Astronomy A100 Flashcards

Terms Definitions
magnetic carpet
...
copernicus
heliocentric theory
Polaris
The North Star.
Satellite
Orbits a planet
Latitude measures
north south position
venus temp
very hot 730k
Measure of nearby galaxies
Cepheid Variable
Variable star
unstable, pulse, brighter, dimmer
Apparent magnitude
Observed magnitude from earth
angular momentum
"circular momentum" momentum attributable to rotation or revolution. = m x v x r
Jupiter, Saturn
Which planets are red/orange/yellow?
Galaxy
(astronomy) a collection of star systems
Io has over 300 active volcanoes
True
Brahe
used parallax observations to explore heliocentric model, if earth moves then parallax should be visible (but not to naked eye so he determined earth is stationary). combination geo/helio model: sun orbits earth, all other planets orbit sun.
rotation
a complete spin on an axis
mass
what "m" stands for in E=mc^2
Thermal-Blackbody
Radiation from a normal galaxy
-Output peaks in visible spectrum
-Peaks at the frequency characteristic of the temperature
equinox
(astronomy) either of the two celestial points at which the celestial equator intersects the ecliptic
Moon
the earths natural satellite, orbiting the earth.
synchrotron radiation
Radiation emitted when high-speed electrons move through a magnetic field. (p. 220)
Telescope
a magnifier of images of distant objects
During what season is the Northern Hemisphere pointed towar the sun?
summer.
Celestial poles
Points about which the celestial sphere appears to rotate
planetary orbits
ellipses, not circles. Discovered by Kepler.
Galileo found
craters and mountains on the Moon
star
a massive, gaseous body held together by gravity and generally emitting light, stars generate energy by nuclear reactions in their interiors
Type I supernova
carbon detonation of white dwarf.
Planet
Celestial bodies made up of rocky and/or gaseous material that revolve around the star; Has to clear its orbital path, Do not emit their own light
constellation
a region of the sky containing distinctive patterns of stars
eccentricity
measure of how flat an ellipse is
focus
maximum clarity or distinctness of an image rendered by an optical system
Revolution
the movement of an object around another object
23.5
the Earths axis is tilted ____ degrees
sunspots
regions of darker color b/c cooler than area around it
The Viking I and II missions investigated what planet?
Mars
granulation
one of the small, short-lived features of the sun's surface that in the aggregate give it a mottled appearance when viewed with a telescope.
Quasar
a starlike object that may send out radio waves and other forms of energy
Astronomical Unit
This is defined as the distance between the earth and the sun. That distance is 150 million kilometers, Light Year is 8 minutes from the sun.
conjunction
the alignment of two bodies in the solar system so that they appear in the same part of the sky as seen from earth
Moons of Jupiter
Which term matches best with Galileo?
What are greenhouse gases?
Visible light passes through atmosphere and warms planets surface
prime focus
The point in a reflecting telescope where the primary mirror focuses light.
Most of the atmosphere of Mars in Carbon Dioxide
True
the higher the number of the stars luminosity class, the _ its luminosity ( Ia and Ib are super giants, V is a mains sequence star)
lower
turbulence
the ever-changing motion of air in the atmosphere that bends light in constantly shifting patterns, whereby distorting it
frequency
It describes the rate at which peaks of a wave pass by a point. It is measured in units of 1/s, often called cycles per second or hertz.
Inner planets
Mercury, Venus, Mars, small and dense and have rocky surfaces "terrestrial planets"
faintest magnitude that can be seen with the naked eye
3rd magnitude
Zenith
the point above the observer that is directly opposite the nadir on the imaginary sphere against which celestial bodies appear to be projected
What is the color spectral shift for objects moving towards us?
Blue
europa
which jovian moon has gotten the most attention from exobilogists?
what is earths atomosphere made of
nitrogen and oxygen
Astronomy
The study of the moon, stars, and other objects in space.
occam's razor
the simplest solution is usually the correct one
action reaction law
forces cannot occur in isolation to every action, there is an equal and opposite reaction
Perihelion
nearest point to the sun in the orbit of a planet or comet
The Sun
What did Copernicus have as the center of the heavens?
Emission Lines
When an electron jumps from a higher to a lower energy orbital
Axis
A line that is in the center of something rotates round.
maunder butterfly diagram
shows how the location of sunspots changes during a cycle
Bounded elongation
when planets are always found within a certain distance of each other
does the same side of the moon always face us?
yes
core
The central part of the sun that is the hottest region.
different types of EM radiation
require different types of telescopes
sidereal time
time reckoned by the position of the vernal equinox
White dwarf
The blue-white core of the star that is left behind cools and becomes a
one revolution of the earth around the sun takes
365 1/4
38. What is the central source of a quasar that emits strong radio emission?
Synchrotron
Asteroid Belt
Most of the asteroids are located in between the orbits of Mars and Jupiter.
first quarter
when you can see half of the sunlit side of the moon
the sun's radiative zone
after convection zone, where heat is dispersed into surrounding hot plasma
Size of wavelengths (from longest to shortest)
red -- blue: Radio--Microwave--Infrared--Visible--Ultraviolet--X Ray--Gamma Ray
absolute magnitude
a measure of the amount of light that a star actually emits
speed of light
what does the C stand for in E=MC^2?
What are the three types of energy transport and which one are important in stars
Conduction, (convection, radiation).
solstices (winter and summer)
the points on the celestial sphere where the Sun reaches its northernmost and southernmost positions, respectively
A faint close star and a bright far star can thus have the same...
apparent brightness
age of stars
determined by how long it takes to use up its hydrogen
valles marineris
Grand Canyon of Mars ; 6km deep , 250 km wide, and 5000 km long
There are _____ basic types of spectra: c_____, e_____ l____ and a_____ l____
three, continuous, emission line, absorption line.
True
True or false: a day and a year on the moon are the same length
The ____ of a star is a measure of the total energy radiated by the star in one second
Luminosity
if they strike earth, they can generate power surges on transmission lines that could cause electrical power blackouts to entire cities
CMEs do what to earth's weather/power
Travel time: sound typically travels through air at about 330m/s, or about a third of a kilometer per second. Suppose lightning hits a tree that is six sound-seconds distant from you; that is, you hear the thunder six seconds after the lightning strikes.
About two kilometers away (roughly 3.2 miles).
How is parallax measured?
It is measured in seconds of arc where 1 sec of arc equals 1 parasec
it reveals a magnetic network which coincides with the supergranulation convective cells that sweep magnetic fields to their edges
how is the chromosphere observed in the light of calcium emission lines?
2 facts about White Dwarf Region
1) lowest luminosity b/c of size
2) always low mass stars (below 10 solar masses)
What does differentiation tell us about the Earth's history
it tells us that the earth was once molten and as a result the higher density matter sank and ligher twords surface. a heavy bombardment caused cooling and radioactive heating caused within caused interior to liquify.
why do light rays essentially look parallel?
the sun, planets, and stars are very far away, so the rays reaching us diverge only very slightly, so they look parallel
What does it mean to be tidally locked?
The Moon is tidally locked to Earth- its rotation rate is the same as the time it takes to make one revolution so the same side of the Moon always faces the Earth.
What can you conclude about a Type I supernova?
A. It was originally a low-mass star
What can you conclude about a Type I supernova?
A. It was originally a low-mass star
B. It was originally a high-mass star
C. Its spectrum will show large amounts of hydrogen
D. Its core was mostly iron
E. The star never reached Chandrasekhar limit
Why do we see different phases of the moon?
because the half of the moon that is illuminated by the sun becomes more or less visible form earth as the moon orbits
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