Astronomy 3 Flashcards

Terms Definitions
Milankovitch hypothesis
Pluto's moon
configuration of stars
Lunar month
29.5 days
Declination is comparable to
Earth's layers
core, mantle, crust
one celestial body obscures another
equal to earth
size of Venus
Kelvin. An absolute temperature scale.
the brightest star in Orion
ice covered moon, cracked surface
Which moon is the most dense?
Chandrasekhar limit is about _____ times the mass of our sun.
Space telescopes:
Atmosphere issues (Twinkling)-IR, UV, X-rays, Gamma rays cannot penetrate the atmosphere
movement of one object around another
inertia and gravity
keeps planets in orbit
Ecliptic Coordinates
Celestial longitude (measured from position of Sun at vernal equinox) and celestial latitude (measured from ecliptic).
Stefan-Boltzmann Constant
the proportionality constant that relates the flux emitted by an object to the fourth power of its absolute temperature., σ=5.67 x 10 ⁻⁸Wm⁻²K⁻⁴
length of solar cycle
every 11 years
Heavy molecules (Oxygen) move _____ thean light molecules (hydrogen, helium)
is a large bright feature extending outward from the Sun's surface
HR Diagram
the graph showing the absolute magnitude plotted against the surface temp for a group of stars
our milky way has spiral arms (T/F)
the colliding and growing masses of dust and grains
visible surface of the sun, thin spherical shell about 120 miles thick. source of most of the sunlight we see. temperature is 6,000 Kelvin
heliocentric cosmology
Sun centered cosmology. eg. everything in the milky way revolves around the sun
An object's resistance in speed or direction until an outside force acts on it.
Hertzsprung-Russell diagram
chart of the relationship between luminosity and the surface temp of stars
What is a pulsar?
rapidly rotating neutron stars
Spectral types of stars
hotter<= surface temp =>Colder
higher<= Mass =>lower
shorter<= Life =>longer
Tidal Range
The difference between successice high and low tides.
Doppler Shift
Any motion induced change in wavelength of a wave
Cepheid variable
A particularly luminous type of pulsating variable star that follows a period-luminosity relation and hence is very useful for measuring cosmic distances.
Light year
Distance light travels in a year
a measurment of distance from the equator expressed in degrees north or south
comets: basics
-small objects in elongated orbits around the sun
-move slowly in sky: don't streak like meteors
-frozen gases mixed with dust and other junk
-heat up and evaporate when they approach the sun, producing the coma and tail
a number of heavenly bodies associated and acting together according to certain natural laws
thought that the earth was the center of the universe
the spinning rotation of a planet on it's axis.
a change in the direction or magnitude of a velocity
What type of color blindness is the most common?
What do gas giants have?
ring systems and satellites.
This greek used shadows on the summer solstice and measured the size of the Earth.
celestial sphere
A canopy of stars resembling an astronomical painting
type of phase change of matter in which electrons are stripped, causing the atom to turn into plasma
The measure of where along the horizon something is relative to your specific location.
sidereal time
lines of right ascension. runs from north to south
Neap tides
twice a month halfway between the spring tides are weaker than normal tides
mars season
just likes earths, but longer because of longer year
A piece of rock similar to the material that formed into planets; usually found the the asteroid belt.
Radio Telescopes are useful because
all of the above
imperial mathematician
Tycho Brahe held what position in Prague, under the holy Roman Empire?
1st to propose orbits of planets are ellipses
a celestial body moving about the sun, usually in a highly eccentric orbit, consisting of a central mass surrounded by an envelope of dust and gas that may form a tail that streams away from the sun.
What are the disadvantages of reflecting telescopes?
You have blocked images.
black hole
an object whose gravity is so strong that nothing, not even light, can escape
a cooler gas cloud between us and a light bulb can absorb light of specific wavelengths that depend on cooler gas composition and temperature, leaving dark absorption lines in the spectrum
What is a meteorite?
rock from space that falls
remnants from solar nebula
two types: primitive and processed
the point in the orbit of a planet where it is closest to the sun
Continuous spectrum
The whole spectrum (all the colors in the rainbow). They combine to make white light.
lunar eclipse
The blocking of sunlight to the moon that occurs when Earth is directly between the sun and the moon.
elliptical galaxy
A galaxy shaped like a flattened ball, containing only old stars.
Diurnal Motion
The daily progress of the Sun and other stars across the skies because of Earth's rotation.
center of gas distribution
8 kpc away from the Sun
The nearest Star to earth is also known as?
