Complete List of Terms and Definitions for Astronomy 115

Terms Definitions
Gene Shoemaker ??
Shortest wavelength Violet
fast differential rotation jupiter
dynamo effect magnetic field
tams terminal age, main sequence
Diameter of Earth 12,756 km
vector magnitude, unit, and direction
heat source = planet's "___________" surface
red giant a large cool star
watts What is luminosity measured in?
micrometer one millionth of a meter
Retrograde Motion planets sometimes appear to temporarily reverse their direction of motion
absolute magnitude brightness 32 light years away
solar system sun planets satellites asteroids comets and related objects that orbit the sun
Red Shift shift toward longer red wavelength
ellipse elongated, closed curve that describes Earth's yearlong orbit around the sun
Jupiters Moons Galilean Moons. Callisto, Ganymede, Europa, Io
mars. about 50k cooler than on earth
altitude the angular distance between the direction to an object and the horizon, altitude ranges from 0 for an object on the horizon to 90 for an object directly overhead
Ptolemy Alexandrian astronomer who proposed a geocentric system of astronomy that was undisputed for a long time
phase the particular appearance presented by the moon or a planet at a given time
vernal equinox Sun crosses the celestial equator northward
4 kinds of variable stars -binary
-cepheid variable
-mira variable
-rr lyrae
Uranus a. Discovered in 1781 by William Herschel
b. "Featureless" - pale, blue-green
c. Appears to be tipped over
d. At least 21 moons (10 discovered by Voyager Spacecraft in 1986)
The bigger the magnitude... The brighter the star
the atmosphere of venus contains large amounts of what? CO2
transmission the process in hich light passes through matter without being absorbed
Elliptical over all shaped like a flattened circle
Uranus rotates from ___ to ______. top bottom
nova a stellar explosion that results from runaway nuclear fusion in a layer of material on the surface of a white dwarf in a binary system
Mars planet with red color, named after roman god of war, has polar ice caps made of frozen water and co2, features mt. olympus, the largest volcano in the solar system and valles marineris, an extremely long and deep canyon
universe totality of all space, time, matter, and energy
Astrology The study of the positions of celestial objects in the belief that they influence human affairs.
Neptune blue appearance due to methane gas, gas planet(barely any surface), Main Moon is Triton
gamma rays shortest wave length and highest energy
Smaller planets have cooled off ____ than larger ones more
celestial pertaining to the sky or visible heaven.
What is the brightest object in the sky, after the Sun and Moon? Venus
solar eclipse occurs when the moon passes between the Earth and the sun, blocking the sunlight from reaching Earth
Galaxy a huge group of single stars, star systems, star cluster, dust, and gas bound together by gravity
Axis A straight line through the center of an object around which it rotates
moon's mass .o7x10 24th or 1.2% of the Earth
How do astronomy and astrology differ? Astronomy= Science. Astrology=Religion.
Parallax Apparent change in the position of a star in the sky
Meteorite A __________ is a meteor that has survived its fall through the atmosphere and has struck the surface of a planet or a moon
gravity an invisible force that pulls a less massive object to a more massive object
the elements more massive than iron were produced in supernova explosions
Name the three types of galaxys Spiral, Elliptical, Irregular
HR diagram a graph relating to the temperature and brightness of stars
light-year he distance that light travels in one year, about 9.5 million million kilometers
convection The transfer of heat by the movement of a liquid or gas
crater a low, bowl-shaped area on the surface of a planet or moon
diamond-ring effect During a total solar eclipse, the momentary appearance of a spot of photosphere at the edge of the moon, producing a brilliant glare set in the silvery ring of the corona. (p. 37)
angular diameter the angle that the apparent diameter of a celestial object subtends at the eye of the observer.
meteors, weather ________ fell from the sky and were thought of as _______ in ancient times, hence the name meteorology
B Even number elements like C, O, Ne etc are more common than adjacent onn
elements. This is evidence of:
A) proton capture, B) helium (alpha) capture, C) Carbon capture, D) actu-
ally there IS no clear trend like this in abundances
total eclipse a solar eclipse during which the sun is completely hidden by the moon, or a lunar eclipse during which the moon is completely immersed in the earth's umbra.
