Complete List of Terms and Definitions for Astronomy Exam 4

Terms Definitions
revolution ...
proton-proton chain ...
mars inner planet
Red Star lower mass
Newton's 2nd law F=MA
rotation a single complete turn
Eccentricity strange and unconventional behavior
Jupiter contains a "great red spot"
_____ wavelengths have lower energies longer
EM force interaction between charged particles
heliocentric sun-centered model of the universe
Project Gemini During_________teams of astronauts orbited Earth to practice skills that would be needed to land on the moon. This was the second step in trying to reach the moon.
granulation Bubbling pattern due to solar convection.
synodic period the interval between successive occurrences of the same configuration of a planet as seen from earth
pixels short term used for picture elements
Density how highly packed a substance's molecules are; the mass of an object divided by its volumn
how fast does the wave travel speed
Theory Explanation based on many observations during repeated experiments
aristotle believed in geocentric universe, knew earth was a sphere
Great Red Spot Giant storm on Jupiter
Doppler Effect • Relative motion between observer and source causes an observed change in frequency and/or wavelength.
o Phenomena is common to all waves.
o But for light is subtly different and for sound.
• Motion toward - blue shifted (higher frequency or shorter wavelength)
• Motion away - red shift (lower frequency or longer wavelength.
• (Rope swinging amp demonstration), (ambulance driving by)
weight the force of gravity on an object
What are solid objects which orbit planets called? moons
mantle under the crust, made of slightly different silicate minerals (peridotite); it is solid, but will flow slowly over long times
Equinox When the sun crosses the celestial equator. The number of daylight and night hours are the same
Chromosphere The middle layer of the sun's atmosphere
nuclear fission process that produces nuclear fission in the sun:
Highlands: old, origional crust of the moon. heavily cratered
degeneracy When particles are compressed to an unnatural state where their
pressure is not related to their temperature.
Galileo The first astronomer to look at Jupiter through a telescope and see the 4 moons orbit
Geocentric Earth centered idea of the solar system
variable star A star whose brightness changes periodically. (p. 255)
ecliptic the great circle formed by the intersection of the plane of the earth's orbit with the celestial sphere; the apparent annual path of the sun in the heavens.
Neptune Triton is the name of the moon here
Gravitational fields alterations of space due to the existence of objects having mass
light-year the distance that light travels in a vacuum in 1 year
Crater Large round pits on moon that are caused by meteors hitting the moons surface.
Elliptical Galaxy An oval shaped galaxy consisting of older stars.
stefan-boltzmann's law how rapidly energy flows from an object F=oT
Isaac Newton A scientist who showed that all objects in the universe attract each other through gravitational forces; gravity depends on the mass of the objects and the distance between them. His laws of gravity helped explain the orbits of the planets around the sun.
meteor a streak of ionization in the earth's atmosphere caused by burning debris traveling through the atmosphere
apparent brightness formula for ___ = luminosity/[(4pi) x (distance^2)]
gametes male and female sex cells (sperm and eggs respectively)
Penumbra the larger, less darker part of the moon's shadow in which part of the sun is visible
supergiant Life cycle stage of a massive star where the core reaches extremely high temperatures, heavy elements form by fusion, and the star expands.
Amplitude In a wave, the maximum deviation from its undisturbed or relaxed position. For example, in a water wave the amplitude is the vertical distance from crests to the undisturbed water level
A pulsar is a(n) rapidly rotating neutron star, emitting beams of radio energy and sometimes X-ray and visible
energy.
neap tide an unusually low high tide and unusually high low tide that occur when the tidal forces of the Sun and Moon act at right angles to one another
Hr diagram it shows how the absolute brightness and the temperature are related.
nucleus The central core of an atom containing protons and neutrons; carries a positive charge
light In a supernova type Ia, most of the total energy emitted is in the form of...
Solar system a star and all the material which orbits it including planets and moons
Light Year the distance that light travels in one year
Gamma Rays The smallest and most deadly part of the spectrum. Can cause damage to humans if exposed.
kuiper belt region of the solar system, beyond the orbit of Neptune (30 AU) containing many icy planetismals and cometary nuclei
according to the theory of general relativity, gravity is caused by ___________ curvature of space-time
nuclear fusion when h2 combines to form helium and energy
Zeeman effect a splitting of spectral lines in the presence of a magnetic field.
