface of a white dwarf star.
Autumnal Equinox
occurs around September 23-marks the beginning of Fall in the Northern Hemisphere
continuous
This spectrum is caused by an incandescent light and shows all colors of the rainbow.
Nebula
an immense cloud of gas (mainly hydrogen) and dust in interstellar space
rovers
Some probes have small robots that move around on the surface.
light
is a form of electromagnetic energy from the basic white light
Comet
Composed of dust, rock particles, and frozen gases and has a nucleus, coma, and tail
farther away a star is
shift is less
In a collision, an object experiences _______ for a given amount of time, resulting in _____ undergoing change in velocity, i.e. change in momentum
force, mass
Electromagnetic Spectrum
a continuum depicting the range of electromagnetic radiation, with the longest wavelength at one end and shortest at the other
Retrograde
Each planet orbits the Sun at a different velocity causing earth to catch up and then pass planets further from the Sun causing the illusion that the planet is moving backwards. Planets closer to the Sun orbit faster. The planet does retrograde but due to the two bodies orbital motions.
When convection becomes unstable and outer layers of star float away:
planetary nebula forms.
kuiper belt
a doughnut shaped region that extends beyond Neptune to about 100 times Earth's distance from the sun
Pluto's downfall as a planet
Sweeping its orbit clean
Gravity
What force pulls the moon and Earth toward each other?
# of earths that fit in sun
1 million
meteoroids
A chunk of rock or dust in space.
what is dark energy
energy associated with repulisve gracity
Sirius
brightest star in our sky, 8 light years away
noon
When the first quarter moon rises and the third quarter moon sets
Planet
Any of the 9 heavenly bodies revolving around the sun.
EM SPECTRUM:
All the FREQUENCIES & WAVELENGTHS of EM Radiation
gravity waves
wave in the fabric of spacetime emitted by accelerating masses
Stars that are visible in the local sky on any clear night of the year, at any time of the night, are called _________.
circumpolar
prograde motion
the planets seem to drift forward, west to east
Plate tectonics
The movement of the Earth's crustal plates riding on top of the mantle.
heavy bombardment
The period of heavy bombardment was the era during the formation of the Solar System when the vast numbers of planetesimals in the young Solar System were colliding with each other and with the proto-planetary bodies. This occurred from the beginning of the Solar System till about 4 billion years ago.
meteor
streak of light that we see across the night sky.
Venus and Earth
What are the sister planets with relatively the same size, mass and density?
absorption line
a dark line in a continuous spectrum created when photons of a certain energy are absorbed by atoms or molecules
nucleus
a part of the cell containing DNA and RNA and responsible for growth and reproduction
ALBERT EINSTEIN (1879-1955)
Special & General Theory of Relativity Cosmological Constant.
dark energy
a mysterious new force that is causing hte expansion of the universe to accelerate
Ecliptic
The path of the sun on the celestial sphere
standard candles
-We believe that all these white dwarf supernova
explosions are very similar, since they are all
initiated in the same way, by a gradual approach
to the largest mass white dwarf possible, and
then beyond that, producing the explosion.
-For this reason, we believe that with only small
variations, the luminosities of these white dwarf
supernova outbursts are all the same, so that we
can use them as "standard candles" to obtain
distances to far away galaxies.
Light year
The distance traveled by light in a year.
Red shift
(astronomy) a shift in the spectra of distant galaxies toward longer wavelengths
interstellar bubble
The surface of a bubble is an expanding shell of hot, ionized gas driven by stellar winds or supernovae; inside the bubble, the gas is very hot and has very low density.
Elongation
The angle between the Sun and a planet viewed from Earth
What is the speed equation?
speed = distance / time
Terrestrial planets
Close to the sun and mostly solid and are high in density
Partial eclipse
A solar or lunar eclipse in which the eclipsed object does not appear completely covered
This planet is the brightest in our solar system
What is Venus?
Isaac Newton
The Laws of Gravity - all objects in the universe attract each other through gravitational force
Newtons law of gravity
Everything with mass has gravity & more mass=more gravity
North Star
The Earth is tilted on its axis with the North Pole always pointing toward the
era of atoms
The era of the universe lasting from about 500,00 years to about 1 billion years after the Big Bang during which it was cool enough for neutral atoms to form.
Kepler's first law
planets orbit in ellipses, sun at one focus, (two foci) other focus was empty
Stefan-Boltzman Law
A formula from which the rate at which a blackbody radiates energy can be computed; the total rate of energy emission from a unit area of a blackbody is proportional to the fourth power of its absolute temperature
Properties of light
light can be a wave and a particle. they have a wavelength and a frequency.
the percentage composition of interstellar gas (dont type %)
75 hydrogen, 24 helium, and 1 dust
which phase of the moon is first to be seen
waxing cresent
Further pressure from gravity squeezes past the point where neutrons can collapse to form...
a black hole (> 3 solar masses)
What is the universe composed of
mostly empty space, also energy and matter
meteorites: difference from meteors, types, from moon and mars
-meteorite is a rock from space that falls thru earth's atmosphere, meteor is the trail left by a meteorite
-types: primitive-unchanged since they formed 4.6 bill yrs ago, processed-younger, have experienced changes like volcanism
-some meteorites come from the moon and mars- are ejected by meteorite collisions
light minutes to light hours
The distance to bodies in the solar system are a few
light minutes to light hours
light seconds to light hours
Modern science traces its roots to the
GREEKS who first created models and never referred to supernatural reasons
mercury, venus, earth, mars, jupiter, saturn, uranus, neptune, pluto
lis the planets in order starting from the sun. my very energetic mother just served us nine pizzas
Small deviations in a planet's orbital motion
D. imply the gravitational influence of a nearby massive body
Small deviations in a planet's orbital motion
A. show we don't fully understand gravitational forces yet
B. indicate the presence of an extensive atmosphere
C. indicate the presence of a powerful magnetic field
D. imply the gravitational influence of a nearby massive body
E. show the planet's orbit is not stable
it is a 50 billion ton explosion
how big is coronal mass ejection in terms of how much does it explode?
Most black holes have been seen by radiation in this part of the spectrum?
X-ray.Yet they are NOT x-ray bursters because bursters require accumulation of matter on the surface (not possible in a black hole)
What is the estimated mass of the black hole in the core of M87?
3 billion times the mass of the sun
Each of the following lists two facts. Which pair of facts can be used with Newton's version of Kepler's third law to determine the mass of the Sun?
Earth is 150 million km from the Sun and orbits the Sun in one year.
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