AST Final Flashcards

Terms Definitions
Orange flame
particles of light
the moon
"monday" came from
planet which appears dark blue
newton's 3rd law
action=and opp reaction
the forth planet from the sun
the pt. directly over your head
a cooler darker spot appearing periodically on the sun's photosphere
-Stronger magnetic fields than pulsars (~1000 times stronger)
-Energy from radiation comes from the magnetic field
-Neutron stars are very efficient in converting mass to energy
-Nuclear reactions(~1% efficiency)
-Neutron stars(~20% efficiency)
The correct order of stellar spectral classes, from hottest to coolest is
spiral galaxy
Galaxy composed of a flattened, star-forming disk component which my have spiral arms and a large central galactic bulge. All spiral galaxies have a flattened galactic disk with spiral arms, a galactic bulge, and a galactic halo. The stellar density increases toward the galactic center. Spiral galaxies have a variety of shapes as seen in Figure 15.2 on page 405 and are classified as Sa, Sb, or Sc. Sa galaxies have the largest bulge and Sc galaxies have the smallest. Sa galaxies have tightly wrapped spiral arms and Sc galaxies have loose, poorly defined spiral arms. Note the large bulge of the Sombrero Galaxy, an Sa galaxy shown in Figure 15.3 on page 406. The disks of spiral galaxies are rich in gas and dust. Sc galaxies contain the most interstellar gas and dust and Sa galaxies contain the least. Page 376 is a full-page photograph of the Whirlpool Galaxy (M51), an Sb galaxy.
Objects with the smallest diameters are:
white dwarfs
Of the Jovian satellites, which shows the oldest, most cratered surface?
The distance between crests of waves, such as those of the electromagnetic spectrum.
All Jovian planets have rings around their equators and at least eight moons.
terrestrial planet
Rocky planets similar in overall composition to Earth.
stands for the orbital PERIOD measured in a year
Give the formula for calculating the half-life.
Retrograde motion is
a planet appearing to move east-to-west among the stars, from night to night.
active galaxies
The most energetic galaxies, which can emit hundreds or thousands of times more energy per second than the Milky Way, mostly in the form of long-wavelength nonthermal radiation
Regulated temperature
the nuclear burning is regulated on the main sequence. If too much energy is temporarily lost, the star contracts and heats, increasing nuclear input. If too much energy is temporarily gained, the star expands and cools, and nuclear input declines
one of the Saturn's moons which is like the rest of Saturn's moons, are SMALL, ICY, NO ATMOSPHERE, and are HEAVILY cratered
The amount of energy radiated by a star per second.
Thermal Radiation
All objects emit radiation. The hotter the object the more it emits.
Noting the turnoff mass in a star cluster allows you to determine its
Inner Planets
planets CLOSEST to the sun are composed of HEAVY elements
The wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather.
Big Ban
The initial explosion that resulted in the expansion of the universe.
The study of the overall structure and evolution of the universe.
A photon of red light has the same ______ as a photon of blue light
cosmological principle
Two assumptions that make up the basis of cosmology, namely that the universe is homogeneous and isotropic on sufficiently large scales. This principle is the foundation of modern cosmology and seems consistent with observations, although it has not been shown to be absolutely correct. The cosmological principle implies that the universe has no edge because the existence of an edge would not allow homogeneity. It also implies that the universe has no center because the existence of a center would not allow isotropy (the universe would not look the same in all direction from a noncentral point). The cosmological principle limits the possible geometries of the universe.
Most forms of solar activity are the direct result of:
magnetic fields
In size and density, both Io and Europa resemble
our Moon
bonded elements (O 2, H 2 O, CO 2)
Interstellar gas is composed mainly of
90%hydrogen and 9% helium
evolutionary track
the path that a star follows across the H-R diagram as it evolves through its lifetime
The phase of the moon during a lunar eclipse is:
accelerating universe
A universe in which a repulsive force (see cosmological constant) causes the expansion of the universe to accelerate with time. Its galaxies will recede from one another increasingly faster, and it will become cold and dark more quickly than a coasting universe.
3. Asymptotic Giant Branch (AGB):
Red giant phase againCore 
contractsEnvelope expands. He and H burning shell. 
Energy supplied by gravity.
Virgo Cluster
The Virgo Cluster is about 18 Mpc (60 million light years) from the Milky Way Galaxy. This rich cluster contains 2500 galaxies.
The two names most associated with the discovery of Pluto are
Lowell and Tombaugh
Newton's version of Kepler's Third Law
p2earth = (4pi^2/G x Msun)a^3earth
Star clusters
a cluster of stars that have a common origin and are in the same region
If the distance between two masses is halved, the gravitational force between:
Stays the same.
standard candle
An object for which we have some means of knowing its true luminosity, so that we can use its apparent brightness to determine its distance with the luminosity-distance formula.