The Sun
what are the three types of galaxy's
elliptical,irregular, and spiral.
Early models of planetary movement had earth where? these models were termed?
at the center; egocentric
schwarzchild radius
something is so small it becomes a black hole
Kuiper Belt Object
Any object located in the kuiper belt. The planet Pluto is thought to be the largest one of these.
Doppler Red Shift
apparent shift in spectrum to the red end due to the movement of the light emitting object in space away from the observer
scientific theory
a model of same aspect of nature that has been rigorously tested and has passed all tests to date
nebular contraction
cloud of gas and dust contracts due to gravity
Spiral Elliptical Irregular
What are the three main types of galaxies?
Summer solstice
June 21, when the sun is at its northernmost point
first quarter
when you can see half of the sunlit side of the moon
evolutionary track
The path a star follows in the H-R diagram as it gradually changes its surface temperature and luminosity. (p. 180)
Third Quarter Moon
the phase of the moon in which the left half of the moon is lit and the right half is dark
the Doppler effect depends on
the external property of the star's motion through space relative to us
2 times of the year when the Sun is at its greatest distance from the equator and day and night are at their greatest difference
what are low tides?
when water gets pulled away from the middle
Ground State
When an atom is in the state of lowest possible energy
Moon Phase causes
depends on how much of the lit side we see
grazing incidence optics to focus the short wavelengths
The Chandra X-ray telescope must use:
Tiny fluctuations in the brightness of the cosmic microwave background from place to place on the sky tell us that: (a) the early universe was perfectly smooth. (b) the expansion of the universe is currently decelerating. (c) our observations are wrong. (
(d) space is indistinguishable from flat.
small changes in the amount of visible light emitted by sun. huge variations in x-ray and ultraviolet output
during 11 year cycle...visible light versus variations in sun's x-ray and ultraviolet output
From the reading "Cargo Cult Science," explain "why the planes don't land" to a typical islander who might ask, in a few sentences.
Although the islanders have used their skills in order to replicate an "airport" to the best of their knowledge, they are lacking the necessary technology to summon the planes to their bamboo-version of an aircraft-landing center. They would have needed more information to successfully attract a passing plane with cargo supplies. During the war, planes may have used this particular island for re-fueling stations, but now the planes find no need to fly over this island. The islanders set up their version of what was there before, but the islanders are lacking electricity, technology, communication devices, a proper runway, ect. (all of which are found in a modern airbase). The locals of the island anticipate the materials of a plane that will never come, unless they improve their island airport. If the islanders would try to communicate with SOS signs, such as large beach fires, they might attract a plane with this method as well.
in a gas, the thermal energy is T.E.=
N (# of atoms/molecules) k (Boltzman's constant) T (temperature
The tiny gaps in Saturn's ring system are
caused by
small moons (gap moons) whose gravity
"clears out" ring particles in the gap
When our Sun finally runs out of nuclear fuel, it will implode, resulting in
a planetary nebula with a white dwarf at the center
Which of the following was a crucial contribution of Galileo in rejecting the geocentric system?
The fact that Venus shows a CRESCENT phase
Where do most stars appear to rise and set?
they rise in the east and set in the west
infrared radiation
il satellite
Alpha Canis Minor
White, yellow
Medium stars
Seven Sisters of subaru
100,000 light years across
United States astronomer who discovered the planet Pluto (1906-1997)
Who invented the telescope?
Hans Lippershey
Individual packet of electromagnetic enery that make up electromagnetic radiation
M stars
less than 3,500 K
the layer above the troposphere
This planet has the hottest surface.
an oval-like shape of most orbits
Which living organisms most resemble the
common ancestor of all life according to
genetic testing?
dust that is found in space
lunar rilles
narro, canyon-like valleys starrting in highlands and working their way down to maria plains
Gravity pulls gas and dust together
transmits a limited wavelength range of electromagnetic radiation
the earth spining on its axis
lifetime = total fuel available/rate at which fuel is used&#13;&#10; &#13;&#10;mass of star/luminosity
Solar System
the Sun, its planets and moons
Flamsteed System
Stars are numbered consecutively from west ot east across the constellation
the largest moon in the solar system
The higher the frequency...
the higher the Energy
disks of spirals rapidly compared to ellipticals
the outer layer of the sun's atmosphere
Drake Equation
expression that gives a probability that life exists elsewhere in the galaxy
A deivice built to study distant objects by making them appear closer
Empirical Science
scientific investigation that is based primarily on observations and experimental data. it is descriptive rather than based on theoretical inference
when sun reaches its greatest distance north or south of the equator
renaissance (1400-1650)
more careful observations of nearby objects leads to more sophisticated models. Culminates with the telescope
a region of complete shadow resulting from total obstruction of light
planets are the leftovers of ___
star formation
a starlike object that may send out radio waves and other forms of energy
terrestrial planet
Any of the earth like planets, Mercury, Venus, Earth and Mars.
the bending of light rays when they pass from transparent medium to another
neutron star
the small, dense remains of a high-mass star after a supernova
collapses in on itself to become a black hole or or become a neutron star (puny)
• Neutron star: a star that has collapsed under its own gravity; it is composed of neutrons
How did the Babylonions explain the universe?
