Astronomy Exam 5 Flashcards

Terms Definitions
aphelion
...
Kirchhoff's laws
...
jupiter
jovian planet
Phases of moon:
...
uranus
-1st "non-ancient" planet
-lots of moons
-can detect faint rings from occultations of stars
Saturn
planet with big rings
Kinetic Energy
energy of motion.
filaments
are prominences seen from above
short wavelengths correspond to
high frequencies
reflecting
A_________telescope uses mirrors to focus light
hipparchus
Greek astronomer and mathematician who discovered the precession of the equinoxes and made the first known star chart and is said to have invented trigonometry (second century BC)
proton
a heavy positively charged nuclear particle
weightless
associated with free-fall here because a free-fall renders one weightless
Copernician Revolution
This revolution occured after Copernicus's theory about a sun-centered universe was announced b/c it made major changes in science and society
Energy transport
Conduction, convection or radiative diffusion
Sillicates
Minerals that contain silicon and oxygen
ultraviolet (UV) radiation
electromagnetic radiation of wavelengths shorter than those of visible light but longer than those of X rays.
geocentric universe
earth is at the center
Penumbra
Shadow formed by a partial eclipse
Variable Stars
Stars which have changing brightnesses (Beatle Juice) due to phases of their life that the enter when the begin to die.
mass
the amount of matter in an object
Comet
masses of ice with embedded rock debris,
arc
part of a circle around the earth
conduction
heat transfer by hot atoms bumping into colder atoms
Planet
any of the celestial bodies (other than comets or satellites) that revolve around the sun in the solar system
Parallax
The shift in an objects position caused by the observers motion
Absorption spectra
when electrons jump they absorb certain frequencies of light --> black lines (gaps)
mare
latin for "sea", a large, relatively crater-free plain on the Moon.
Moon's Sydonic Period:
The sydonic period is 29.3
galaxy
a large system of stars, star clusters, gas, dust, and nebulae orbiting a common center or mass.
Intensity
the amount of radiant energy emitted per second per unit area. Units for electromagnetic radiation: watts per square meter (W/m^2)
Acceleration
Change of velocity per unit time (velocity changes in a circular motion, even at a constant speed)
Axis
An imaginary line that goes through the earth.
Rotation
Tends to make a contracting cloud bulge in its midsection and then flatten into a disk
period-luminosity relation
The relation between period of pulsation and intrinsic brightness among Cepheid variable stars. (p. 256)
precession
the act or fact of preceding; precedence.
Mars
2 permanent polar ice caps are found here
Max Planck's analysis of blackbody radiation
light is quantized!
weak nuclear force
a nuclear interaction involved in certain kinds of radioactive decay
Umbra
The darkest part of the moon's shadow. Only people in the umbra see a solar eclipse.
Frequency
The number of waves passing a given distance in a set amount of time measured in Hertz (Hz).
orbital energy
the sum of kinetic and gravitational potential energy
Waxing
The sunlit fraction of the moon is getting larger
red giant
stars that have a surface temperature of over 4000 degrees Kelvin, are over ten times the Sun's mass, and are a hundred or more times as luminous
light-year
the distance light can travel in a year (about 10 trillion km)
scientific evidence BIG BANG
*hubbles expanding universe using doppler effect**left over radiation. . black body radiator. . 1964 bell lab**hydrogen adn helium abundance
Lunar Eclipse
occurs when Earth is directly in between the moon and the sun
Earth
third planet from the sun; has an atmosphere that protects life and surface temperatures that allow water to exist as a solid, liquid, and gas
Circumstellar Disk
The remains of he accretion disk around a young star from which a planetary system may form
The major planet whose spin axis lies almost in its orbital plane is
Uranus
parabola
a geometric curve followed by a body that moves with a speed exactly equal to escape velocity
intensity of solar radiation
the measurement Solar radiation describes the visible and near-visible (ultraviolet and near-infrared) radiation emitted from the sun. based on the mean of the earth-sun
neutron
an atomic particle with no charge and approximately the same mass as a proton
Decrease the mass, radius will increase
The mass-radius relationship discovered by S. Chandraskhar shows that if you _____________ of a white dwarf, it ___________.
retrograde motion
when planets move west relative to the stars for a few weeks or months
Quasar
a distant galaxy with a black hole at its center
doppler effect
An observed change in the frequency of a wave when the source or observer is moving
partial melting
rocks do not have a fixed melting temperature (like pure ice) but melt over a range of temperatures; in the low part of the range liberates some components preferentially, leading to liquids (magmas) different in composition from the initial rock (part of differentiation)
fate of the universe depends on the ________
matter density
horizon
eye level as you stand and turn around in a circle
solar cycle
a 22-year cycle during which the Sun's magnetic field reverses its polarity twice.
Apollo 15: Destination
4th mission to land on the moon
Supernova
When a star has exploded and blown all its glowing matter into space.
elliptical galaxy
A galaxy shaped like a round or flattened ball, generaly containing only old stars.
Solstice
The two days during a year that mark the longest and hortest periods of daylight.
Oort cloud
the very distant "home" of comets and other leftovers from SS formation
Local Group
A gathering of roughly 30 Galaxies in which the Milky way belongs
What are pulsars?
