Astronomy Terms 2 Flashcards

Terms Definitions
gravity
...
Markab
Alpha Pegasus
Polaris
The North Star
epicycle
circles on deferent
new moon rises
at dawn
Granulation
Visible surface is mottled
Refracting
A___________telescope uses convex lenses to focus light.
ultraviolet radiation
electromagnetic radiation of wavelengths shorter than those of visible light but longer than those of x rays
Kepler
German, used mathematics and observations over a long period of time to figure out that the planets do not move in perfect circles around the sun, instead they move in ellipses around the sun.
revolution
Earth's movement around the sun
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
List the planets in order.
arcseconds
one arcminute divided by 60
liquid water, life
not found on Mars
Starburst
Easier for galaxies to make stars
-uses up gas quickly
-gets gas (refueled) by outside gas
what terrestrial planet has virtually no atmosphere?
mercury
ear thermometer
developed from infrared sensors developed to remotely measure the temperatures of distant planets and stars
obsidian
volcanic glass (low silica, no crystals)
Oldest known glass vessels made
1500 BC
Earth
third planet from the Sun;its atmosphere protects life and its surface temperatures allow water to exist as a solid, liquid, and gas
Mercurys atmosphere/temperature
No atmosphere
Average temperature: 440 K (167 C) (590-725 K,sunward side)
lunar eclipses
earths shadow on full moon
CMBR
(cosmology) the cooled remnant of the hot big bang that fills the entire universe and can be observed today with an average temperature of about 2.725 kelvin
Galileo Galilei
discovered Sun had dark regions (sunspots)
Meteorite
a meteoroid that does not completely burn up in the atmosphere and strikes the surface of a moon or planet
Solstices
point on the celestial sphere where the sun is either farthest north or farthest south
radiation
energy that is radiated or transmitted in the form of rays or waves or particles
Ion
- if electrons missing or added
- atoms with positive or negative electrical charge
axis
an imaginary line that passes through Earth's center and its North and South Poles
potential energy
what "E" stands for in E=mc^2
formula for speed
V=change in d÷change in time
southern hemisphere
receives more daylight during the winter solstice
Visible light
Electromagnetic radiation that can be seen with the unaided eye.
satellite
is an object that revolves around another object in space
The frequency at which a star's intensity is greatest depends directly on its
temperature
What is the main determinant of exactly where a star will be located on the main sequence?
Mass
Nebula
cloud of gas and dust in space
Metamorphic Rock
Igneous or Sedimentary rock that has been subjected to high temperatures and pressures, such as marble
spiral
the Milky Way is this type of galaxy
Phases of the Moon
position of the Earth-Moon-Sun relative to each other.
Penumbra
larger, less dark part of shadow where light is partly blocked
ecliptic
The yearly path of the Sun plotted against the background of stars.
pulsar
a source that radiates short bursts or pulses of radio energy in very regular periods
Synodic period of planet
average time between successive oppositions with the sun
comet
A loose collection of ice, dust, and small rocky particles, typically with a long, narrow orbit.
Venus
Poisonous, hot world, yet seen as our twin. 95% size of earth. Surface temperature is 880 degrees (hot enough to melt lead). 90x Earth's atmospheric pressure. Volcanic activity
equinox
"equal night" . Day time and night time are the same lenght
thermal energy
a sub-type of kinetic energy the collective kinetic energy (energy due to motion) of many particles (in a rock, in air, in water
main sequence
the stars (including the sun) that form a narrow band across the H-R diagram from the upper left to the lower right
About 10 times further from the Sun than Earth
Saturn
Where is the noon sun directly overhead(direct sunlight) at the start of each season?
23.5 degrees
galaxy
few hundred million to over a trillion stars.
Balmer series
A series of spectral lines produced by hydrogen in the near-ultraviolet and visible parts of the spectrum. The three longest-wavelength Balmer lines are visible to the human eye. (p. 111)
distance to various objects in our solar system are typically measured by
astronomical units
Light Year
the distance traveled by light in a year
The name of the grouping of stars, planets, gas, and dust that the earth is in is called the
milky way
law of universal gravitation
newton's law of gravitation, which describes how the gravitational force between two bodies depends on their masses and separation
meteor
a streak of light in the sky produced by the burning of a meteoroid in Earth's atmosphere
Barred-spiral galaxy
Spiral galaxy in which a bar of material passes through the center of the galaxy, with the spiral arms begining near the ends of the bar.