Through myths
Composition of Uranus
Core: Heavy element
2nd layer: Ices and rock
3rd layer: Gaseous hydrogen and helium
-Also has a tilted orbit (as if it were on its side)
tidal force
"stretching force" that is created by the difference in attraction between the side of the Earth facing the moon and the side not facing the moon
light pollution that goes up and gets scattered back into your eyes
starburst galaxies are galaxies that f____ s____ at a very high r____.
form stars, rate.
Solar Flares
the most violent of all solar disturbances. a sudden outward eruption of electrically charged particles such as electrons and protons.
Absorption spectra
allows us to see certain absorption lines
Is acceleration is what: a vector, or a scalar?
tilt of axis doesn't change as earth revolves around the sun
the sun is what kind of star
yellow star
Frank Drake
Found SETI and created the probability equation for intelligent life found in the universe.
what are electromagnectic waves?
oscillating electric and magnetic fields. changing electric field creates magnetic field, and vice versa.
the planet nearest the sun, having a diameter of 3031 mi. (4878 km), a mean distance from the sun of 36 million mi. (57.9 million km), and a period of revolution of 87.96 days, and having no satellites: the smallest planet in the solar system.
tropic of cancer
no shadows on the summer solstice means the Syene is on the
hotter and whiter.
The Sun's spectrum peaks in the yellow-green region (i.e., this region is the most intense part of its spectrum). The spectrum of Rigel (the star in the knee of Rigel) peaks in the short-wavelength end of the visible spectrum. Compared with the Sun, Rigel is
Olber's paradox
is the argument that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe
the line where earth & sky apper to meet
The Milky Way
The galaxy that includes our solar system.
Moon rate of rotations
12 degrees to the east (counterclockwise)
First telescopes were ______. However they could only be so big because ______ made them _______
glass lescenses, gravity, sag
A technique to measure distances - p_____. We observe how their p___ appears to c____ as the earth orbits the sun.
parallax, position, change.
the star at the centre of the Solar System
absolute magnitude
the brightness of stars as if they were all located33 ly from earth for example Polaris's absolute magnitude is -3.63
absolute brightness
the brightness the star would have if it were at a standard distance from Earth
is a large cloud of gas and dust spread out over a large volume of space.
What is differentiation?
The denser material that had fallen on earth sunk directly to the core. differentiation occured by density.
gregorian calender
centuries not divisble by 400 cant be leap years
What is the season in the Southern Hemisphere in December?
It is summer.
metallic hydrogen
a form of hydrogen in which the atoms have been forced into a lattice structure typical of metals
Vernal Equinox
the sun is on the celestial equator & moving north with respect to the equator, march 21st or start of spring
a set of numbers that can be used to locate something
29.5 days
how many days does it take for a complete moon cycle to take place?
turnoff point
The point in an H-R diagram at which a cluster's stars turn off of the main sequence and move toward the red-giant region, revealing the approximate age of the cluster. (p. 208)
arabic, greek and latin
most star names are ______, but there is a mix of ________ for a few famous stars
angular diameter or angular size
angle across diameter of object (moon= 1/2 degrees)
sun spot
areas of gas on the sun that is cooler than the gasses around them
pioneer and voyager
one was early 1970's by US and was first probe to outer planets. the other was in late 70's by US went to 4 outer planets had recorded greeting from earth
Name the other planets in order
Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto
angular size / angular subtend
the angle size that a celestial object takes up in view
What does the weathering of rocks do?
Breaks down rocks into small particles.
Sirius, Procyon, and Betelgeuse: (a) are all at practically the same distance from us. (b) form the asterism called the &quot;winter triangle.&quot; (c) all have practically the same color. (d) are members of the Pleiades cluster.
(b) form the asterism called the &quot;winter triangle.&quot;
1 theory of how the moon formed.
The Capture Theory. The Moon was formed somewhere else in the solar system, and was later captured by the gravitational field of the Earth.
