Astronomy Flashcards

Terms Definitions
heliocentric universe
spiral shape
self-luminous celestial object
Radial Motion
Along line-of-sight
Kepler's 3rd Law is
HR diagram
temperature vs. luminosity
How many moons orbit Jupiter?
shape of orbit, elongated oval
lightly coloured convection features about 1000km in diameter seen constantly in the solar photosphere.
the closest galaxy to ours
E=energy, m=mass, c=speed of light
simple magnifying glass with short focal length
Maintain a stable balance between pressure pushing out and gravity pulling in. When the balance is lost, it changes dramatically.
Wien's Law
Hotter objects are bluer....Cooler objects are redder
solar wind
streams of electrically charged particles
almost all stars have hydrogen (60-80%) and the remainder is helium. Other elements could be carbon, oxygen, nitrogen, and neon
globular cluster
tightly bound, roughly spherical collection of hundreds of thousands and sometimes millions od tsars spanning about 50 parsecs. distributed in halos
the doppler shift toward shorter wavelengths of light from an approaching object
an elementary particle carrying a positive electric charge, a component of all atomic nuclei. The number of protons in the nucleus of an atom dictates what type of atom it is.
Heavy elements have ____ melting temperatures and could condense at _____ temps.
Light Year
The distance light travels through space in one year.
Small solid particals that have orbits in the solar system.
The __________ motion of planets is when they appear to move in a reverse direction.
Density of the Satellites:
decreases outward from jupiter
what causes objects to lose orbital energy
Red Shift
stars moving away from the observer
lowest layer of the Sun's atmosphere and the layer that gives off light
what is the strong force between quarks carried by
Electromagnetic spectrum
the complete range of electromagnetic radiation, from radio waves to gamma rays, including visible spectrum. All types of electromagnetic radiation are basically the same phenomenon, differing in only wavelength, but all go the speed of light.
redder<=R, I, V, U, X, G=>bluer
The lighter, outlying regions of a shadow
a region of complete shadow resulting from total obstruction of light
inner, rocks and metal, no rings, solid surfaces
An imaginary great circle on the surface of the earth passing through the north and south poles at right angles to the equator, runs from N to S and divides sky E and W.
The Sun
Not in the Zodiacal Constellation claimed by astrologers due to the Earth's precession.
blackbody radiation
-emitted by hot stuff: composition doesn't matter as much
-smooth spectrum
-Intensity and peak wavelength depend on temperature
black hole
a theoretical massive object, formed at the beginning of the universe or by the gravitational collapse of a star exploding as a supernova, whose gravitational field is so intense that no electromagnetic radiation can escape.
star trails
show movement of stars during the night
the distance light travels in one year-5.9 trillion miles/9.5 trillion km.
light year
occam's razor
the principle of choosing the simplest scientific theory that correctly explains any phenomenon
the study of stars planets moons and other objects in space.
The total energy of the universe is decreasing as energy decreases,
Galileo found ___ that challenged the geocentric worldview.
Jupiter's moons
the explosion of a dying giant or supergiant star
Axis of Rotation
the center around which something rotates
ecliptic plane
the flat plane that Earth's orbital path defines
It revolves around the Sun
Why Earth has seasons
Solar Day
Measured from noon to noon; 24 hours.
superior planet
closer to earth than sun mars, jupiter, saturn, uranus, & neptune
Solar eclipse
the moon interrupts light from the sun
Caloris impact crater
on Mercury;
thought to have nearly blown the planet apart
Fair Test
An experiment that is repeated a minimum of three times.
List four methods for determining distances in astronomy in distance order from the Sun to the edge of the visible universe
Hubble law
Star clusters
What temple in Mexico has windows that were originally lined up with different astronomical events?
First quarter
Half of the moon is illuminated because the angle between the moon, earth, and sun is 90•
a bright red supergiant star in the constellation Orion
baryon number problem
the fact that the universe is matter-dominated, rather than having an equal amount of antimatter as would be expected if the big bang were true.
ptolemy did what for astronomy?