Rich
Is the Virgo cluster a poor or rich cluster?
type of star that is very small, compact dense star alsmost entirely of neutrons
neutron star
active galactic nuclei
violent events occurring in or near the galactic nucleus
Einstein Cross
appearance of 4 images of the same galaxy or quasar due to gravitational lensing
Apparent magnitude
the brightness a ster appears in our night sky
Precession
the motion of a spinning body (as a top) in which it wobbles so that the axis of rotation sweeps out a cone
Which of the following statements regarding energy is false...
energy can be destroyed
Aristarchus
the sun is much farther away than the moon and larger than the sun and earth, proposed the sun was the center but couldn't explain parallax
Where do variable stars occur when the stars in the red giant horizontal branch are under-going oscillations?
Instability strip
Lunar Eclipse
A lunar eclipse occurs when the moon passes behind the earth such that the earth blocks the sun’s rays from striking the moon. This can occur only when the Sun, Earth and Moon are aligned exactly, or very closely so, with the Earth in the middle.
red giant
a star in an intermediate stage of evolution, characterized by a large volume, low surface temperature, and reddish hue.
2 most abundant elements in the Sun are..
hydrogen and helium
light-collecting area
used to tell how much total light the telescope can collect at one time
Inertia
A body (mass) at rest or in a constant state of motion wants to stay in that state unless acted on by an outside force
Sun Spots
A dark area of the photosphere of the sun that is cooler than the surrounding areas and that has a strong magnetic field
Sidereal period
the time it takes a planet to complete a complete orbit around the sun
Dark Matter
Makes up 90% of the matter in our galaxy. Only interacts through gravity (it doesn't give off light, or form stars, or kill stars, or do anything else that could allow us to spot it).
Earths Surface is what?
Surface:
Crust - see above Oceans - lots o' water
Continents -
North Circumpolar Zone
Part of the sky in the Northern Hemisphere that contains the stars that never set from the observer's particular latitude
stage 2 of a stars life is
protostar-gravity pulls the particals of hydrogen and dust from a cloud
Compare and contrast the three different methods we discussed in detail for
discovering binary stars and extrasolar planets.
The three different methods are: Spectroscopy, eclipsing, and astrometry.
Spectroscopy is the spectrum of the two stars that shows that when one of the stars is moving away from us, the other is moving toward us.
Eclipsing we can observe the periodic dimming of the system as one star passes in front of the other.
Astrometry the motion of the stars in their orbit is in the plane of the sky.
satellites, probes, ( && ) rovers
used to collect data from electromagnetic waves that can not penetrate the earth's atmosphere. combined with cameras, telescopes, spectroscopes, ( && ) radio telescopes, they are very useful tools.
what is true of all visible stars at the north pole
thay are circumpolar
In the H-R diagram, 90% of all stars are
on the main sequence
copernicus model led to: accuracy compared to Ptolemy's, why it is important, orbital radii, kepler's third law, newton gravity
-not more accurate than Ptolemy's, but it gave a much more productive framework for thought.
-led to finding orbital radii of the planets and then to the discovery of the relationship between these radii and the periods,
-ultimately became Kepler's third law.
-Newton used discovery to come up with his universal law of gravity
what is the period of rotation for the earth
23 hours 56 minutes
D. the ejected envelope, often bipolar, of a red giant surrounding a stellar core remnant
What is a planetary nebula?
A. the bipolar jets ejected by a T Tauri variable
B. a planet surrounded by a glowing shell of gas
C. the disc of gas and dust surrounding a young star that will soon form a solar system
D. the ejected envelope, often bipolar, of a red giant surrounding a stellar core remnant
E. a type of young, medium mass star
Why is Mars a bright reddish-orange?
Because of its iron rich minerals in the soil
The greenhouse effect on Earth is caused by
C. the ground reemitting at a longer wavelength part of the solar radiation it absorbs
The greenhouse effect on Earth is caused by
A. the solar wind penetrating Earth's magnetosphere
B. convection currents in the troposphere
C. the ground reemitting at a longer wavelength part of the solar radiation it absorbs
D. exclusively the burning of fossil fuels
E. plate tectonics
Newton's Laws of Motion-
1) A body at rest or in motion at a constant speed along a straight line remains in that stage unless acted upon by an outside force (ex: rocket ship builds up speed then comes to a stop, goes to sleep).
2) A net force changes an objects momentum, accelerating it in the direction of the force.
