Astronomy 23 Flashcards

Terms Definitions
outer planets
heavily cratered
a flattened circle
-above photosphere
-the structure reflects the sun's magnetic field
Shape of plaents orbit
The Drake Equation: .fi.fc.L
the smallest and hotest star
meteroid which enters earth's atmosphere and burns up as a "shooting star"
light-colored high-pressure bands in Jupiter's atmosphere
a burning ball of gas
What college did Newton attend?
partly but less than half illuminated
International Astronomical Union
1928, established 88 constellations
Hertzsprung Russell diagram regions
Main Sequence
--Horizontal Branch
--Red Giant Region
--White Dwarf Region
Variable stars
stars that change in magnitude
ejecta shot out along specific direction
partial solar eclipse; the lighter part of the shadow
published the Sun-centered model of the solar system in 1543.
how many moons does uranus have
Protoplanets are moon-sized or larger planetary embryos within protoplanetary discs that have undergone internal melting to produce differentiated interiors.
C (speed of light)=
3 X 10^5 km/sec
The outermost largest layer of the sun's atmosphere; it extends millions of kilometers into space and has temperatures up to 2 million K.
The study of the moon,stars,and other objects in space
"power"; rate @ which star radiates energy; like wattage rating for lightbulb
outlawed substances that deplete the ozone layer in order to recover the ozone layer
montreal protocol
unit of measurement based on the distance from Earth/ equal to 3.3 light years.
All the stars, the planets, dust, gases, and energy.
What motion determines doppler shift.
the motion towards/away.
What planet is 8th from the sun?
vernal equinox
(astronomy) the equinoctial point that lies in the constellation of Pisces
Space-Based Telescopes
Hubble space telescope, HST., Webb Space Telescope - Launch in 2012, Specific Wavelength Space Telescope: -infrared, ultraviolet, gamma cosmic.
Who first saw Jupiter's large moons and that our moon was a landscape and not something like Aristotle's quintessence?
nuclear fusion
the process that "ignites" a star
An imaginary line that passes through earth's center and the north and south poles.
Spiral Arms
Regions of the densest interstellar gas where star formation is taking place
Amount of time to complete one revolution
Super Nova
release gasses to form nebulas. super nova's, depending on mass can create neutron stars or black holes
absorption spectrum
cool gases absorb this set of frequencies
There are thought to be___of___in the universe
billions, galaxies
the spinning motion of a planet about its axis
the rotational axis is tilted at _____ degrees to the ecliptic
the daily event of the sun rising above the horizon (right as the tip of the sun shows)
Oort Cloud
A region surrounding the solar system where millions of comets are thought to come from.
Newton's First Law
Object moves at constant velocity unless a net force acts to change speed or direction
dark energy
carries energy, and exerts an overall repulsive effect on the universe, speeding up the expansion of empty space
solar system
sun, planets, and all the other objects that revolve around the sun
Dependent variable
Factor that can change if the independent vaiable is changed
the gas that most stars are composed of
the path of an object around another object
cluster of galaxies
a collection of galaxies bound together by gravity. Small collections are generally called groups, while larger ones are called clusers.
amino acids
what important molecules of life did Miller and Urey brew up?
spring tide
an especially high tide that occurs when the sun, moon, and earth are nearly in a line
The diameter of our Sun is approximately ____________ km.
1.4 million
is the point, in an elliptical Earth orbit, of greatest distance from the Earth.
the point in space when the earth is closest to the sun
Local Group
group of galaxies, at least 25 of which are known, that included the Milky Way
Time Zone
One of 24 divisions of the Earth's surface separated by 15 degrees along lines of constant longitude with allowances for some political boundaries
the moon within a gap of saturn's ring
pan, daphnis
the length of time it takes for a planet to make one complete revolution around the Sun
The point on the bottom of the sky directly under our feet.
how are you able to produce heavy elements?
Helium Capture.
Focal length
the distance from the center of the lens to the focal point
the study of the origin and future of the universe
observable universe
portion of the entire universe that we can potentially observe therefore consists only of objects that lie within 14 billion light years of Earth
Neutron Star
First discovered by Jocelyn Bell as a pulsar (rapidly spinning neutron star)--crab pulsar spins 33x a second. Theory by Tommy Gold
terrestrial planet
planet with a solid, rocky crust; more dense; Inner planet. Mercury, Venus, Earth, Mars
circular speed
the speed that causes an orbiting body to have a circular orbit rather than an elliptical one
Thermal Radiation Spectrum
No real object emits perfect radiation spectrum but familiar objects, sun/planets/rocks/humans emit light that approximates thermal radiation
Moving particles apart and bringing them together
random thermal motion
shockwaves from supernovae
star clusters
all born at same time out of same cloud
The discovery that the universe is expanding faster today than in the past was possible because of observations of
Type Ia (white-dwarf) supernovae
Surface Features of Mars
1. Olympus Mons- Shield volcano 2. Valles Mariners- Enormous valley along equator 3. Polar Icecaps- frozen water and CO2 4. Evidence of past water flow 5. Red dust on surface- iron oxide (rust)
• These are true
 Venus is more massive than Mercury., Venus has a thicker atmosphere than Mercury, Venus is larger than Mercury
Who discovered the cosmic background radiation?
