Complete List of Terms and Definitions for Astronomy Unit Test

Terms Definitions
tide ...
Albireo Beta Cygnus
Mir Russion space station
10^3 kpc 10^6 pc
paradigm a new idea (theory)
Temperature of Sun 28,800 K
Phoebe: small, dark, retrograde orbit
X ray electromagnetic radiation whose wavelengths is between that of ultraviolet light and gamma rays
Thales -Founder of greek philosophy
-Advanced the idea that an orderly universe could be understood
-First to construct theoretical models!!!!!!! HUGE
-First mathematician, and made first mathematical discovery
-believed all things are water and earth is afloat in a great sea, land is built by the accumulation of silt
spectrascope instrument that break up light.
Tangent Lines Tell you instantaneous speed
meridian imaginary half-circle stretching from the horizon from N to S
Mercury most variation in surface temperature between day/night
Rotation The spinning of the earth's axis.
NASA the National Aeronautics and Space Administration
when was the gemini space program 1962
acid a substance that releases hydrogen ions when dissolved in water
Color The reflection of specific wavelengths of light off objects.
Neptune large, gaseous planet withe rings, dark-colored storms, and eight moons; has a distinctive blue-green color
Jupiter's four moons IO, Europa, Ganymede, Callisto
earth move ___ degrees each day 1
singularity the infinitely small space that all matter in the universe existed before the Big Bang
meteoroid forms when material from the asteroid belt
Asteroid any of numerous small celestial bodies composed of rock and metal that move around the sun (mainly between the orbits of Mars and Jupiter)
Suppose that an astronomer discovers an active galaxy, and that the intensity of the radiation from the galactic nucleus fluctuates in intervals of 8 minutes. Based on her observations, the astronomer should infer that the active nucleus of this galaxy is 1 AU
Spring Tide When the tide range is greatest
Isotope versions of an element with same number of protons &different numbers of neutrons
Revolution The movement of an object around another object
speed the rate at which an object moves
formula for acceleration a=change in v÷change in t
Plains Called maria (Latin for "seas") by Galileo, made of black volcanic lava
Mars Pathfinder carried technology to study the surface of Mars including a remote-controlled robot rover called Sojourner
albedo the fraction of sunlight that a planet, asteroid, or satellite scatters directly back into space
Satellite An object that revolves around another object in space.
The VERNAL EQUINOX marks the beginning of spring
Knew the ecliptic; length of a year ecliptic
Dynamo Effect the process by which a rotating, convecting body of conducting matter such as Earth's core, can generate a magnetic field
solar wind this is caused by electrically charged particles coming from holes in the sun
Constellations Shapes early people saw in the stars they told stories about. There are 88 "official" constellations today. You need to be at the equator to see them all. Most of Western European design.
neap tide happens during first quarter and third quarter moon phases
Solar Eclipse when the moon's shadow hits the Earth
Oort cloud A spherical shell composed of somets that orbit the Sun at distances generally greater than 10,000 times the Earth-Sun distance.
Heliocentric Model Sun is centered; the Erath's rotation is proven with constructing a pendelum
protostar a contracting cloud of gas and dust with enough mass to form a star
F ring Faint narrow outer ring of Saturn, discovered by Pioneer 11 in 1979. The F ring lies just inside the Roche limit of Saturn and was found by Voyager 1 to be made up of several ring strands apparently braided together
Light-year The distance that light travels in one year; about 9.46 trillion kilometers
angular distance eas tand west of the prim meridean longitude
Celestial Equator Divides the sky into northern and southern hemispheres, just as the Earths equator divides the Earth into two hemispheres
Degree A unit of angular measure. There are 360 degrees in a circle
Astronomy the scientific study of what is beyond the earth
Once every _______ hours it take for Earth to rotate on its imaginary axis. 24
Solar Eclipse - occurrence occurs at the new moon
Hour Angle The angular distance of an object measured westward from the Local Celestial Meridian.
quasar very energy dense, 100 to 1000 times the energy of a typical galaxy
Sky map they show the entire sky as viewed from a given location at a given date and time
Path of Moon's shadow across Earth is called Eclipse track
energy flux the amount of the energy emitted from each square meter of an object's surface per second
black dwarf star that results when a white dwarf stops giving off energy
Elliptical galaxy Category of galaxy in which the stars are distributed in an elliptical shape elongated to nearly circular in appearence.