International Space Station: Date An orbit assembly began in 1998
dark energy A mysterious force that appears to be causing the expansion of the universe to accelerate.
The Earth Seasons Caused by the Earths 23.5 degree tilt
Comets Orbit the sun in a much longer and narrower orbit than the planets
Redshift A shift of spectral lines in the light of an object toward the red. Means object is moving away from the Earth(most common shift)
Contrast visual binaries, spectroscopic binaries, and eclipsing binaries. Which can be used to determine stellar diameter? Visual binaries are detected by looking through a telescope and seeing that, what looked like 1 star to the unaided eye is in fact 2. Spectroscopic binaries are detected by changing doppler shifts in the stars due to their orbits around their common center of mass. Eclipsing binaries are ones where their orbits are lined up so that they cross each other in our line of sight. Most of the time we see the combined light of both eclipsing binaries, but when one passes in front of the other we see a dimming down of the combined light. Stellar diameters are determined using eclipsing binaries because the length of time it takes for one to cross the other is the length of time we see the dimming for.
average distance between sun and earth 93,000,000 (93 million) miles
spiral galaxy formation gas & dust clouds & stars combine, formation is slow, fast rotation causes gas clouds to flatten
H II Regions A region of interstellar gas that has been ionized by UV radiation from nearby hot massive stars
properties of matter all matter takes up space and exhibits gravity, weight, mass, volume, density
Wave Lengths that are not absorbed by the earths atmosphere Radio, Visible light
What do gravity anomalies indicate? Indicate lack of isoctatic adjustment, stiff mantle.
Line of Nodes 1. a line defined by the intersection of two orbital planes.
2. the line defined by the intersection of earth's equatorial plane and the plane of the ecliptic
Moon Synchronous Rotation Moon rotates exactly 1 time in 1 orbit, sun is up for 14-15 days on moon (up 2 weeks, down 2 weeks)
Differential rotation The rotation of a star or planet at different speeds at its equator.
What was the date of the first lunar exploration? July 20, 1969
they have different chemical compositions Stars on the main sequence have different luminosities because:
spin (of an electron or proton) a small, well-defined amount of angular momentum possessed by electrons, protons, and other particles
circumpolar stars stars that can be seen at all times of the year and all times of night.
scepter a rod or wand borne in the hand as an emblem of regal or imperial power.
the interior of jupiter primarily consists of what? gaseous and liquid hydrogen and an ice-rock core
the distance light travels in a year A light year is defined as
what is newton's 1st law? momentum of an object does not change unless acted upon by a force. an object at rest will remain at rest, and an object moving in a straight line at constant speed will not change its motion, unless an external force acts on it. a body in motion will remain in motion in a straight line until acted upon by force.
Explain the Co-Creation theory of the Moon's formation in a sentence or two. Explain why this theory has problems explaining the rock/metal ratio in the Moon and the lack of volatiles in the Moon compared to the Earth. The Co-Creation theory states that the Earth and Moon formed as an orbiting binary planet system, which explains the closeness in mass. The problem with this theory is that if they were both formed at the same time from the same materials, then they should both have the same basic properties and metal to rock ratio, which is not the case. In addition, the Moon lacks nearly all volatiles that the Earth has, with no indication of a random heat source that effected the Moon but not the Earth.
Kepler's third law of planetary motion all of the motions of the planets relate to one another
Where and in what direction is the right ascension counted? Right ascension counts from the vernal equinox eastward.
any object smaller than 100 meters in size The break point between asteroids and meteoroids is:
When an electron in an atom goes from a higher energy state to a lower energy state, the atom emits a photon of a specific frequency.
A nucleus that contains two protons and one neutron is: (a) 3H (also known as "tritium"). (b) 3He (a stable but rare form of helium). (c) 6Li (an isotope of lithium, the element that has an atomic number of three). (d) impossible (b) 3He (a stable but rare form of helium).
variable changeable
Arcturus Alpha Böotes
spiral density wave ...
Acceleration change in velocity
abundant elements Hydrogen and helium
Ursa Major name this constellation
Jupiter moons 4 Galilean moons
electron a negatively charged subatomic particle usually found in orbit about the nucleus of an atom
sunspots low-temperature regions in the photosphere made by strong magnetic fields pushing away hot plasma
jupiter's interior rocky core,
metallic hydrogen
(currents here produce
the magnetic field)
expanding average distances between galaxies increase with time
satellite Any object that revolves around another object in space.
moon the different satellite (object) that revolves around a planet.