Robert Wilson and Arno Penzias
asymptotic giant branch (AGB)
the portion of the H-R diagram occupied by enormous, cool stars with helium-burning shells
occurs during the time of a new moon. when moon passes directly between sun and earth
solar eclipse
About how hot is the core of the Earth?
6500 K.
A galactic Nova involves what type of star: A) T Tauri, B) Cepheid, C)
Massive supergiant, D) White Dwarf XXX, E) Neutron Star
D) White Dwarf XXX
What areas of the EM spectrum are absorbed by our atmosphere?
visible, IR and Radio
one star has a temp of 30,000 k and another has a temp of 6,000 k. compared to the cooler star, how much more energy per second will the hotter star radiate from each square meter of its surface?
625 times
what is the distance from the su to neptune
2.8 billion miles
What is Mercury's interior made up of?
Dominated by a large, iron-rich core.
phase of the moon
the shape of the lighted part of the moon as seen from earth
What is parallax shift.
1/2 of the stars shift back and forth in degrees
Explain why we think that ring particles must be replenished over time. Will the Jovian planet rings always look the same?
New particles are continually supplied to the rings to replace those that are destroyed. These new particles must come from a source that lies in each planets equatorial plane. The most likely source is numerous small moons moons the size of gap moons ( see Figure 11.34) that formed in the disks of material orbiting the young jovian planets. Like the ring particles themselves, tiny impacts are gradually grinding away these small moons, but they are large enough to still exist despite 4.5 billion years of such sandblasting. No
How long does it take for Earth to travel around the sun?
365.25 days, or a year.
Newton's First Law of Motion
An object at rest or in motion will remain at rest or in motion unless acted upon by a force
newton's second law of motion
newton's first law of motion
Stars and the Sun
A star is a hot ball of gas that can emit light, hte reason for this is that the center of most stars are hydrogen atoms, they are being converted through nuclear fusion reactions into helium atoms and are made of protons. The reaosn for this is that Sun atoms are a huge amount of energy.
What is the distance to the nearest stars? And what are the names of those stars?
25 trillion (??);
Alpha Proxima and Alpha Centuri
The fact that so many of the planets find ~1rbiting other stars are so much more massive than the planets in our
solar system probably is a sign that
Our techniques for finding planets can currently only find these kinds of planets
consider an atom of gold in which the nucleus contains 79 protons and 118 neutrons. What is its atomic number and atomic weight?
The atomic number is 79, and the atomic weight is 197.
Hercules Cluster
newton's was a
Au of Neptune
diameter of sun
864,000 miles
standard unit of energy
spectrum produced by galaxy
Sunspots are
cooler than their surroundings
something that orbits a planet
The next-closest galaxy to ours
when one body rotates around another
Most Volcanically Active Jovian Moon, also innermost jovian moon, silica rock surrounding molten iron core
Unique features: Great dark spot; similar to the great red spot on Jupiter
Scientific thinking developed only in the past few decades
brahe's assistant; said all planets revolve around sun in elliptical orbit and the sun is not in the exact center
layer of atmosphere closest to ground
* earth centered universe and equent
smaller cluster, contains both high and low mass stars, contains multiple generations of star formation, has much heavier material
Geocentric- earth is center
Copernicus (1540 AD)
Natural Satellite
Satellites that revolve around larger planets.
a large, irregular shaped rocks that orbits the Sun
a small, solid particle that travels through space.
Friedrich Bessel
Became first to measure stellar parallax, measured annular parallax for 61 Cygni in 1838
Light year
distance light travels in one year
largest planet and fifth planet from the Sun; has faint rings, seventeen moons, an atmosphere formed mostly of hydrogen and helium, and its surface has continuous storms. Roman supreme god.
Isthar Terra
highland on Venus that contains Maxwell montes
the great circle on the celestial sphere whose plane passes through the sensible horizon and the center of the Earth
whick kind of interior seismic wave does propagate through fluids and is faster
Neutron Stars
The remains of high mass stars
A huge grouping of stars, solar sytems, gases, and dust held together by gravity
astronomical observatories
places used for observing the skies
What is the diameter of Saturn
75,000 miles
H-alpha line
The most prominent spectral feature due to hydrogen at visible wavelengths (wavelength = 6563 angstroms)
Where light is brought to converge,an image is formed
Brown Dwarfs
Like giant planets but aren't orbiting other stars
Suppose you built a scale-model atom in which the nucleus is the size of a tennis ball. About how far would the cloud of electrons extend?