Geocentric model, accurate predictions of planatery motions
the length of a wave from valley to valley or top to top
What is Palimpsest?
large craters that have lost relief from isostatic adjustments
describes the view that the sun is at the center of the solar system
Recessional Velocity
the speed of which galaxies are moving away from the Milky Way
solar system
consists of the sun and all the objects that orbit it: the planets and their moons, the chunks of rock we call asteroids, the balls of ice we call comets, and countless tiny particles of interplanetary dust
nebular theory
theory that the sun and the planets condensed out of a spinning cloud of gas and dust
spirals (s)
made up of blue stars, gas and dust
circumpolar star
A star that always remains above the horizon for a particular latitude.
The universe has been expanding for how many years?
14.7 billion yrs
What is "spin up"?
When acretion occurs and matter falling into the neutron stars spins faster as it moves closer to the center of the star.
Meteor Shower
is a celestial event in which a number of meteors are observed to radiate from one point in the night sky. These meteors are caused by streams of cosmic debris called meteoroids entering Earth's atmosphere at extremely high speeds on parallel trajectories.
Red Giant
A star that expands and cools once it runs out of hydrogen fuel
first energy can be traced back to
the big bang theory
satellite galaxies
more than 45 in all. large and small magellanic clouds
when the earth spins fully,, concluded 24 hours of a day, when the planet spins on its axis
What is a rotation
the time the sun is above / below the horizon an equal amount of time
one billion years ago
how long ago did multicellular life forms appear in the fossil record?
brown dwarf
A star whose mass is too low to ignite nuclear fusion. Heated by contraction. (p. 192)
What is ONE reason that the astronauts' Lunar footprints will probably still look fresh a million years from now?
The Moon has no atmosphere.
Hubble and the Andromeda nebula
thought he discovered 3 novae in M31
realized it was a variable star
It was a cephied variable
Kepler's Second Law
a line that connects the sun and the planet will sweep = areas at = times.
on what side of the moon can u see earth
near side
Kepler's 3rd law states that
there is a relationship between a planet's sidereal period and distance from the sun
Which of the following can NOT be used as observational evidence of interstellar matter?
The clustering of Stars
It takes the moon ______ days to make a complete rotation
27 and a half
What is a waning gibbous?
Amount of light seen from earth is decreasing
Most light is on the left side
discovered as an emission line in the chromosphere during a solar eclipse in 1868
when and how was helium discovered?
The moving plates on the Earth's surface
have boundaries clearly mapped out by the locations of earthquakes and volcanoes
(17) The authors propose an improvement of the definition of planets based on a factor represented by the greek letter mu. What is "mu"?
The ratio between the mass of a body and the mass of all other bodies that share its orbital zone can be abbreviated μ
Starting at the center, the interior of Saturn
probably consists if
a small solid core, a liquid metallic
hysdrogen zone, a liquid molecular hydrogen zone,
and an outer gaseous hydrogen zone
What does it mean by the mean sun?
It is an imaginary object that moves uniformly in a perfect circular orbit. Sometimes ahead of the real sun and sometimes behind.
What type of object will be formed by a stellar core whose mass is 2.06 solar masses?
Neutron star (Black hole for even larger)
Do you think Earth is in any danger of a runaway greenhouse effect like that on Venus?
I think it is highly unlikely cause we would need incredible heat to boil off our oceans and for volcanic activity to slow down
solar constant
7th planet
everything that exists
*Galilean satellite
*no craters
*possibly liquid water below water ice
moving away, longer wavelength
breaking apart complex atoms
the (usually elliptical) path described by one celestial body in its revolution about another
cliffs formed by mercury shrinking
planet with highest surface temp
Ursa Major
constellation: the big bear
attractive force between massive objects
________'s density is relatively low.
The Moon
. Red giants like betelguese
upper right
Weak Nuclear Force
Short range...responsible for radioactivity- Second weakest force after gravity...
globular clusters
large groupings of older stars
movement of earth around it's axis
When Earth wobbles on its axis.
A large conglomeration of galaxy clusters and galaxy groups; typically, more than 100 million light years in size and containing tens of thousands to hundred of thousands of galaxies
age of sun
5 billion years old
Radar showed Mercury rotates ______ times for every _____ revolutions.
Celestial Sphere
an imaginary rotating sphere of "gigantic radius", concentric and coaxial with the Earth.