These are believed to be rapidly rotating neutron stars. They give off rapid radio pulses on the order of a second. We think they are rotating neutron stars because no star could pulsate that fast without being broken apart.
whole moon cycle
new moon to new moon: 29.5 days
Galileo Galilei
First person to use a telescope to see some moons of Jupiter
subgiant branch
a region of the H-R diagram defined by stars that have left the main sequence but have not yet reached the red giant branch
What two quantities affect gravity?
mass and distance-more mass higher gravity, further distance less gravity
Absolute magnitude
The magnitude of a star would have if it were precisely 10 parsecs away
What does heat flow measure?
The thermal energy leaving the surface.
Beta Deca
The decay of a neutron into a proton by emission of an electron (beta ray) and an antineutrino. The decay of a proton into a neutron by emission of a positron and neutrino
Summer solstice
June 21, when the sun is at its northernmost point
Great Red spot
A long lived high pressure bulge in Jupiter's southern hemisphere.
Main Sequence
a star that is at the point in its life cycle in which it is actively fusing hydrogen nuclei into helium nuclei, also the band of it Hertzsprung-Russell diagram depicting such stars
could not see earth
What would an astronaut on the far side of the Moon see?
main sequence lifetime
the amount of time a star spends on the main sequence, fusing hydrogen into helium in its core
Azimuth of a star
how many degrees along the horizon it is and corresponds to the compass direction
why is venus much hotter than the earth?
greenhouse effect of venus' atmosphere
the sun is the center of the solar system
The Heliocentric model assumes
Mars: distance / orbital period
1.5 AU from the Sun, Orbital period approximately 2 years
Explain the capture theory of the Moon's formation in a sentence or two. Explain why this theory has problems explaining the mass ratio of the Moon compared to the Earth and the isotope fingerprints of the Earth and the Moon.
The Capture theory states that the Earth and Moon formed independently of each other, and that to Moon was captured by the Earth's gravity at some point. This theory is now hard to believe because the Earth would not be able to capture the Moon without some sort of slowing mechanism because of it's large mass. In addition, the Earth and Moon isotope fingerprints are the exact same, so it is impossible that they formed separately and then randomly met.
Kepler's first law of planetary motion
a planet moves on an elliptical orbit with the Sun at one focus
How can apparent sizes and separations of celestial bodies be measured?
Length of your finger is around 1 degree.
Length of your closed fist is around 10 degrees.
Length of the spam of your hand is 18 degrees.
All have their poles approximately perpendicular to the exliptic
Whcih of these is NOT true of all jovian planets?
Which of the following is not a real difference between asteroids and comets.
Asteroids orbit the Sun while comets just float randomly around in the Oort cloud.
the existence of the disk of our Galaxy: (a) is in considerable doubt. (b) was discovered by Harlow Sagittarius. (c) is a consequence of matter flowing out of a monster black hole. (d) is a consequence of the rotation of the gas cloud that contracted to f
(d) is a consequence of the rotation of the gas cloud that contracted to form our Galaxy.
Mond
moon
Average Density=
Mass/volume
force
mass x acceleration
September 21
Autumnal Equinox
WIMPS
-weakly interacting massive particles
-only interact with gravity
Fnet not 0
unbalanced forces
autumnal equinox
fall, Semptember 21
blue shift
higher frequency-shorter wavelength object moving toward you star or galaxy
insolation
incoming solar radiation,the suns electromagnetic energy that reaches earth at a specific location, intensity of depends on
•angle of insolation(high angle, more direct)
•duration of insolation
•type of surface hit
•cloud cover (moisture in the air)
terrestrial planets
earth-like planets
smaller, more dense, contain proportionally more rocky material, have slower rates or rotation, and meager atmospheres
gravity
the attractive force between objects
radiation
transport by fluctuating electrical and magnetic fields
space
all the area beyond earths atmosphere
Undifferentiated asteroids are c______ c_______.
carbonaceous chondrites
Aristotle
Most associated with ancient greek world view (Geocentric) 1. Do not always feel wind 2. Stars don't get bigger ; reason to believe Earth didnt move
primary atmosphere
hydrogen, helium, methane, ammonia, water vapor
how interiors cool off
convection, conduction, radiation
astrophysics
applies physical laws discovered on earth to phenomena through the cosmos
globular cluster
a large, round, densely-packed grouping of older stars
Schwarzschild radius
distance from black hole's singularity to its even horizon
universe
All of space and everything in it.
rotate
what the earth does around itself (rotation); creates day and night
Neptune
usually the eighth planet from the Sun; is large and gaseous, has rings that vary in thickness, and is bluish-green in color
mercury
closest to the sun, no atmosphere, half hot half cold
P-waves
- travel through solid, liquid and gas
isotopes
different weights due to the differing number of nuetrons contained
Solar
What kind of eclipse?The blocking of sunlight to Earth that occurs when the moon is directly between the sun and Earth.