3) Whenever one body exerts on force on a second body, the second body exerts an equal & opposite force on the first body (When someone gets mad, kicks the door, and breaks their toe).
The moon moves between the sun and the earth and throws a shadow on earth.
What happens in a solar eclipse?
why does mercury have a magnetic field?
has a huge metal core, whcih may be partially molten and convecting
The Sun's position in the Milky Way Galaxy is
in the disk of the Galaxy, inside a spiral arm or segment of a spiral arm.
greek astronomers
aristotle, ptloemaic
Power failures
solar disturbance PF
callisto
a large cratered ice ball
oblate spheroid
shape of the earth
erosion
any weather-driven process that break down or transport rock, processes that break down or transport rock, processes include glaciers, rivers, wind, ice
non green house gases
o2 and n2
corona
the outermost atmosphere of a star
Absorption Spectrum
Called a dark-line spectrum; continuous spectrum with dark lines created by selected absorption of light
Groups of stars within galaxies
Star Cluster
timing
the planet that forms the earliest captures the most hydrogen and helium gases
solar prominences
solar materials streaming into space and back to suns surface
Space probe
a rocket-propelled guided missile that can escape the earth's atmosphere
aphelion
point on the earths orbit farthest from the sun
quasar
one of over a thousand known extragalactic objects, starlike in appearance and having spectra with characteristically large redshifts, that are thought to be the most distant and most luminous objects in the universe.
mercury
made of metal and rock, large iron core, desolate cratered: geologically dead, very hot and very cold, 425 degrees celcius during the day adn 170 degrees celcius at night, has no atmosphere
spring tide
highest tidal range that occurs near the new and full moon
How old is the Moon?
3.8-4.6 billion years ago.
perihelion
point on the earths orbit mearest the sun
electromagnetic spectrum
the entire spectrum, considered as a continuum, of all kinds of electric, magnetic, and visible radiation, from gamma rays having a wavelength of 0.001 angstrom to long waves having a wavelength of more than 1 million km.
ptolemaic geocentric model
sufficiently accurate to remain in use for 1500 years
inside uranus and neptune
lower pressures mean no metalic hydrogen
Meteors
Light made by a meteoroid as it passes through the atmosphere (''shooting star'')
solstice
point or time at which the sun is farthest from the equator
Ex: summer/winter
Refracting Telescope
a telescope that uses convex lenses to gather and focus light
blue shift
when a star or galaxy moves towards us, it is blueshifting. The color of the star is moving towards the blue end of the spectrum,
white dwarf
a star, approximately the size of the earth, that has undergone gravitational collapse and is in the final stage of evolution for low-mass stars, beginning hot and white and ending cold and dark
earth is habitable
because it is large enough to remain geologically active, and it is at the right distance from the sun so oceanse could form
Heliocentric Model
Sun is at the center of the solar system and the eight planets orbit the sun
main sequence stars
the diagonal area on the HR diagram where 90% of the stars are located
astronomical unit
a unit of length, equal to the mean distance of the earth from the sun: approximately 93 million miles 150 million km.
What did Galileo discover? (5)
Jupiters 4 larges moons, planets are circular, venus has phases like earth, Moon's surface is not smooth, sun has sunspots.
Large Doppler shifts indicate ________.
a) low speeds
b) high speeds
c) low temperatures
d) high temperatures
b) high speeds
A large Doppler shift indicates the object is moving at HIGH SPEEDS.
When was the sun and other stars formed?
About 4.6 billion years ago
Which color has the longest wavelength?
a) red
b) blue
c) green
d) orange
a) red
Red has the longest wave length: remember ROY G BIV (longest to shortest and MIVUXG (shortest to longest.
origin of earths water
water may have came to earth by way of icy comets from the outer solar system
___________ has the great, dark spot on its surface.
a) Mars
b) Neptune
c) Venus
d) Uranus
b) Neptune
NEPTUNE is the planet with a great, dark spot on its surface.
Why was the atmosphere replaced with carbon dioxide, sulfur, and water?
Our gravity was not enough to hold lighter gases and they floated away.
Pluto is now classified as a ______ in our solar system.
a) terrestrial planet
b) Jovian planet
c) dwarf planet
d) comet
c) dwarf planet
Pluto is now classified as a DWARF PLANET in our solar system.
The apparent path of the Sun upon the celestial sphere is called the _________.
a) parallax
b) ecliptic
c) precession
d) declination
b) ecliptic
The apparent path of the Sun upon the celestial sphere is called the ECLIPTIC.
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