H-R diagrams:
Be sure you can draw one?What type of stars?Bright towards top hottest to left
Newton's First Law
An object in motion (or at rest) will tend to stay in motion (or at rest) until it is acted upon by an outside force.
What are some objects in the solar system?
Planets, asteroids, satellites, comets
hot and bright
how are stars in the galaxies RICH in gas and dust
Supernova Explosions
In a galaxy like the Milky Way - 1 supernova per Century
Supernova Lightcurve (Lecture 14-15, Slide 47)
Brightness of Supernova comes from the decay of Nickel-56 mainly (Cobalt later?)
Type IA - No hydrogen, No helium
Type IB - No hydrogen, Some helium
Type IC - No hydrogen, No helium
Type II - Hydrogen in spectrum
Local Galaxy Group Clusters?
1. 38 galaxies.2. Only 3 large spiral galaxies.
The only probe in the atmosphere of any Jovian planet was launched by
Galileo into Jupiter's equatorial zone
What information does 21 cm radiation provide about the gas clouds
their motion their distribution their density their temperature
The Moon at the horizon appears:
Dimmer than usual due to the atmospheric extinction.
an object for which we are likely to know the true luminosity
What is a standard candle?
One of the effects of Mercury's very slow spin is
extreme variations in its surface temperatures
What is the typical age for a globular cluster associated with our Milky Way?
10 to 12 billion years
What was the Tunguska event?
In 1908, an asteroid broke up in our atmosphere over Tunguska, part of north-central Siberia.
The contents of a solar system, a galaxy and a universe.
Solar system: Star (Sun), Orbiting Planets -8, moons, asteroids & cometsGalaxy:
Ch.19 Q#1: Identify the disk, bulge, halo, and spiral arms and indicates the galaxy's approximate dimensions
The bulge is in the center, disk surrounds it, halo is outside, the spiral arms are in the disk. The milky way is 100,000 light years in diameter, 1,000 light years thick. Sun is 28,000 lights years away from center. *Stars within 10,000 from center are in the bulge*-only counts for spiral arms since they are the only ones that have a disk.
More than ________ percent of the mass in the universe is dark
from a close encounter or collision between two galaxies
Stages of the Big Bang: 1-5
1. Gravity separates from other 3 forces.2. Inflation. The Universe expands at an exponential rate.3. All forces separate from each other. Univ is 
energy, quarks, electrons, positrons, neutrons- some protons4. Neutrons and Protons can no longer be formed & made from photons5. Electrons & positrons no longer made from photons. Beginning of Deuterium bottleneck.6. Deuterium bottleneck END. Nucleosynthesis Beginning7. Nucleosynthesis ENDS. Universe is 75% H, 24% He and 1% He and Li.
How does Mercury's rotation relate to the Sun?
It's rotation rate is 2/3 as long as its year, due to tidal resonances
What age of the earth did CC Patterson calculate? How?
4.54 billion years; he measured the radioactive decay of the Canyon Diablo meteorite
How did Neptune get all the way out there by the Kuiper belt?
Jupiter and Saturn ganged up on it with their 2:1 resonance
700 nanometers
"wednesday" came from
freezing pt in F
types of atoms (hydrogen, carbon)
What is geocentric?What is Heliocentric
Stars in constellations
usually NOT physically associated
When something is taken in, represented by a hand near a source of light and being warmed. The energy is taken into the hand, thus warming it.
The alt-azimuth mounting aligns one axis of a telescope with the celestial pole.
Active geysers on Saturn's moon, Enceladus, is an example of volcanism at low temperatures called ____.
X-Ray radiation
allows doctor to see your insides
Local Supercluster
Collection of galaxies and clusters centered on the Virgo cluster. Also known as the Virgo Supercluster, it is about 50 Mpc across and contains tens of thousands of galaxies.
an ancient superstition not based on the scientific method - is not tested by observation or experiment
The largest asteroid, and probably the only one to be spherical is _________
Mass Limit of White Dwarf
1.4 solar masses
Black Body
ideal absorber and emitter of electromagnetic radiation.
a pulsating source associated with a rapidly rotating neutron star with an off-axis magnetic field
The longest distance across the orbit
Major Axis
Impact craters on the surface of the Earth are most often caused by
Vesto Slipher
In 1912, Vesto Slipher discovered that the spectral lines of all spiral galaxies were redshifted - shifted to longer wavelengths. The redshift is caused by recession - galaxies are moving away from us at large velocities.
Retrograde motion
The apparent motion of the planets when they appear to move backwards (westward) with respect to the stars from the direction that they move ordinarily.
Iron Meteorites
a category of meteorites which is solid chunks of IRON and NICKEL, very DENSE and HEAVY
first quarter
phase btw waxing crescent and waxing gibbous
The chief gas in the martian atmosphere is
carbon dioxide
Pluto is more similar to the jovian planet's icy moons than to any of the other planets
spectroscopic binary
a binary star system whose binary nature is revealed because we detect the spectral lines of one or both stars alternately becoming blueshifted and redshifted as the stars orbit each other
Central temperature of the sun
1.5 x 10_7 K
Type IA Supernova
-No object is left behind
-Brightest supernova, since they produce the most Nickel-56
-Occur in low star-forming environments (In spiral galaxies they avoid spiral arms)
-Also, occur in ellipticals.