10 km typical size of comet's nucleus
Sun Shines by: -Turning mass into energy
diorite igneous plutonic rock with medium silica sontent
Ellipse Elongated, closed curve that describes Earth's yearlong orbit around the Sun.
neutron star remains of high mass stars
Mercurys interior Interior - cool, iron-rich core
The closest planet to Earth is? Venus
Michelson Morley Experiment most famous failed experiment, disproved the existence of aether
Galileo Galilei discovered Venus had phases like moon
spiral galaxies galaxies that have spiral arms (consisting of bright stars, dust, and gas) that wind outward from the center; ex. Milky Way; can be normal or barred
Solstices point on the celestial sphere where the sun is either farthest north or farthest south
Meteoroids Material in space; smaller than minor bodies
Rosch Radius An imaginary sphere around planets that when an object touches it, it will be sucked in by gravity.
Moons caused by collisions and captured by planets
metamorphic rock formed when igneous and sedimentary rocks are heated and/or compressed
Dust Grains carbon and silicate dust between stars
Big Bang 14 billion years ago, still expanding
parallax apparent change in position of an object when you look at it from different places
"The Scream" *Edvard Munch
*road with railing, not a bridge
*harbor with ships, city with spires & domes of Oslo (Christiana)
*sunset view to the southwest (TxSt group found site)
*"blood red" sky
Tilt move sideways or in an unsteady way
Johannes Kepler discovered three laws of planetary motion
Uranus and Neptune are made mostly of hydrogen compounds
Aurora Caused by solar flare. is a natural light display in the sky, particularly in the polar regions, caused by the collision of charged particles directed by the Earth's magnetic field. An aurora is usually observed at night and typically occurs in the ionosphere.
Protostar A contracting cloud of gas and dust; the earliest stage of a star's life
characteristics of the moon temperature, atmosphere, rotation and revolution
Polaris the star that is always directly above the north pole
Synchronous rotation The moon's rotation and revolution are the same
Surface/ Appearance of Jupiter "Surface"- upper cloud layers; rotation causes bands; cloud layers typically bright yellow, orange, and red; the great red spot- hurricane stable & always present
Big Bang Theory (cosmology) the theory that the universe originated 20 billion years ago from the cataclysmic explosion of a small mass of matter at extremely high density and temperature
Spectral types - G 0 through 9
White to Yellow
5,000-6,000 K
prominence A huge, reddish loop of gas that protrudes from the sun's surface, linking parts of sunspot regions.
temperature is the average kinetic energy of the many particles in a substance, not the sum of all their energies.
Comet a chunck of frozen matter that orbits the sun in very long elliptical paths, some visit the sun once
Summer Solstice July 21st, Sun reaches it's lowest point. Least amount of daylight.
Benedict a total solar eclipse so impacted him that he started his still famous work
isotopes Atoms that have the same number of protons but a different number of neutrons. (p. 105)
event horizon the escape velocity is greather than the speed of light
Polar Orbit An orbital path that moves at right angles to the rotation of the Earth
Autumnal Equinox it is the day where the northern hemisphere starts fall
scientific method the method of doing science based on observation, experimentation, and the formulation of hypotheses that can be tested
local group a group of about 30 galaxies that includes the Milky Way
lunar eclipse the blocking of the moon from the earth's shadow
type of star that creates a pulsating radio source, rapidly rotating star, located in the crab nebula pulsar star
aberration of starlight the slight shift in the observed direction to a star, caused by earth's motion perpendicular to the line of sight
irregular cluster (of galaxies) an unevenly distributed group of galaxies bound together by their mutual gravitational attraction
solar eclipse When the moon comes between the Earth and the sun and covers the sun
Doppler shift Can be used to detect binary stars, and also determine the SPIN of a star: by the width of the spectral lines.
Astronomical unit the distance from the earth to the sun
What is the most accepted theory of moon formation? collision-ejection theory
Extrasolar planets detected using Doppler Effect tend to be Large and close to the star
Degeneracy pressure in stars Comes from electrons, Things that are held up by degeneracy pressure have a strange property -the more massive they are, the smaller they are. electrons or neutrons are being squeezed together.
Black Hole an object so dense that we can no longer receive any radiation from it
Red giant the state of a star when fusion has exhausted almost all its hydrogen supply and made it into helium; they are reddish in colour
The Expanding Universe * In the 1920s, Hubble noticed all galaxies are moving away from the Milky Way (except those in our local group).