2/3 How far away is the sun from the center of the galaxy?
across motions a star has from earth due to stellar parrallex tranverse velocity
geocentric the view that the earth lay at the center of the universe and all other bodies move around it
dark matter (missing mass) the as-yet-undetected matter in the universe that is underluminous and probably quite different from ordinary matter
Big Bang Theory the current theory that describes the begining of the universe; at time zero, all the matter and energy in the universe were packed together into one immeasurably dense, hot mass, and exploded
Spring tides occur during the full and new moons, tides are very high and very low
In space, the velocity of radio waves is about 300,000 km/s
precession causes the axis o sweep out a circle, an effect due to gravitational forces
Gravitational Lensing A way to look for dark matter
-causes a background star to temporarily brighten
Right Ascension the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.
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
The impact of a large comet with Earth has been suggested to have caused the extinction of the dinosaurs. The impact site of this comet is in or near Chicxulub, Mexico
gravitational encounter one way an orbit can change through an exchange of energy in which they pass near enough so that each can feel the effects of the other's gravity
Absolute Magnitude the brightness a star would have if it were a standard distance from the earth
Solar System A star (such as our sun) with planets and other smaller bodies in orbit around the star
a measurement of the image quality due to air stability What is "seeing"?
Spiral Galaxies: Halo The halo is a spherical shell that surrounds the disk. It contains the dark matter and globular clusters: large groups of stars (Pop II) that formed before the disk of our galaxy.
Geologic history of the moon 'Geologic History' of the Moon
Formed from a collision - 4.5 billion years
Initially molten
Early period of heavy cratering - Highlands formed
Later period few impacts some very large - Maria formed
Essentially geologically dead - 3 billion years ago
Absoption Line Spectrum A series or pattern of dark lines superimposed on the continuous spectrum of a source
solar noon the point in the day when the sun is highest in the sky
Which of these objects show daily motion: The Sun, Moon, and Planets.
150 million km (1.5 x10^11m) About how long is an astronomical unit
hat do the spectra of distant galaxies collected today say about hebbles original findings it confirms that findings
An annular solar eclipse is.. a solar eclipse that occurs when the Moon's umbra does not reach Earth's surface
Newton gravityy and keplers laws, uranus and neptune Newton explained all of Kepler's laws (and much more) with a single concept, universal gravitation.
a. His theory tied together the motions of the planets with the motion of everyday objects falling to earth.
c. The theory applied to the orbit of the planet Uranus (not in Newton's life time) predicted the location of the then unknown planet Neptune to within 1º.
In the case of venus what is the inferior conjuction distance 27 X 10^6 miles
C. in our companion galaxy, the Large Magellanic Cloud Where was supernova 1987a located?
A. in the Orion Nebula, M-42
B. in Sagittarius, near the Galactic Nucleus
C. in our companion galaxy, the Large Magellanic Cloud
D. in M-13, one of the closest of the evolved globular clusters
E. near the core of M-31, the Andromeda Galaxy
On the 5-km highway of time representing the history of Earth, what length accurately reflects all of recorded human history? The last few millimeters represent all of recorded human history.
The Cassini Division is a gap in Saturn's rings caused by D. gravitational interaction with Mimas
The Cassini Division is a gap in Saturn's rings caused by A. Saturn's excess heat
B. two shepherding moons
C. Saturn's magnetic field
D. gravitational interaction with Mimas
E. the icy ring particles melting
How does the production of an iron core in the evolution of a high mass star result in
a supernova explosion? What happens in a white-dwarf supernova? 		core collapses in itself after years of nuclear reactions.