-Happens when a white dwarf crosses the Chandrasekhar Mass, 1.4 Mo
The Jovian satellite that has an icy crust surrounding an ocean of water is ___.
During which phase would we not see the moon during the night OR the day?
New moon
Big Crunch
Point of final collapse of a bound universe. The universe has two possible fates: (1) it will continue to expand forever or (2) the expansion will decrease, eventually cease, and the universe will contract (recollapse). The fate of the universe is determined by its density. In a high-density universe, there is sufficient mass so that gravity can stop the expansion and cause a recollapse. This type of universe will eventually form an infinitely dense, extremely hot singularity. This process is known as the "Big Crunch". In a low-density universe, the universe will expand forever and the galaxies will continue to recede from each other. Eventually, the galaxies will be too far apart to be seen from each other and their fuel supplies will eventually be exhausted. The density of a universe in which gravity acting alone is just sufficient to halt the present expansion is called the critical density. If the value of Hubble's constant is taken to be 70 km/s/Mpc, the critical density is about 9 x 10-27 kg/m3. This corresponds to a mass of about 10% the mass of the Milky Way per cubic megaparsec. It now seems that density is not the only factor to be considered, although it is one of the most important.
The surface temperature of the sun is approximately:
6,000 K
The Moon's near side always faces Earth due to
Earth's tidal force
Neap Tides
tides occurring near the times of the first and last quarters of the Moon, when the range of the tide is least; tides are generally weaker during this time.
Early form of a star; This stage lies between the collapsing of dust and gas and the beginning of nuclear fusion
protoplanetary disk
A disk of material surrounding a young star (or protostar) that may eventually form planets.
A distant galaxy with a black hole at its center.
super massive black hole
Giant black holes, with masses millions to billions of times that of our Sun, thought to reside in the centers of many galaxies and to power active galactic nuclei.
Roughly how far is the sun from the center of the Milky Way Galaxy?
10 kpc
Thermal pressure
For most of the lifetime of the star this is the dominant source of outward pressure. With this pressure a star can regulate its temperature.
The most distant objects in our solar system are in
the Oort Cloud
Within 1 Mpc of the sun there are about
45 galaxies
X-ray binary (star) system
a binary star system that emits substantial amounts of X rays, thought to be from an accretion disk around a neutron star or black hole.
What are lunar rilles?
Canyons, caused by lava flows or crustal cracking.
List the Terrestrial planets in order of increasing radius (smallest to largest):
Mercury, Mars, Venus, Earth
The F-ring of Saturn is held in place by
the shepherd moons
Properties of Waves
Water does not move with wave - it just moves in a small circle. Wave carries energy outward.
Describe the components of an ellipse:
Major Axis, Semi-Major Axis, Minor Axis, Focus (plural -- Foci)
How long will the sun last
5 x 10_9 years (5 billion)
disk (of a galaxy)
The portion of a spiral galaxy that looks like a disk and contains an interstellar medium with cool gas and dust; stars of many ages are found in the disk.
Of the following 5 lists, which list is just of Jovian planets?
Jupiter, Uranus, Saturn, and Neptune
As the solar nebula contracts, it
spins faster due to conservation of angular momentum
The fact that part of the earth's core is liquid comes from:
Analysis of earthquakes waves.
What are/aren't the stars mostly formed of? Give percentages
By mass, 99% gas and 1% dust
Two K stars appear equally bright on a photograph, but spectra show that one is main sequence and the other is a giant.
the giant is more distant
So far, beyond the solar system the extrasolar planets have been mostly
large Jovians with terrestrial type orbits
The speed of light is 3.00 × 10 m/s. If 2.00 kg of mass is converted to energy, how much energy will be produced?
1.80 × 10^17 J
3. What process is responsible for much of the observed light from the supernovae?
(d) Radioactive decay of Nickel to Cobalt that is followed by the decay of Cobalt
to Iron
The moons of Neptune are most unusual for which of the following reasons?
one has retrograde orbit and the others have prograde
In the Solar Max video, which contribution did Copernicus make to astronomy?
He developed a model of the universe with the Sun at the center.
The names of the seven days of the week are based on:
The seven naked-eye objects that appear to move among the constellations.
Why is there a "far side of the Moon", that is, why is there a side that we cannot see from Earth?
The Moon rotates once a month.
Which star spends the longest time in the protostellar phase of life?
Lower mass stars take longer in all phases of life.
A parsec is defined as the distance to:
a star whose parallax is one second of arc
Why does fusion occur in the core of the Sun but not in the core of Jupiter?
the mass of Jupiter is too small for fusion to occur
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