* The further away galaxies are, the faster they are moving away from us.
* This led to Hubble's law: Ho=v/D.
* Can also use D=v/Ho to get distance once you know Ho.
* Best value is Ho=72 km/s/Mpc
* Hubble's constant also contains the age of the Universe.
* Implies an age for the Universe of 10 billion years.
Periodic Table of Elements Complete list of familiar items such as carbon, oxygen, silver, lead
acceleration of gravity acceleration of a falling object in m per sec
Alpha Centauri system the closest star system to the Sun; a triple star system; includes Proxima Centauri
Future for Life on Earth? Sun gets brighter as it ages
Runaway greenhouse in
100 million years (P)
3-4 billion years (O)
Red Giant Phase
Bohr theory of an atom atom has a nucleus with pos/neg neutrons held together by electrons revolving around nucleus (chemical composition of a star)
what is the tempature of the energy of the background radiation from the big bang -120 digrees c
From inside out, which is in the correct order for the structure of the sun? 1. core
2. radiative zone
3. convective zone
4. photoshere
5. chromosphere
6. corona
7. sunspot
8. granules
9. prominence
the moon is unique in that it orbits near its planet's orbitla plane
we see white light when the basic colors are measured in equal proportions
stage 3 of a stars life is hydrogen and dust heat upfrom banging against each other,it creates nuclear reactions. this is the begining of a star
Which layer shines faintly but extends for millions of miles? Corona; during a solar eclipse it looks like a jagged white halo around the sun
Why does radiometric dating only provide a lower limit to the age of the Earth? How do we know the interior structure of the Earth?
What is the most important reason why an
ice moon is more likely to be geologically
active than a rocky moon of the same size? 		tidal heating can melt internal ice, driving activity.
What other characteristic of a star can we deduce from the star's placement on this diagram? Radius, r (usually in terms of solar radii, R )
The "event horizon" of a black hole is defined as the radius at which even light cannot escape
Following this line of thought, why do scientists think the Universe was lifeless for at least about 2 billion years? Bc in the early universe there were no heavy elements (H, He, Li)
Uranus looks blue
right side cold
4 galilean moon jupiter
pulsars spinning neutron stars
two countries Haiti, Dominican Republic
Mercury 870- -297 degrees F
advantages/disadvantages of releflectors mirrors, large size
Astronomy The study of the universe
asteroid space rock larger than 1km
newton astronomer(s) that could measure the effect of gravity and proposed it is what keeps the planets in orbit
RR lyrae brightness changes rapidly over hours
what limits a telescopes resolving power diffraction
gravity the attractive force between objects; its strength depends on their mass and the distance between them
clavius german, astronomer to the pope gregory, created the gregorian calendar which made the leap year cycle more accurate
galaxy great island of stars (millions, trillions)
Eratosthenes determined the size of the earth
Astrolabe instrument used to determine latitude by measuring the position of the stars
Aries the Ram, a zodiacal constellation between Pisces and Taurus
Terrestrial planets (smallest to largest radius): mercury, mars, Venus, Earth
wavelength distance between adjacent peaks of the electric field
what do asteroids and comets orbit? the sun
where do meteor showers occur? the earths atmosphere
potential energy energy stored for later conversion into kinetic energy; includes gravitational, electrical, and chemical ....... ........ .
Kepler (A.D. 1609) Stated Three Laws of Planetary Motion!
Waxing ______ moon appears to be getting bigger
orbit The path one object takes around another
what color would the spectroscope show if the stars were moving away red
Titan moon of Saturn;
largest moon in solar system
pluto 9th planet? small rocky/ice body with companion moon charon both orbiting a point in space, only planet not visited by a probe, has unusual orbit not in same plane as other planets and very oval which at he same time brings it closer than neptune
Spring Tides Unusually high tidesOccurs with new moon and full moon.
diamond ring effect a phenomenon, sometimes observed immediately before and after a total eclipse of the sun, in which one of Baily's beads is much brighter than the others, resembling a diamond ring around the moon.
True or False: The Galilean moons are very similar to the terrestrial planets because their orbits have low eccentricity. True
Celestial sphere an imaginary sphere of which the observer is the centre on which all celestial objects are considered to lie
Massive 1.3-7.5M Sun (or a little higher) just before death.