Faces the earth half maria and highlands
when supernovas promote more star formation this is called:
self-propagating formation
formed at the center of the protoplanetary disk, orbited by dust and grains
brighter areas on the suns surface often associated with sunspots similar to flares but last for weeks
apparent line that seperate earth and sky.
an imaginary line that passes through Earth's center and north and south poles,about which Earth rotates
Where are elliptical galaxies elliptical
in cross section
Spiral Galaxies
Young Stars
"SO" - spiral w/o arms
"Sa" - Large central bulge, tight arms.
"Sb" - Mid sized central bulge, looser arms
"Sc" - Smallest central bulge, loosely spiraled arms
First Greek to profess a Sun-centered universe
Stationary Object
Object could be stationary and observer could be moving to produce Doppler effect
cosmological horizon
The boundary of our observable universe, which is where the lookback time is equal to age of the universe. Beyond this boundary in spacetime, we cannot see anything at all.
the movement of an object around another object
types of telescopes
1. prime focus
2. newtonian
3. cassegrain
4. schmidt-cassegrain
determined by or pertaining to the stars
electron degeneracy pressure
pressure produced by repulsion of closely packed electrons. happens in white dwarfs
planet close to Earth that is covered with clouds
prime focus
the point in a reflecting telescope where the primary mirror focuses light.
True or false stars in a constellation (like the milky way) only look close together from Earth, but may be very far apart.
Gas giants atmosphere contains:
90% hydrongen and 10% helium
Stars rise in the east due to
Daily Motion
the distance that light travels in one year
Summer Solstice
The point on the celestial sphere where the sun is at its northernmost location
the level in which an electron gains enough energy to escape the atom completely; the atom is left with a positively charged ion
Nuclear Fusion
a nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy
Circumpolar Star Trails
Since circumpolar stars never set, they trace circles in the sky as the Earth rotates.
an object that orbits Earth or any other object in space.
Blue shift
An increase in the measured frequency of light from an approaching source; called the blue shift because of the increase is towards the high, or blue, end of the color spectrum
Where is surface temperature of a star measured
Tycho Brahe
made observations used by Kepler of planetary motion
the total or partial hiding of one heavenly body by another
If an object exceeds the escape speed, its motion is said to be _ , and the orbit is no longer an orbit
Lunar eclipse
Occurs when moon passes through earths shadow, can only occur during a full moon (light from moon is blocked)
milky way
the spiral galaxy containing our solar system. With the naked eye it is observed as a faint luminous band stretching across the heavens, composed of approximately a trillion stars, most of which are too distant to be seen individually.
What tool is used to explore our solar system?
doppler effect
An observed change in the frequency of a wave when the source or observer is moving
Continuous spectra
spectrum of a common light bulb spans all visible wavelengths, without interuption
True or False: A comet that has an orbit
around the sun inclined to the ecliptic
plane by 65 degrees probably originated in
Kuiper Belt.
_______ is the main source of thermonuclear fusion of hydrogen to form helium operating in the cores of massive stars on the main sequence
The CNO cycle
A large round pit caused by the impact of a meteroid.
Circumpolar Stars
Stars close enough to the poles that they never set below the horizon.
star population II
located in halo, only red stars, elliptical orbits (redshifted), almost no gas or dust, H & He only
- very old! 10-12 billion years
The Hubble Telescope was placed in Earth orbit by a joint effort between which two space agencies?
spectro graph
a device that can break light into colors and produce in image of a resulting spcetrum
what parts of the spectrum shows the rainbow
visible light
What did Ptolemy's theory explain correctly and what did it fail to explain?
Correctly:-fairly good approximation of planetary orbits (circles)failed to explain:-retrograde motion-planetary brightness
2 parts of big band
inflation and cosmic microwave background
Comet Tail
when a comet coma is hit by solar wind, These particles form a tail called the dust tail. At the same time, the solar wind -- that is, the flow of high-speed electrically charged particles from the sun-converts some of the comet's gases into ions (charged particles). These ions also stream away from the coma, forming an ion tail. Because comet tails are pushed by solar radiation and the solar wind, they always point away from the sun.
apparent daily motion
the motion that objects take from east to west along an arc.
heliocentric model
the sun is the center of the solar system
tropical (ordinary) year
time from one vernal equinox to the next
The moon has phases...
because it revolves around the earth in one month
Winter solstice
December 22, when the sun is at its southernmost point
29.5 days
how many days does it take for a complete moon cycle to take place?