Several kilometers.
parallel lines that are drawn east and west on the globe measure
look back time
time since the beginning of universe
pair production
In the early universe, matter and anti-matter were being created equally out of the radiation
Valles Mariners
Enormous valley that runs along the equator of Mars (Grand Canyon)
rene decartes
proposed the sun and planets formed when a large vortex contracted and condensed
A large star in its death that suddenly explodes ,increasing many thousands of times of brightness.
elliptical orbit
revolving around an object in an oval-shaped path like a flattened circle
Voyager 1
flew past Jupiter and Saturn; will explore beyond the solar system as part of the Voyager Interstellar Mission; will transmit data to earth for at least 20 more years
sidereal period
true orbital period of a planet-time it takes the planet to complete one full orbit of the sun relative to the stars
when the Sun is farthest from the equator, december 22
Discovery of Neptune
because of irregularities in Uranus' orbit and the law of gravity
Jovian planets
large masses, many rings, many moons, no solid surface
Oort cloud
The hypothetical source of comets. A swarm of icy bodies believed to lie in a spherical shell extending to 100,000 AU from the sun. (p. 462)
If the moon passes through Earth’s full shadow (Umbra) we have a ________.
Lunar eclipse
(6) Why does the Earth have a hard time capturing Hydrogen while easily maintaining an abundance of gases like Carbon Dioxide?
States that about 13.7 billion years ago, the universe began with a huge fiery explosion.
the Jovian planets are still _____ and have not yet finished ______.
contracting, forming
What is the universe
the universe is everything; planets, stars, galaxies, etc.
Tilt on earths axis & the track the sun takes
Capture Theory
This theory proposes that the Moon was formed somewhere else in the solar system, and was later captured by the gravitational field of the Earth. The Moon's different chemical composition could be explained if it formed elsewhere in the solar system, however, capture into the Moon's present orbit is very improbable. Something would have to slow it down by just the right amount at just the right time, and scientists are reluctant to believe in such "fine tuning". Also, this hypothesis does not have a natural explanation for the extra baking the lunar material has received
electromagnetic radiation
general term for those waves of the electromagnetic spectrum
two moons of mars
Phobos and Deimos,
small irregular shapes,
not like our moon
more like captured asteroids.
used to designate a region of the sky (88)
The dominant component of the soil on Mars is probably
iron oxides.
Disadvantages to reflecting telescopes
part of the image is blocked
What is the closest star to our earth?
proxima centauri
evening star
Any planet visible in the sky just after sunset. (p. 30)
tropic of cancer
a malignant and invasive growth or tumor, esp. one originating in epithelium, tending to recur after excision and to metastasize to other sites.
Laboratory measurements show hydrogen produces a spectral line at a wavelengh of 486.1 nanometers (nm). A particular star's spectrum shows the same hydrogen line at a wavelength of 486.0 nm. What can we conclude?
The star is moving toward us.
source of the suns energy
fusion reaction, the fusion of hydrogen into helium
geocentric theory
The belief that the Earth is at the center of the universe.
Superior planet
a planet that is farther from the sun than the earth is
red giant
a large reddish star late in its life cycle
By what factor is the light-gathering power of the 10-m diameter Keck telescope on Mauna Kea in
Hawaii greater than an average unaided human eye, with a typical aperture diameter of 5 mm?
4 × 106 times
Neap Tides
When the Sun, Moon, and Earth form a 90 degree angle, we have tides with a minimal tidal range.
What is luminosity?
the amount of energy a star radiates per unit of time. Measured in joules
What is the 2nd stage in a star life cycle?
red giant
Edge on view of NGC 4563 shows what?
Central bulge and disk.
law of conservation of angular momentum
an objects angular momentum cannot change unless it transfers angular momentum to or from another object
a push or a pull - can be when things are in contact and over long distances
Muslim fast of Ramadan occurs
during the ninth month of a 12-month lunar cycle
Which of the following is not consistent with the major hallmarks of science?
Science consists of proven theories that are understood to be true explanations of reality.
name the colors of the spectrum in order
red, orange, yellow, green, blue, indigo, violet
mass of stars: Newton's theory of gravity, how to determine binary stars, two methods to find period, finding radii
-most direct way: use Newton's theory of gravity- find orbital period and average separation of a low mass satellite
-observing orbital periods of planets is difficult so observe orbital periods of two stars about each other
-usually we can't see both stars directly, but we can see periodic light variations due to eclipses or Dopplar shifts in the spectrum
-in eclipsing binaries-if possible measure the average orbital separation and the period-gives clear answer
-otherwise, use the Dopplar shifts of the two stars to deduce the orbital separation using the orbital velocities
-find radii from by measuring the time intervals of the eclipses and knowing the orbital velocities and separations
-very few binary stars out there
What is meant by the collecting power of a telescope?
Amount of light. Diameter increases this collecting power.
What is the range of star masses for high-mass stars?
Between 8 and 100 solar masses
compare how bright they actually are (intrinsically) and how bright they appear to be
how do we find distance for the distant stars?
• Which of the following is largest? -
size of a typical galaxy, bigger than - 1 light-year, distance to the nearest star (other than our Sun), size of Pluto's orbit
At the present time Mars has water
only as ice at the poles or below
the surface
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