Astronomy 102 Flashcards

Terms Definitions
Winter Solstice
radio detection ranging
great red spot
movement around the earth
Astroid Belt Dwarf Planet
velocity of light
frequency x wavelength
measure distances nearby stars, apparent change in position if an object when you look from different place
which planet has 8 moons
a zodiacal constellation between Gemini and Aries, containing the bright star Aldebaran also called the Bull
Galileo Galilei
discovered moon was not smooth
imaginary vertical line that cuts throught the center of Earth and around which Earth spins
a meteoroid that lands on Earth
largest structure known in the universe
falling masses fall at constant speeds
-motion is only possible when things are acted upon
the kind of orbits planets have
active young galaxies with giant blackholes at their centers
The quasi-satellites ________ .
has stable orbits
a hypothetical body that absorbs without reflection all of the electromagnetic radiation incident on its surface.
the imaginary line forming a great circle around the Earth's surface halfway between the North and South poles
Brown Dwarfs are massive enough to have H burning, but not He burning.
93 million miles distance from earth to sun; used outside solar system and near
(astronomy) the angular distance to a point on a celestial object measured north or south from the celestial equator
Apparent motion of the stars is resulted by spin known as
What the name for power in electricity?
Dark, flat regions on the moon's surface
X rays from astronomical objects can only be detected from telescopes in space.
believed to have the formation of plates
rocky metallic objects that orbit the sun but are too small to be considered planets
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
Main Sequence
The band on the Hertzsprung-Russel diag, region of H-R diagram from upper left to lower right, includes 90% of stars, that are young and fusing hydrogen.
no force in the universe can counteract the gravity of a black hole so its core must continue to collapse towards 0 radious and infinite density forming a
Measure of galaxy clusters
white dwarf supernovae, tully-fisher relation
The amount of matter contained in a given object
shapley, in order to understand shape of our galaxy used:
globular clusters
1 AU
The semi-major axis of earth's orbit is?
which planet does the Great Dark Spot belong to?
his theory helped explain why the sun and stars move across the sky E to W
neutron star
formed when a medium sized star dies
a year
period of one orbit around the sun
Plate Tectonics
help the earth mask and recuperate from meteorites, etc.
when light elements were created
during the big bang
the alignment of two bodies in the solar system so that they appear in the same part of the sky as seen from Earth
Surface of Sun, from which we see light and other forms of electromagnetic energy coming from. T = 5800 K, around 500 km deep
Solar system
sun and all bodies traveling around it
big bang
the initial explosion that resulted in the formation and expansion of the universe
solar eclipse
Occurs when the moon passes between earth and the sun, blocking the sunlight from reaching the earth. It occurs during a new moon phase and is very rare.
The laargest structures in the universe are the
walls and voids
Measuring at which frequency a star is the brightest allows astronomers to determine..
a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space.
What are the four largest Moons of Jupiter called?
Galilean Moons
B. five or less
The distance between adjacent galaxies in a typical cluster is about ________ times the size of a typical galaxy.
A. two or three
B. five or less
C. ten to twenty
D. a hundred
E. a thousand
absolute magnitude
The apparent brightness of a star if it were viewed from a distance of 10 parsecs (32.6 light-years).
the explosion of a high mass star when it runs out of fuel
Chandrasekhar Limit
Mass between a white dwarf and neutron star is 1.4 solar masses
a large amount of gas and dust in space, spread out in an immense volume
the ____ of the Earth is 23 degrees. This tilt affects direct and indirect rays of the Sun on places in the World.
Radiaton dominated universe
the opaque universe that existed for 300,000 years after the big bang
Big Bang Theory
point at which expansion of universe began expanding
astronomical unit
a measurement for SS distance based on the distance from earth to the sun
Circular Velocity
the orbital velocity need to keep an object moving in a circular orbit
radius of the Galatic Halo of the Milky Way
65,000 ly
right ascension
angular distance of a body along the celestial equator from the vernal equinox eastward to the point on the equator nearest the body. right ascension is analogous to longitude in the terrestrial coordinate system
giant star
a very large star, much larger than the sun
Objective lens or mirror
In a refracting telescope, the long-focal length lens that forms an image of the object viewed; lens closest to the object. In a reflecting telescope, the principal mirror that forms an image of the object viewed.