T Tauri star
A young star surrounded by gas and dust. Believed to be contracting toward the main sequence. (p. 184)
Full Moon
the phase of the moon in which it is visible as a fully illuminated disk; occurs when the moon is on the opposite side of the Earth
How did the oceans form?
Water came here from meteorites 4 billion yrs ago.
New moon
The phase of the Moon when the moon is not visible
what are high tides?
ocean bulges where the earth is closer and farther from the moon
Excited State
When an atom or an ion gets an amount of energy greater than it has in its least-energy state
Moon Phase causes
depends on how much of the lit side we see
The Milky Way Galaxy
What is the galaxy our solar system is in?
If the volume of the universe is finite, rather than infinite, then: (a) the age of the universe must be infinite. (b) general relativity must be the correct theory of gravity. (c) space must be curved. (d) the universe does not evolve.
(c) space must be curved.
The Sky is blue because ____
molecules in the air scatter the Sun's blue light in random directions
Phases of the moon ....
you see depends on how much of the sunlit side of the moon faces Earth
Sun's Orbit around the Milky Way
Takes 230 million years for the Sun to go around the Milky Way once
If Pluto isn't a planet, what is it?
It is most likely from the Kuiper belt, hence a "KBO" object like 2003 UB313 or Quaoar
Which of the following is a correct statement of Newtons 2nd law of Motion
For the same amount of applied force, the lower the mass, the greater the acceleration
Which is the net result of the proton-proton chain?
4 protons = 1 helium 4 + 2 neutrinos + gamma rays
vernal equinox
la costellazione
Beta Ursa Major
used a telescope
sunrise conditions
season and latitude
orbited the moon.
apollo 7
Obtained the first observational evidence that spacetime is curved
Gamma ray
electromagnetic radiation emitted during radioactive decay and having an extremely short wavelength
Molecular Clouds
prime areas for formation
Gas giants
Outer planets; known as
What is Haley's Comet?
Short period comet
Speed of light-
3 x 10^8 m/s
instrument that separates light into colors and makes an image of the resulting spectrum
region of the atmosphere which contains ions
Star expands into a red giant
Who wrote the oldest recorded heliocentric theory?
located between mars and jupiter
astroid belt
North and south aurora
aurora borealis&#13;&#10;aurora australis
the process of emitting radiant energy in the form of waves or particles
first observed by Galileo, consist of umbra and penumbra parts, appear dark and irregular
Usually appear in groups or pairs (one has north polarity and one has south polarity)
solar prominence
large eruptions of luminous hydrogen gas that rise thousands of kilometers above the chromosphere
Big Bang
the cosmic explosion that is hypothesized to have marked the origin of the universe
any of system of bright elongated streaks, sometimes asociated with a crater on the moon
Absorbtion lines
the first stellar spectra were classified only by the strength of _________ of hydrogen.
Edwin Hubble
proved that other galaxies existed beyond the edge of the Milky Way
Gaia hypothesis
Theory that all things are interconnected
The gasses surrounding Earth and also the gasses that surround the sun
A measurement of distance from the equator, expressed in degrees North or South
The first American craft to carry astronauts.
Hint, also the name of a planet.
a force that changes rotation (angular momentum)
astronomical time unit based on the Moon's orbit
Trojan Asteroids
Share an orbit w/Jupiter. Same distance and same time to orbit around Sun as Jupiter. Split in 2 groups, named after Trojan war.

Eastern = 60 degrees ahead of Jupiter
Western = 60 degrees behing Jupiter

Held in placeby competing gravity by Jupiter and the Sun.
neutron star
an extremely dense, compact star composed primarily of neutrons, esp. the collapsed core of a supernova.
Optical Telescope
a telescope that uses lenses or mirrors to collect and focus visible light
the point where the moon is farthest from Earth
a mixture of frozen gases and tiny particles of dust
area dense and hot enough for fusion to occur
Hans Lippershay
A Dutch eyeglass maker, invented the telescope in 1608.
the layer of the susn's atmoshere that has a reddish glow
Discovery of Uranus' Rings
-Occurred when astronomers observed the planet eclipsing a background star.
-They observed "blips" in the brightness because the rings were blocking some of the light before the planet crossed sight
larger supplies of ___ mean a greater speed of fusion and hence shorter lifetime for main-sequence stars
when light elements were created
during the big bang
a streak of light caused by a meteoroid burning up in the earth's atmosphere.
