Astronomy Terms 4 Flashcards

Terms Definitions
Vernal Equinox
Extrusive Igneous Rock
sulfuric acid clouds.
one complete REVOLUTION=
one year
Chemical Composition:
CO2 - 95.3%
Nitrogen - 3.5%
Refracting Telescope
bending lightlarge lens
light can bounce off matter
planet factoids; smallest terrestrial planet, biggest temperature variations of an object in the solar system.
Last of the inner planets
large space orbiting a star
a quantum of electromagnetic radiation, usually considered as an elementary particle that is its own antiparticle and that has zero rest mass and charge and a spin of one.
Oort Cloud
(astronomy) a hypothetical huge collection of comets orbiting the sun far beyond the orbit of Pluto, A spherical region of comets that surrounds the solar system out to more than 1,000 times the distance from the sun
large star fusing heavier elements where pressure > gravity
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They are darker because they are cooler regions on the Sun.
Scientific Model
"Carefully devised mental conception of how something works, framework that helps scientists think about some aspect of nature. Abstract, mathematical, or mechanical. Not necessary truth. Based on assumptions"
falling masses accelerate--> change in velocity
-accelerations are only possible whent hings are acted upon
the hottest color of a star
early building blocks of planets ,which collided and grew larger by sticking together,eventually combining to form planets
Which planet reaches opposition more frequently?
an electromagnetic wave of extremely high frequency, 1 GH3 or more, and having wavelengths of from 1 mm to 30 cm.
any celestial body orbiting around a planet or star
What is the most important parameter that determines the behavior of a star?
tides forces
pull of gravity and its effects
protoplanetary disks
disk of material encircling a protostar or a newborn start
introduced the idea of ellipses for orbits instead of perfect circles
Grouping of stars in the night sky
Postulated that light consists of particles?
Isac Newton
the study of the sun,moon, planets, stars, and other objects in the sky
What happens to the gravitational force between two objects if the distance between them is doubled?
It's quartered.
polar icecap- frozen water and carbon dioxide
outer planets
Jupiter, Saturn, Uranus and Neptune. Much larger than the inner planets and made of gas.
a system of organizing time that defines the beginning, length, and divisions of a year
solar wind
a stream of electrically charged particles sent out by the corona
earth period of revolution
365 and 1/4 days
perhilionhelium flash
the runaway explosive burning of helium in the degenerate helium core of a red giaant
Electroweak epoch
weak and electromagnetic forces act as one
a plane that defines what's visible on the celestial sphere
solar system
The sun and the nonluminous objects that orbit it, including the plants, comets, and asteroids
Who made one of the first calculations of the earth's circumference?
mercury is 180 degrees completely from earth (cannot see mercury because it is behind the sun)
superior conjunction
Currently, the size of our universe is _______________
the period of time taken by a particular planet (e.g. Mars) to make a complete rotation on its axis
caused by Earth's axis tilting to or from Sun
Spectral Analysis
the identification of chemicals by the appearance of their spectra, the analysis of celestial bodies by interpreting the variation in color values from imagery uses visible light, can determine chemical composition and motion.
a contracting cloud of gas and dust with enough mass to form a star
greatest elongation
the largest possible angle between the sun and an interior planet
condensation theory
describes the origin of the solar system
Magnetic Cycle
Lasts 22 years, linked to the differential rotation of the Sun causing the polarity of the Sun's magnetic field to flip every 11 years, connected to Sun spot cycle.
Big bang theory
states that a tremendous explosion occurred in space sending matter in all directions
dark matter
matter that does not give off electromagnetic radiation but is quite abundant in the universe
The stars of different surface temperatures and spectral types that burn hydrogen in their cores are known as
Main Sequence stars
What aspect of an object can be determined by noting in an emission or absoprtion spectrum which spectral lines are present and which are absent?
(of a heavenly body) convex at both edges, as the moon when more than half full.
How are craters formed?
A meteoroid strikes the Moon, releasing huge amounts of energy; the resulting explosion ejects material, leaving behind a crater.
The life cycle of a star can be determined by its size.
eclipsing binary
a star system in whichh one star periodically blocks the light from another
continuous spectrum
One of Kirchhoff's Laws states that a hot solid, liquid, or gas, (dense) under high pressure, gives off a ________________ spectrum.
Elliptical Galaxy
a galaxy shaped like a flattened ball, containing only old stars
solar eclipse
the blocking of sunlight to earth that occurs when the moon is directly between the sun and earth
the faint glow of light left over from the big bang
Orion Nebula
Giant cloud in which stars and planets are forming, 1500 light years away
gas giant
the jovian planets made of frozen gas and much larger than terrestrial planets
Stefan-Boltzmann Law
the law stating that the amount of electromagnetic energy emitted from the surface of a body, summed over the energies of all photons of all wavelengths emitted, is proportional to the fourth power of the temperature of the body
radius of the Galactic Bulge of the Galaxy
6000 ly
What is a moon?
An object that orbits a planet
north celestial pole
point on the celestial sphere directly above the Earth's north pole
A small ball of ice that can have a coma and a tail if close to the sun.
What did Kelper discover?
the geometry of ellipses to explain the planets,comets and moons orbital path
Hydrostatic Equalibrium determines
size of the star (not mass, just density and volume)
A contracting interstellar cloud ______
fragments repeatedly to form hundreds of separate stars.
a large cloud of gas and dust in the space between stars. Region where sars are born. 70% hydrogen.
compared to the star it evolved from, a white dwarf is
hotter and dimmer
the 5th planet from the sun; it is a gas giant; largest planet in the solar system; it has rings and dozens of moons. It has a huge storm that has lated for about 400 years. This storm is like a hurricane and its name is The Great Red Spot
to let down, as hair, or wear or let hang in loose disorder, as clothing.
North & South Celestial Poles
points in the sky directly above earth's north and south poles
what pattern is helpful to discriminate a meteorit from a meteor wrong
cut, polished, and dipped in acid
Can we see the entire universe?
no. probably only a tiny portion.
meteor shower
A period of time when you can see a large number of meteors in a short period of time, in some _____ thousands per hour. Some ____ are periodic, occurring at about the same time every year.
Eirs, Pluto, Ceres
3 of the 5 dwarf planets of the Solar System
what is perigee and apogee?
The closest point to the earth is perigee and the farthest is apogee.
1st Quarter Phase
you can see half of the sunlit side of the moon
During the main sequence of its life, a star fuses...
hydrogen and helium in its core
The Sun's radiation pressure is the cause
the dust tail pointing generally
away from the Sun and flaring out
What is the difference between a reflecting and a refracting telescope?
A reflecting telescope uses a mirror to focus light; a refracting telescope uses a lens.
An X-ray binary contains at least one stellar component that is
a compact stellar remnant that is accreting material from an evolving star just leaving the main sequence
The heaviest nuclei of all are formed
E. in a type II core collapse supernova event
The heaviest nuclei of all are formed
A. in the horizontal branch
B. in dense white dwarfs
C. during nova explosions
D. in the ejection of matter in the planetary nebula
E. in a type II core collapse supernova event
What is the Law of Hydrostactic Equillibrium?
the weight pressing down on a layer of gas in a star must be balanced by the pressure in the gas.
What would happen if more mass was added to a 1.4 solar mass neutron star?
E. It would blow off mass as an X-ray burster
What would happen if more mass was added to a 1.4 solar mass neutron star?
A. It would erupt as a Type I supernova
B. It would eventually become a black hole, via a hypernova explosion
C. It would grow larger, temporarily becoming a red giant again
D. All of its protons and electrons would turn into neutrons
E. It would blow off mass as an X-ray burster
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