Main Sequence Red Giant Yellow Giant Red Giant Planetary Nebula Explosion White Dwarf Hydrogen to Helium No fusion in core Helium to carbon No fusion in core
What is a spectrum, what two things happen to the spectrum of an object as it is heated? A spectrum is an ordered table of emitted or absorbed radiation for a given source. When an object is heated, it emits more light at every wavelength and its peak on the visible spectrum is further to the left.
Star A has luminosity LA = 100 Lυ
and it is 1000 pc away. Star B has the same luminosity as the Sun, Lυ, and it is 100 pc away. What can you say about the brightnesses of these two stars? 		Star A and Star B have the same brightness.
corona crown
waxing getting bigger
chaos; infinite space chaos
il spazio space (astronomy)
Atmosphere Photosphere, chromosphere, transition zone, corona
refraction transparent lenses bend electromagnetic waves including light
Galaxy a collection of star systems
mars smallest of the inner planets
craters round pits on the moon
axis the earth rotates on this
Age According to the seminal research, entitled "The sun in Time" by Guinan, Dewarf et al, a solar proxy is a star that is an exact match to our sun in all physical aspects except:
Gravity force of attraction between all objects in the universe
most associated with ancient Greek world view aristotle
Erastothenes able to accurately determine the circumference of the Earth.
Earth's rotation rate 15 degrees per hour
planet A sphere that orbits a star
scattering photons are redirected in random direction
Photosphere The visible surface of the sun
taurus the Bull, a zodiacal constellation between Gemini and Aries, containing the bright star Aldebaran.
finished burning hydrogen core not luminosity class V
Titan's interior is made largely of rocky-silicate mix
F TorF: Gamma ray telescopes, such as the Chandra, are launched into space because they are dangerous to operate on Earth.
newtonian lens primary parabolic and flat secondary mirrors
Terrestrial Planets Inner planets that are smaller, denser, and rockier than the outer planets
Ptolemy successful in having people adopt his geocentric model of the universe because he gathered the best model pieces together, used the most accurate observations and he published his work in a large
13-volume series called the "Almagest", ensuring that his ideas would last long after he died (1500 years).
Retrograde Motion the aparant slowing, reversal, and then looping of a planet across the sky
convection zone outermost layer of the sun's interior
acceleration the rate velocity changes with time (vector)
Venus Planet that has the largest highlands named Aphrodite Terra
SHARED PLANET FACT: Voyager II visited them (fly-by) JupiterSaturnNeptuneUranus
revere to regard with respect tinged with awe; venerate:
Asteroids Rocks in space that orbit around the sun
Define: Eccentricity The shape of the ellipse, describing how flattened it is compared with a circle.
The event horizon is a pinpoint of infinate density and infinite smallness True
Which of these is not a medium-size moon of Saturn none
sunspots areas on the sun's surface that are cooler and less bright than surrounding areas, are caused by the sun's magnetic field, and occur in cycles
Ptolemy Facts A Greek man, wrote book called Almagest.
Believed in geocentric solar system.
Believed planets moved in little circles along a big circular path.
This planet has a thick layer of clouds that lets the sun's heat in but not out, so it is the HOTEST planet in our solar system. What's it's name? Venus
radio telescopes focuses incoming radio waves on an antenna, which absorbs ( && ) transmits these waves to an amplifier. advantages: surface does not have to be smooth. affected much less by earth's atmosphere.can be used 24 hours a day. disadvantages: poor resolution.
nebulae massive clouds of dust and gases where stars are born
constellation an imaginary pattern of stars in the sky
Characteristic of Waves wavelength- for light this determines color
frequency- for light this determines energy
Amplitude- this determines total energy
photoelectric effect the phenomenon in which the absorption of electromagnetic radiation, as light, of sufficiently high frequency by a surface, usually metallic, induces the emission of electrons from the surface.
how bright a start is depends on: temperature, distance, size
intrinsic property does not depend on anything else; ex. mass
Altitude The angle between a object the sky and on the horizon.