What happens to more massive stars
They Contract quicker
Continuous Spectrum
Hot solid, liquid, gas at high pressure
how much faster is earths rotation than the moons each day
50 minutes
the planets stay in orbit around the sun because of
Vera Rubin
Known for her research of dark matter.
The apparent change in positoin of an object due to a change in the location of the observer
in columbus (40°N)
apparent paths are tilted 60° from the horizon
Emission Line
an intensity peak in a spectrum that is due to sharply defined emission of electromagnetic radiation in a narrow range of wavelengths
Intrinsic brightness
The brightness a star would have if not attenuated by distance or intervening gas or dust. As opposed to apparent brightness which it has as measured at a distance
The 3rd planet from the Sun; the only planet known to support life because of its liquid water and atmosphere, the protective atmosphere maintains temperature.
stellar spectroscopy
the study of the properties of stars encoded in their spectra.
Planets, stars, rocks and people emit t____ r_____ that depends only on t_____
thermal radiation, temperature.
the universe is cooling and becoming less d___. so it must have been h___ and d___ in the beginning.
dense, hot, denser
geosynchronous orbit
the orbit of a satellite that revolves around Earth at the same rate that Earth rotates
a small robot that moves around on the surface, mainly to collect and analyze soil and rock samples
Star A has a higher parallactic angle than does Star B. Which is closer to earth?
Star B.
conservation of energy
the principle that energy can neither be created nor destroyed, but can only change from one form to another
The first human to set foot on the moon was
Neil Armstrong
white dwarf
the blue-white hot core of a star that is left behind after its outer layers have expanded and drifted out into space
radio lobes are
globs of gas created and stimulated by jets of radiation from center of galaxy
autumnal equinox
the day of the year that marks the beginning of fall in the northern hemisphere
light year (ly)
the distance that light can travel in one year
Tropic of Capricorn
a line of latitude about 23 degrees South of the equator
spring tide
a combined sun and moon force with the greatest difference between low and high tide
Black hole
a region of space where the pull of gravity is so great that nothing, not even light, can escape
Which mass or mass range refers to the critical size or sizes of a white dwarf?
1.4 solar masses
What type of star is the sun classified?
medium-sized, medium temperature star.
penumbral lunar eclipse
an eclipse of the Moon in which the Moon passes through the Earth's penumbra but not through its umbra
during a solar eclipse one may see
stars/ planets in the day
arrangement of planets in our solar system
mercury, venus, earth, mars, jupiter, saturn, uranus, neptune
what happens when light has a high frequency
its wavelengths will be shorter
What is the First Hallmark of Science?
Modern science seeks explanations for observed phenomena that rely solely on natural causes. A scientific model cannot include supernatural elements.
Why are these inner planets grouped together? What characteristics do they share?
Rocky, Thin (or no) atmospheres, Few (or no) moons, High density, Small size, Close to the Sun, Relatively close together
what happens when 2 galaxies collide
they pass through each other but the gravity of each galaxy distorts the other
Name the four theories of the Origin of the Moon.
1. The Coformation Theory, 2. The Capture Theory, 3. The Fission Theory, 4. The Giant Impact Theory
How are galaxies important to our existence?
We are in the universe connected with things around us. the sun evolved with other stars as part of the system, the big facotry that created us. Production of carbon is important, it is a porduct of generation of other stars.
C. Cepheids are too faint to be seen beyond that distance, even with HST.
Why does the Cepheid "standard candle" have limited usefulness beyond 20 Mpc?
A. Distant galaxies are seen in the past, when Cepheid variables behaved differently than they do today.
B. Distant galaxies are so young they do not contain Cepheids.
C. Cepheids are too faint to be seen beyond that distance, even with HST.
D. The light variability of Cepheids diminishes with distance so they do not appear to vary there.
E. Older distant Cepheids are of population II, where the period-luminosity relation no longer works.
What are the temperature ranges for stars?
Range form 3000K which would be a red star to blue-white stars which are 50,000 K
if you look t the same region of the sky for several nights the position of the stars
do not apper to change in relation to one another
/ 264

Leave a Comment ({[ getComments().length ]})

Comments ({[ getComments().length ]})


{[ comment.comment ]}

View All {[ getComments().length ]} Comments
Ask a homework question - tutors are online