Hemisphere
The four quadrants of the earth. North, south,east west.Half a sphere or globe.
meteorite
a meteoroid that has hit Earth's surface
Comets
A small irregularly shaped mass made of ice mixed with a large amount of dust, frozen CO2 and organic matter
asterism
________ is a pattern of stars recognized on earths night sky?
constellations
asterism
Galaxies
Huge groups of stars bound by gravity
four phases of matter
solid, liquid, gas, plasma
astronomy
the study of the moon, stars, and other objects in space
Constellation
Any of the 88 contiguous regions that cover the entire celestial sphere, including all the objects in each region; also a configuration of stars often named after an object, a person, or an animal.
unformitarianism
the law of Physics and Chemistry does not change with time
celestial sphere
the apparent surface of the imaginary sphere on which celestial bodies appear to be projected
Seyfert Galaxy
Type of active galaxy whose emission comes from a very small region within the nucleus of an otherwise normal-looking spiral system.
Ecliptic
Apparent path of the sun across the sky throughout the year
Geocentric
Early model of the solar system and universe in which Earth is stationary, located at the center of the universe, and around all celestial objects that revolve
excited state
orbit of an electron with energy greater than the lowest energy orbit (or state) available to that electron.
Apollo asteroid
an asteroid that is sometimes closer to the Sun that the Earth is.
Copernicus
believes that the Sun was the center of the universe
white dwarf
small hot stars that are leftover center of old stars, Very hot, near end of their life\\
big crunch
force of gravity will pull galaxies together
solistice
two points of time were the northern or southern hemisphere are tilted towards the sun marking the beigining of winter and summer
Inverse Square Law
Tells us how distance affects brightness
Revolution-
The motion of one body about another, as Earth about the sun.
produced by the most violent objects in the universe, not completely understood; these rays are completely absorbed by our atmosphere
gamma ray astronomy
mass of star can be determined using
mass and distance
what is one light year in miles?
8.5 twillion km
which 2 moon phases do neap tides occur
first quater&third
protostar
Early form of a star; This stage lies between the collapsing of dust and gas and the beginning of nuclear fusion
how many manned flights were there in mercury? unmanned?
6. 20
Maria (mare)
"Seas" filled by dark lava that have been cooled
Bar Spiral Galaxy
Like a reg. spiral without swollen center; resembles a bar with arms
Eclipse Seasons
any time during the year when the moon's line of nodes is sufficiently close to the sun for eclipses to occur
Messier Objects (pronounced Messy-ay)
Famous deep space objects discovered by Charles Messier in the 1700s. These objects are given a number preceded by an M. For example the Crab Nebulae is M1.
The Metonic cycle is
used to keep lunar calendars approximately synchronized with solar calendars
equinox
the day and night are of equal length - September and March
what is image acquisition?
charge coupled devices (CCDs) are electronic devices- can be read out and reset quickly
surface liquid water
Earth is the only planet on which temperature and pressure conditions allow surface water to be stable as a liquid
the LASCO on the SOHO
an example of a CME-detecting coronagraph
Mars is also known as the "______ planet"
the RED planet
Acceleration to force law
Force = Mass x Acceleration. Heavier things are harder to accelerate. Heavier things have more force.
What is parallax?
Parallax is how objects seem to change position compared to their background when an observer moves.
what is the brightest star
sirius canus major aka big dog
Most of the stars we see in the sky are
very luminous
conservation of angular momentum
it spins faster and faster as it contracts. rate of rotation increases
What is the temperature of the Corona?
Constant is 3 million Kelvin
About 90% of all stars (including the Sun) lie
on the main sequence
What does the density of a satellite tell you about its composition?
Whether it's rocky or icy
What are 3 active galaxies plus descriptions??
1)Radio galaxy= elliptical and emits radio waves
2)Seyfert galaxy= spiral whose nucleus is luminous & fluctuates rapidly
3)Quasars= distant & show superluminal motion
When the sun nears the tip of the RGB (red giant branch), its radius will be approximately
100 solar radii
Betelgeuse is the bright red star representing the left shoulder of the constellation Orion. All of following statements about Betelgeuse are true. Which one can you infer from its red color?
It's surface is cooler than the surface of the sun.
Explain why the solar nebula collapsed into a disk shape as a result of its rotation
The large interstellar cloud of gas and dust was spinning counter clockwise from the beginning, but once the temp began to increase the rotation increased. The flattening caused by the collisions between particles in a spinning cloud, producing a flat rotating disk.
How did we get our Moon?
Formed without Moon. Earth struck by a large Planetesimial or a side swipe that barely grazed Earth. As result, intruder destroyed along with large part of Earth. Flew off into space, formed by process of Accreation.
The maria does not show signs of cratering
What is not true about lunar maria?
Why are high temperatures for these fusion reactions to operate?
Because the nuclei need to get close enough for the strong nuclear force to come into play and make them fuse. If they aren't close enough, then the electric repulsion pushed them away. If they are moving mast enough, then they can get close enough for this to occur. So the higher temp. gives them the fast velocity to get close enough.
someone was watching you fall into a black hole, what would it look like
you'd be going faster and faster and get smaller and smaller until you disappeared
What is the spin-down age of a pulsar?
An estimate of the age based on the time it would have taken the pulsar to slow down to the present period if it was born spinning infinitely fast
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