Hubble's Law the farther away a galaxy is, the faster it is moving away.
Light Year (LY) The distance light travels in one year.
meteor A streak of light in the sky produced by the burning of a meteroid in Earth's atmosphere.
Population 2 stars Found in globular clusters and the halo of a galaxy. Older and less luminous than Pop 1 stars. Few heavy elements. Metal poor
Semidiurnal There are two high and two low tides per day- Atlantic
Solstice Either of the two times of the year when the sun is at its greatest distance from the celestial equator.
elliptical galaxies 80% of all galaxies, most are dwarfs the super large ones eat others
light-gathering power a number, proportional to the area of the principal lens or mirror of a telescope, that describes the amount of light that is collected and focused by the telescope
Red shift An object in the universe that is moving away from earth.
Stars are born in? The densest gas in the interstellar medium.
Leap century when there is no leap year even though it's a century
black hole remnant of a star that is so dense that nothing, not even light, can escape its gravity field
Velocity of Light formula Frequency x wavelength = velocity of light
methane absorbs red why do uranus and neptune have blueish tint?
irregular galaxy A galaxy that does not have a regular shape
Celestial bodies All objects seen in the sky (the Sun, Moon, stars, and planets)
synodic month any of the twelve parts, as January or February, into which the calendar year is divided.
chandrasekhar limit an upper bound on the mass of a stable white dwarf star. It was named after Subrahmanyan Chandrasekhar, the Indian astrophysicist who predicted it in 1930. White dwarfs, unlike main sequence stars, resist gravitational collapse primarily through electron degeneracy pressure, rather than thermal pressure. The Chandrasekhar limit is the mass above which electron degeneracy pressure in the star's core is insufficient to balance the star's own gravitational self-attraction. Consequently, white dwarfs with masses greater than the limit undergo further gravitational collapse, evolving into a different type of stellar remnant, such as a neutron star or black hole. Those with masses under the limit remain stable as white dwarfs. The Chandrasekhar limit is analogous to the Tolman-Oppenheimer-Volkoff limit for neutron stars.
Doppler shift, redshift vs blueshift, wideness of spectral lines -like hearing long wavelengths of train moving away and short wavelengths of train coming closer
-redshift:moving away, blueshift: moving towards us
-wideness of spectral lines shows rotation speed of distant objects
True True or false: a day and a year on the moon are the same length
basic ideas about character of universe plays according to rules (Eienstein's General Theory of Relativity) that are very different from our everyday experience
-space is "warped" by the presence of matter
Explain how Galileo's observations of the moons of Jupiter contradicted the geocentric model. -He observed that Jupiter had moons orbiting it, like we have our own, so this proved that the Earth was not the center of the universe because otherwise the moons of Jupiter would be orbiting Earth and not Jupiter.
because the moon revolves around Earth Why do phases of the moon occur
gravitational force increases as the mass of an object `increases of as the distance between two abjects decreases
moons larger in mass than murcury none. but there are 2 larger in radius
. What effect does the Greenhouse Effect have on the surface environment of Venus? It has raised the surface temperature by hundreds of degrees Celsius.
The moon, as viewed from Earth, drifts through the constellations at the rate of: (a) about 1 degree per day. (b) about 13 degrees per day. (c) about 13 degrees per month. (d) none of the above, the moon doesn't drift through the constellations at all. (b) about 13 degrees per day
How does the light curve for both Type I and Type II? Look at Power 21 slide 11
Things that saved the Nebula Hypothesis -We discovered there is quite a lot of dust (little rock and metal) in our galaxy. The presence of dust helps us to solve the problem of how things got clumped together. How the gases came to clump together. Dust grains help the gases assemble into clumps. Instead of disbursing which is what gases do on their own.
what does an emission spectrum of a space abject tell us. what the object is made of, breack down.
What is different between a high mass star and a low mass star? The high mass star never turns into a white dwarf and a low mass star will