The Amazonian Era
the current age that began around 2 billion to 3 billion years ago.
"3rd age"
What is a light year?
Ly, intersteller distances are to large for A.U
Protostar continues to shrink until at ______ times the size of the Sun its surface temperature is______K and its core is at T=?
10 times
T=5million K
What discovery did the Magellan spacecraft make about the recent geological history of Venus?
The Magellan spacecraft discovered that Venus has a very dry hot climate due to shrouded clouds made of sulfuric acid and a volcanically active surface.
Venus turned itself inside out,due to volcanic changes
New Moon
the point at which the moon is not reflecting any light that can be seen by the observer.
on a h-r diagram where on the main sequence would we find stars that have the greatest mass?
upper left
lighthouse model
beam sweeps across earth and we see as pulsar, period of pulses os the stars rotation period
frost line
The frost line is the boundary in the Solar System beyond which ices can condense, while only metals and rocky particles can condense inside of it. It is located between 3-4 AU from the Sun. Terrestrial planets form from the accretion of rocky and metallic particles. Jovian planets start out with such a core and then accrete lots and lots of icy particles. They can get 5-10 times more massive than the terrestrial planets in this way. When they get to that size, their gravity is strong enough to pull in additional hydrogen and helium gas from the Solar Nebula.
Saturn's tilted axis causes seasonal ______.
variation (some storm components may be related to ring shadows)
Relationship between Photons and Wavelength
the shorter the wavelength, the higher a photon's energy.
Kepler's first law
the orbit of a planet around the sun is an ellipse with the sun at one focus
About 2/3 of all chemical elements have been observed in solar spectrum. The elements other than hydrogen and helium observed in the solar spectrum:
were produced in other stars
Consider the four stars shown following. Rank the stars based on their surface temperature from highest to lowest.
red supergiant star
orange main-sequence star
blue white dwarf star
highest: blue white dwarf star
orange main-sequence star
lowest: red supergiant star
what is an astronomical unit?
the distance between the sun and the earth
three ways the sun affects the Earth
provides heat and light, gravity affects the tides, and holds Earth in orbit
What are light, heat, and ultra violet radiation and what are they produced by?
types of energy produced by stars
Where do full moons occur?
On the opposite side of the Earth from the Sun
What is happening when two plates are smashing into one another?
Subduction causes mountains to be built up; earthquakes and volcanoes may also occur.
The wavelength of the emission or absorption lines depends on
What atoms are molecules are found in the object under study
At what phase would you expect to find the most intense tides?
D. both new and full Moons
At what phase would you expect to find the most intense tides?
A. new Moon
B. first and third quarter
C. full Moon
D. both new and full Moons
E. Moon phases are not affecting the tides
The diameter of a typical neutron star of 1 solar mass is predicted to be approximately
that of an average city, a few kilometers.
So what exactly happens to a low mass star when it goes off the main sequence?
It becomes a red giant when the hydrogen was exhausted in its core, it contracted down a little bit when it stabilized for its helium burning toward the main sequence, and when the helium core starts contracting, it ascends the red giant branch for the 2nd time. The planetary nebula that leaves behind the white dwarf occurs up at the top of that 2nd red giant branch ascension. The white dwarf is supported against gravity by the degenerate electrons in it. Then, it just gradually cools off. These white dwarfs have an upper limit of 1.4 solar masses, and beyond that, they become so degenerate that the electrons are forced to combine with protons to make neutrons. You can crunch neutrons in a lot more tightly before they become degenerate. It is a neutron star's contracting iron core that creates the supernova explosion.
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