Why is it summer in the northern hemisphere when it is winter in the southern hemisphere?
The northern hemisphere is tilted toward the sun and receives more direct sunlight
Does the moon have a magnetic field?
No, meaning it cannot have a sizeable iron/nickel core.
What two gas giant planets have shown storms called Great Red or Dark sports?
Jupiter (Great Red) - Neptune (Dark Spots)
C. red light from the emission nebulae
Which of these is not a consequence of dust in the interstellar medium?
A. reddening of stars' light that passes through the dust
B. blue reflection nebulae around the Pleiades
C. red light from the emission nebulae
D. the dark nebulae that block 90% of the Milky Way from us visually
E. terrestrial planets like our own
If a barbell weighs 10 pounds on the Moon, what would it weight on Earth?
60 pounds. Surface gravity on the Earth is 6 times that on the Moon.
T or F: The Sun is the largest star in our Galaxy.
False!! Our Sun is just an average star, not too big, not too small.
Swamp, marsh
new moon
!! rises at sunrise, sets at sunset
Milky Way
our galaxy
what does density measure?
Nuclear fusion creates
a glow
Solar Corona
The Sun's outer atmosphere
the universe is very _______
sunspot group
a cluster of sunspots
laws of inertia and gravity
The moon, Hubble telescope and Halley's Comet all are?
An element found in Earth's core
The gravitational disturbance of the orbit of one celestial body by another.
Physical state of matter' solid, liquid, or gas;
Apparent change in shape of the lighted portion of a celestial object
Andromeda galaxy; 3 million light years away
The instrument that analyzes the colors and temperatures of stars best is a:
what is the fall equinox
september 23
photons (EM radiation)
wave-like &amp; carry energy.

diffract (spread out) when they pass by the edge of an opaque body.

wavelength of photon inversely proportional to its energy(shorter wavelength, greater energy).

When separated into their component wavelengths/energies, EM spectrum formed.
Radio Galaxy
Very bright, often giant, elliptical galaxy that emits as much or more energy in the form of radio wavelengths as it does wavelengths of visible light.
meteor shower
Sometimes several meteors appear at once and occur when Earth passes through region of space containing cloud of dust particles associated with comet, visibility depends on the brightness of the moon but can be seen with the naked eye
spherical aberration
an optical property whereby different portions of a spherical lens or spherical concave mirror have slightly different focal lengths thereby producing a fuzzy image
____ Cannot be seen without a telescope.
The angular distance of an object above the horizon.
The Distance measured in the direction of a wave between two successive points of said wave
From the Geocentric Model. A small circle that revolves around a deferent.
the imaginary line that passes through Earth's center and the North and South poles
cosmic microwave background
almost perfectly isotropic radio signal that is the electromagnetic remnant of the Big Bang. COBE satellite. found T appx. = 3K above abs. zero, matches prediction of blackbody spectrum. proves early universe was radiation dominated
Made of ice and possibly frozen gas
A meteroid that survives the trip through the atmosphere and impacts the Earth's surface, forming craters
compound telescope
Contains mirrors (reflect) and lenses (refracting)
all of space and everything in it
false-color image
A representation of graphical data with added or enhanced color added to reveal detail
Solar Wind
the outward flux of solar particles and magnetic fields from the Sun. The solar wind is produced primarily in the cooler regions of the corona, known as coronal holes, and flows along the open magnetic field lines. Typically, solar wind velocities are 300-500 km per second.
born in cyrene (now Shahhat, Libya) in 276 BCE, lived until about 195 BCE 2nd Librarian of Alexandria. At noon on the Summer Solstice in Syene, Egypt (modern Aswan), the Sun was straight overhead and cast no shadows, on the same day the noon sun cast shadows in Alexandria, located north of syene, computed circumference of Earth (Alexandria 5000 stades from Syene), estimate only 15% too large
fission theory
rapidly rotating earth cause moon to pull out
space station
a large artificial satellite on which people can live and work for long periods fo time
Fairly old stars, a range in ages. Relatively rich in heavy elements ("star ashes")
meeting or passing of two or more celestial bodies in the same degree of the zodiac
large, dark flat areas due to lava flow. originally thought to be oceans
A total solar eclipse is visible from only within the moon's ______.
temperature on mars
About 50K cooler than on Earth
Neap tide
Minimum variaqtion in tides, occurs at first-quarter and last-quarter phases of the moon when Sun and moon's gravitational forces cancel
a lens that causes light rays to converge, producing a brighter, larger image of the object being viewed
that which can change the momentum of an object.