Force of Gravity Force = Gravitational constant times (product of two masses divided by the distance squared)
Radius of the sun 100 earth radii (696,000 KM)
What are greenhouse gases? water vapor, H2o and Co2
creationism not a science because it is not falsifiable and does not seek to explain natural phenomena
what is a comet made of? ice and dust
suspected black holes are detected as what in a binary star system observed singularities
oribt the path an object takes as it revolves around another object
hydrostatic equilibrium The balance between the gas pressure (outward force of gas molecules) and the force cased by the weight of material above (gravity)
perigee The point closest to Earth in the orbit of a body circling Earth. (p. 37)
celestial equator the great circle of the celestial sphere, lying in the same plane as the earth's equator.
brown dwarfs never had enough mass to become a star
Using the modified Keppler's law M=A^3/P^2, find the mass of a black hole given we see a star orbit it once a year at a distance of 10 AU 1000 thousand solar masses
The largest thunderstorm on Saturn is called the dragon storm
Absolute Magnitude Dates back to the 19th century, the magnitude that a star would have if it were viewed from a distance of 10 parsecs (32.62 light years) from the earth
white dwarf supernovae white dwarf ejects some mass, white dwarf accretes matter again, if it gains enough mass it hits 1.4msun, temp rises, carbon fusion begins "carbon bomb" white dwarf explodes.
globular clusters round; 10,000 to 2 mill stars; in halo: nucleus of milky way; population II stars; only red, orange, yellow in nucleus/halo; ALL old, VERY; ages=10-13 bill yrs; primordial gas: Hydrogen, Helium, almost no metals
Characteristics of the crust The outermost layer, thinnest, least dense, mostly ignous rock.
triple alpha process The fusion process that turns three helium nuclei into a carbon
nucleus.
Conjunction- Event in which a planet and the Sun line up in our sky,
Every location has a unique address which includes two numbers:________________ latitude and longitude
Dried Rivers What could have once supported life on Mars
partial lunar eclipse part of moon passes through earth's umbra
annular eclipse an eclipse of the sun in which the moon is too distant to cover the sun completely so that a ring of sunlight is seen around the moon at mideclipse
Law of Universal Gravitation Newton's Law with which he succesfully derived all of Keplar's Law
The region(s) around Earth where the magnetic field traps charged particles is(are) the van allen radiation belts
seasonal labels refers to the portion of the sky which is in upper transit around 8m local time; hold page up looking south
absolute brightness the brightness a star would have if it were at a standard distance from Earth
Geocentric model of the Universe earth at the center, motion circular
8.0- 25.0 Mass At what main sequence mass is a star likely to leave behind a neutron star:
very luminous Most of the stars we see in the sky are
Challenges to ss theory: progression of planet densities and composition -inner solar system: solid rocky surfaces with metal interiors, few or no moons and no rings
-outer solar system: made mostly of hydrogen, helium and hydrogen compounds, rings, extensive system of moons
Binary Stars Give us MASS. There is no other way to get this. Over 60% of stars are binaries. Eclipsing stars also gives us size (their radii) and distance.
Stars range in luminosity from ? to ? 10^-4 to 10^4 L
Faster fuel usage means... a high mass star burns out faster than a low mass star
The "butterfly diagram" is a graph of latitude of a sunspot vs. time
How are reflecting and refracting telescopes different? Reflectors are made with mirrors and refractors with lenses. Most telescopes today are reflectors because it is difficult to get the lenses of a refractor perfectly smooth on both sides and to have them big enough for today's needs without them sagging.
What is a spring tide a tide that occurs when the moon is new or full
Which of the following statements about an ellipse is not true? The focus of an ellipse is always located precisely at the center of the ellipse.
True or False. A White Dwarf uses nuclear fusion to generate energy. False. White Dwarfs have exhausted their supplies of hydrogen and helium fuel and instead converts gravitational energy into thermal energy, and its interor becomes very hot; but it cannot get hot enough to ignite carbon fusion.
When an electron falls from an orbit the energy lost by atom goes into emitting a photon
What is a total solar eclipse? All of the sun is covered by the moon
Origin of the 21-cm line of hydrogen The energy of the H atom is higher when the spins of the electron and the proton are parallel than when they are antiparallel
-When the spins flip, microwave radiation is emitted at a wavelength of 21 cm
Why did a major planet not form out in the Kuiper Belt? Some may have, but they have since migrated to orbits nearer the Sun