Astronomy v Flashcards

Terms Definitions
Full Moon
mega (M)
10-6
Young Star
Main Sequence
Pulsars
spinning neutron stars
geosynchronous
in time with earth
amplitude
size of the wave
refracting
to subject to refraction.
flare
a sudden burst of flame
Radius
(m) determined by observation, directly proportional to Luminosity (R2 -->L)
Aphelion occurs on ...
July 4th
Lunar Eclipse
Moon in Earth's shadow
Irregular Galaxy
smaller, oddly shaped, younger stars
nova
a star that suddenly becomes brighter
The star-gas-star cycle will continue forever because stars are continually recycling gas (t/f)
False
Processes of Earth
Differentiation, Convection, Plate tectonics, Tidal interaction
Ultraviolet light
Region of the electromagnetic spectrum, just beyond the visible range, corresponding to wavelengths slightly shorter than blue light.
400 billion
number of other galaxies found
proved earth's spherical shape through observation
aristotle
Solar Eclipse order
Earth-> moon -> sun
observatory
Location where many optical telescopes that professional astronomers use are housed
atmosphere
the gaseous envelope surrounding a heavenly body
Magma
liquid rock from the mantle, comes through the crust in volcanoes
cosmic background radiation
radiation uniformly detected from every direction in space
orbit
the ellipse shaped path Earth follows as it revolves around the sun
Comets
small, icy objects of frozen
water and other volatile
material with bits of rock
mixed in
Oort cloud
the region beyond the planetary system, extending to 100,000 AU or more, within which a vast number of comets orbit the Sun
triple stars
a star system with three stars
Temperature
the average kinetic energy of the individual particles
Halo
the oldest part of the milky way
earthshine
the sunlight reflected from the earths surface.
Asteroid
A small rocky body orbiting the sun
constellation
group of stars that form a pattern
Chromosphere
Layer of the sun's atmosphere located above the Photosphere and beneath the corona. It is reddish in appearance and hard to see.
auroras
caused by the deflection of incoming radiation by the Earth's magnetosphere
Spectrograph
breaks light up into its various wavelengths
horizon
the small circle of the celestial sphere whose plane is tangent to the earth at the position of the observer
geological activity on Earth
plate tectonics, volcanoes, presence of a plantary magnetic fiel
Nebula
large cloud of gas and dust particles that clump together to form stars, planets and galaxies
pre-main-sequence star
the stage of star formation just before the main sequence; it involves slow contraction of the young star.
Visible Light
Greatest amount of the Sun's radiation is in this region.
the largest asteroid has a diameter of
1000 kilometers
basic types of telescopes
simple refractor (objective lens), reflecting (newtonian and cassegrain)
solstice
First day of summer. First day of winter. The noon sun is directly overhead at 23.5 degrees.
tidal range
is the difference in height between successive high and low tides
phases
The different shapes of the moon as seen from Earth.
what physical property of a star does the spectral type measure
temperature
eccentricity
A measure of how much an ellipse deviates from a perfect circle; defined as the center-to-focus distance divided by the length of the semimajor axis
Heliocentric
Theory that sun is center of the universe
inner planets
the planets closest to the Sun: Mercury, Venus, Earth, and Mars; rocky and smallest of the planets
Parallax
the apparent change in position of an object when seen from different places
umbra
the very darkest part of the moon's shadow, is cone shaped; sunlight is blocked in this area; only people within the umbra experience a total eclipse
sunrise
The rising of the Sun above the horizon; the time when the uppermost portion of the Sun's disk appears above the horizon
This force binds positively charged nuclei of atoms together?
Strong Nuclear Force
epicycle
a small circle the center of which moves around in the circumference of a larger circle: used in Ptolemaic astronomy to account for observed periodic irregularities in planetary motions.
Red giants
large, cool stars to the upper right on the H-R diagram
rotate
turn on or around an axis or a center
away from
In the universe all objects are in motion and moving ___________ each other.
rings of saturn
made of mostly tiny particles composed of water ice, rocky and carbon compounds
Reflection
The bouncing of light off a surface; A way to gather and focus light
when a star becomes unstable it may eject shells of gas into space forming
planetary nebulas
Big Bang
Galaxies are seen to originate from a single point in time in an event called this
colors of visible light
red, orange, yellow, green, blue, indigo, violet