Distance from Andromeda Galaxy
2 million light-years (2,000,000 ly)
spring tide
the tide with the greatest difference between consecutive low and high tides
proton-proton chain
fusion of H creates outward pressure; He is produced
nebular theory
gas and dust forming our solar system
Electric fields
Regions of influence that affect other charges particles
The solid portion of a comet, and the only portion that exists when the comet is far from the sun. Dirty snowball a chunk of ice mixed with rocky dust ans some more complex chemicals.
Milky Way Galaxy
the galaxy our solar system is in.
A rocket much travel at least 25 miles per second to escape Earth's gravitational pull
What kind of star is the sun
Main sequence star
Surface of Saturn
(upper cloud level) again similar to Jupiters but more subdued, no hurricane like the Great Red Spot
What is the Bound?
The Universe's density > critical density and it will eventually collapse.
1 ___ = speed of light x 1 year
metonic cycle
The phasing of the tropical year with the synodic month over a 19 year period is called this.
the best images of the planet from earth is seen when mercury is in what phase
half phase
Radiation Zone
Energy created at core of Sun heads towards surface of sun first passing through here by means of the mechanism of radiation.
Water Hole
quite band 21 cm where searching is easier to hear.
Astronomical Unit (AU)
a measurement for distances based on the distance from earth to the sun
Islamic researchers and astronomers
developed many constellation & star names
Which of the following properties of a star cannot be revealed by spectroscopy alone?
D. diameter
Which of the following properties of a star cannot be revealed by spectroscopy alone?
A. surface temperature
B. chemical composition
C. line of sight motion
D. diameter
E. none of the above
synchronous rotation
rotation of a satellite in which the period of rotation is equal to the period of orbit around its primary, leaving the same face always pointing toward the primary:
what mission found frozen water on the moon
lunar crater observation
If it takes 40 minutes for light from the Sun to reach Jupiter and 80 minutes for light from the Sun to reach Saturn, how long will it take light to travel from Jupiter to Saturn?
90 minutes
apparent brightness
how bright a star looks in the sky; the amount of power reaching us per unit area
Local Mean Time
The actual time in a given location based upon the Sun's position at the Midheaven (noon) of the place. Abbreviated LMT; also called True Local Time (TLT).
Black Holes
a mass that has collapsed to so great a density that its enormous local gravitational field prevents light from escaping
What causes eclipses?
When the Earth or Moon passes through the others shadow.
What happened during accretion phase of the early solar system?
Particles grew by colliding and sticking together.
moon's magnetic field
does not exist, it does not have a liquid core
Perhaps confusingly,a circumpolar star is not just any star that happens to be near the North Celestial Pole, but instead any star that never sinks below the horizon during a 24-hour interval.
Suppose you live within 5 degrees of the South Pole on the Ear
Stars near the South Celestial Pole would be circumpolar; in January the Sun would also be a circumpolar star from this location.
partial solar eclipse
not at node, need a special filter to look at it
The radius of a star in solar units is approximately proportional to the square root of the star's luminosity in solar units divided by its temperature squared in solar units. If a star has a luminosity of 100 solar luminosities, and is the same temperatu
10 solar radii
What are the two types of spins for the atoms?
Parallel spins
Antiparallel spins
How often does the sun revolve around the Milky Way?
about every 225 million years.
A pulsar requires that a neutron star
rotate rapidly, have a strong magnetic field, and rotate on an axis that is different from the axis of the magnetic field.
In the Copernican model, retrograde motion:
Is an illusion that occurs when one planet passes another.
how the moon and sun affect the Earth
rise and fall of ocean's tides
That Mercury has a large iron core is evidenced by..
the large mean density of Mercury.
what type of weather is on the moon
no weather because there is no atmosphere
Explain why lower mass gas particles in a gas tend to move more quickly than high mass gas particles.
In order for gas particles to have the same kinetic energy, smaller mass particles must compensate for their small mass with a higher velocity.
K=1/2(mass x velocity)^2
Explain how the crater density of both the maria and highlands, combined with solidification ages of moon rocks from these regions, leads astronomers to believe that the cratering rate on the moon has not been constant over time and that there was an era
If the cratering rate on the Moon were constant, then scientists would expect the crater density of the Maria to be 10% less than on the Highlands, since the radioactive dating age of the Maria is 10% younger. In fact, what scientists found was that the Highlands have between 200-500% more craters than the Maria. This indicates that there was a period during the Moon's early stages where it was bombarded much more than any other time, giving rise the theory of Early Bombardment.
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