_ can also be improved by observing at shorter wave legths resolution
short-period comet a comet with an orbital period shorter than 200 years
Polaris the North Star, also known as the Home Star. The Earth spins on its axis under this . It appears to stand still in the night sky.
new moon moon phase that occurs when the Moon is between Earth and the Sun, at which point the Moon cannot be seen because its lighted half is facing the Sun and its dark side faces Earth
Medium stars dont die as fast equal mass and light
what is the minimum amount of time that can pass between a solar eclipse and a lunar eclipse? 2 weeks
Parts of the sun - outside-in Corona, Chromosphere, Photosphere, Convective layer, radiative layer, core
What was Copernicus's cosmos like? Sun-centered universe, with planets orbiting the sun, perfect circles
Define a crescent Moon Having concave and convex edges terminating in points
Occam's razor The best explanation is the one with the fewest assumptions
The simplest explanation is the most aesthetically pleasing
"KISS"---keep it simple stupid
Extrasolar planet A planet orbiting a star other than the sun. Over 400 have been found and nearly all of these were discovered by observing the Doppler shifts
ecliptic plane a flat plane defined by the Earth's orbital path
What are the two major types of optical telescopes? reflecting and refracting
cosmic microwave background radiation The remnant radiation from the big bang, which we detect using radio telescopes sensitive to microwaves(which are short-wavelength radio waves).
Trans-Neptunian Object a small, icy solar system body in an orbit around Neptune
Thanks to Pythagoras, astronomers assumed (incorrectly) that: The planets move in perfect circles.
black holes remnants of a busted star that is so dense that not even light can escape the gravity field
Chandrasekhar Limit The core of a star is kept from collapsing by the heat generated by the fusion of nuclei of lighter elements into heavier ones
irregular galaxy a galaxy with no specific form and a relatively low mass.
Law of Universal Gravitation every object in the universe attracts every other object
Distinguish Super Nova types 1. Can distinguished w/ a light curve showing how luminosity changes w/ time
2. Super Nova are MUCH more luminous
3.Type 1a complete explosion, nothing left behind
4. Spectra differ - type 1a super nova dont have hydrogen absorption lines
how far is the closest star besides the sun from us? 30 trillion miles away
Kirchhoff's Law of Spectral Analyis 1) hot glowing object emits a continuous spectrum
2) light passes through a cool gas dark lines appear in the spectrum
3) when gas is heated to a high temperature, it radiates a bright line
List all of the Planets with their Densities in order from greatest to least. EARTH 5500 kg/m^3
MERCURY5400 kg/m^3
VENUS 5300 kg/m^3
MARS 3900 kg/m^3
MOON 3300 kg/m^3
PLUTO 2000 kg/m^3
JUPITER 1300 kg/m^3
SATURN 700 kg/m^3
What is a photon?
p154 		We therefore say that light comes in individual "pieces" called PHOTONS, that have properties of both particles and waves.
What is the upper limit to the mass of a white dwarf? 1.4 solar masses
What is plate techtonics? What is it caused by? Produces? Produces horizontal movement in Earth's crust, caused by mantle convection, it produces mountian chains.
How does the process of interferometry help astronomers in viewing the universe? Computer generates very clear detail from points in the sky that would be impossible for humans to create.
Where does the remaining matter in the solar system come from 0.015% comes from satelites, comets, asteroids, meteoriods, and the interplanetary medium
each pulse we recieve from a pulsar represents one pulsation of a neutron star
How does nuclear fission differ from nuclear fusion? Nuclear fission is when nuclei are split into smaller nuclei. Nuclear fusion is when nuclei are combined or fused together to make a larger nucleus.
What does infrared dust in other galaxies tell us? -They must be a prodcut of colliding planetesimals that produced the dust because in our solar system that dust produces infrared
This telescope is designed to open new windows on our understanding of the physics of star and planet formation SIRTF or the Space Infrared Telescope Facility
Do gamma rays have a shorter or longer wavelength than visible light? Explain Gamma rays have a shorter wavelength than visible light. The reason is that gamma rays, with a frequency of 10^20 Hertz, is higher than visible light, with a frequency of ~3 x 10^16 Hertz.
E= hc/λ= hv
What is the primary reason why a Pluto flyby mission would be cheaper than a Pluto orbiter? The fuel needed for an orbiter to slow down when it reaches Pluto adds a lot of weight to the spacecraft.