The Great Dark Spot is a giant oval feature
on
Neptune
sidereal month
27 days, 7 hrs, 42 min, 11.5 seconds
aphelion
the point in its orbit where a planet or other solar system body is farthest from the Sun.
vernal equinox
The first day of spring in the Northern Hemisphere.
time dilation
the slowing of moving clocks or clocks in strong gravitational fields
galaxies
a huge group of stars that are bound together by gravity - There are billions of galaxies in the universe - the largest have more than a trillion stars (1,000,000,000,000)
Perigee
Point in the sky where an object is closest to the Earth
Spiral Galaxy
a galaxy with a bulge in the middle and arms that spiral outward in a pinwheel pattern
What is the zodiacal light?
Sun reflected off interplanetary dust particles
brown dwarf star
a star smaller than 0.1 solar mass that cannot compress its core enough to initiate hydrogen fusion
red giant
A star that expands and cools once it runs out of hydrogen fuel
MILKY WAY GALAXY
The name of the galaxy where we live.
Absolute Magnitude
The measure of how bright a star would be if it were located 10 parsecs from Earth
apparent brightness
The brightness of a star as seen from Earth
The moon is a natural satellite. It revolves around the earth in
27 1/3 days.
no hydrogen and cannot generate energy by fusing hydrogen atoms into helium atoms.
Can shine for billions of years before completely cooling.
What happens to white dwarfs
Which of the following correctly describes
the meaning of albedo?
Reflectivity: (albedo) the fraction of incoming sunlight the planet reflects
Ex: wearing a black shirt
Of which constellation is the Big Dipper a part? What image is associated with this constellation? (In other words, what does it mean or represent?)
Ursa Major - Big Bear
proper motion
The motion of an objet in the plane of the sky, perpendicular to our line of sight.
What are the surface features of the moon?
maria, highlands, craters, rays
Mars Spacecraft: Name and what did they find?
Mariners: fly-bys that saw craters, photographed all of mars.
Viking: mapped the entire planet, looked for life.
what does a solar system consist of
star with planets orbiting around it
The scarps on Mercury were probably caused by
D. the crust cooling and shrinking
The scarps on Mercury were probably caused by
A. tectonic activity
B. meteorite bombardment
C. a tidal bulge
D. the crust cooling and shrinking
E. volcanism
Beyond our own solar system, the planets found to date have tended to be
large jovians with orbits more like terrestrial planets.
Light from Quasars are used to
Probe the density of gas cloudes at different ages of the universe.
The gas clouds produce apsorbtion lines in the spectrum of the quasar.
What is a visual binary star?
Two stars orbiting each other and they can be seen from earth
binary stars: Proceed to white dwarf with accretion disk (nova)
b) The first star ejects its outer envelope, leaving
only a white dwarf, The second star enters its red giant phase, The second star swells up, fills its Roche lobe,
and begins to transfer mass back to the first star,
which is now a white dwarf, The gas falling down toward the white dwarf does not strike its surface directly, because it has too much angular momentum, instead it forms a disk around the white dwarf, the gas spirals inward and angular momentum is carried outward, the gas w/ hydrogen accumulates until there is enough to turn into helium, burning of gas leads to nova outburst and ejects shell of gas from the system, the mass of the white dwarf becomes too large to be supported against gravity by electron degeneracy pressure, it collapses, and a supernova explosion results
What is a perturbation? What kinds of perturbations are there? What does a perturbation affect?
A periodic or linear modification of one (or more) of the 5 parameters of the osculating orbit of a body…

Perturbations occur in two varieties, Secular and Cyclical. Secular perturbations are those variations that are linear in their nature, varying in value in one direction or the other, increasing or decreasing, positive or negative, potentially forever (or until the perturbing force is removed or altered). Cyclical perturbations, on the other hand, cause an oscillation or rhythmic variation in an osculating element, back and forth, increasing and decreasing, synchronized or coordinated with some gravitational encounter with a third (or fourth, or fifth, …) body.

Sparkles thinks that perturbations effect the moons orbit but don’t trust him on that.
A galaxy of Hubble type SBc has
a bar, a small bulge and open spiral arms
What takes up most of the mass in the Solar System?
- Sun
- takes up 999/1,000 of the mass
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