Astronomy Exam Review

Flashcards for Astronomy Exam Review

Galaxy

Made of hundreds of billions of Stars with interstellar matter (Gas Dust).

Lunar Eclipse

Can only happen during a Full Moon when the Earth is between the Sun and Moon

Constellation

A region of the sky and all objects in that region

Asterism

Name given to a traditional star pattern where there is danger of confusion.

Rotation

An object spinning on its axis.

Revolution

When an objects orbits a second object

North Star

The star that the axis of the North Pole points toward.

Ecliptic

The path that the Sun takes through the sky.

Winter Solstice

The first day of winter

Summer Solstice

The first day of summer.

Vernal Equinox

The first day of spring

Autumnal Equinox

The first day of fall

Precession

A slow circular motion of the Earth’s axis of rotation.

Sidereal Month

27.3 days, time needed to complete one orbit of the earth

Synodic Month

29.5 days, time needed to go through all of the phases

Blood Moon

Earth is between the sun and the moon (Earth’s shadow falls on the moon). Moon is reddish in color. Only happens during a full moon.

Blue Moon

If there are four full moons instead of three in a season, the third one is called “Blue moon”

Newton

Invented a new telescope using mirrors, known as the first reflector telescope. Proposed Newton's Laws of Motion and Introduced gravitational attraction.

Galileo

Invented the telescope. Discovered four large moons orbiting Jupiter, supporting Kepler's laws, published his astronomical observations.

Ptolomy

Proposed an Earth-centered view of the universe (Geocentric model) and introduced the concept of epicycles to explain retrograde motion of planets.

Kepler

Developed 3 Laws of Planetary Motion: orbit of a planet is an ellipse, planets sweep out equal areas in equal times, and the square of a planet's orbital period is proportional to the cube of the semi-major axis.

Copernicus

Proposed a Sun-centered universe (Heliocentric model) with planets in circular orbits.

Brahe

Observed that the Earth rotates daily and collected precise data on planetary positions.

Maxwell

Unified electromagnetic theory; wavelengths define the nature of radiation.

Young

Demonstrated the wave nature of light (behaved like water waves).

Einstein

Introduced the equation E=mc² to describe the equivalence of mass and energy, light is composed of particles called photons, and developed the theory of relativity.

Mercury

A terrestrial planet that is rocky, has an iron core, is relatively warm and close to the sun, has few moons, no rings, the smallest planet, closest to the Sun, and has extreme temperature variations.

Venus

A terrestrial planet that is rocky, has an iron core, is relatively warm and close to the sun, has few moons, no rings, is similar in size to Earth, has a thick, toxic atmosphere, and is the hottest planet.

Earth

A terrestrial planet that is rocky, has an iron core, is relatively warm and close to the sun, has few moons, no rings, is our home, the only planet known to support life, and has liquid water on its surface.

Mars

A terrestrial planet that is rocky, has an iron core, is relatively warm and close to the sun, has few moons, no rings, is known as the Red Planet, has giant volcanoes and dry riverbeds, and may have once had liquid water.

Jupiter

A jovian planet that is gaseous, cold, far from the sun, has lots of moons, a ring system, is less dense. It is the largest planet, with a prominent Great Red Spot storm, and numerous moons.

Saturn

A jovian planet that is gaseous, cold, far from the sun, has lots of moons, a ring system, is less dense. It is famous for its stunning ring system, and is the second-largest planet.

Uranus

A jovian planet that is gaseous, cold, far from the sun, has lots of moons, a ring system, is less dense. Rotates on its side, has a pale blue color due to methane, and is an ice giant.

Neptune

A jovian planet that is gaseous, cold, far from the sun, has lots of moons, a ring system, is less dense. A deep blue color, with strong winds, and is the farthest planet from the Sun.

Pluto

A dwarf planet located in the Kuiper Belt that is smaller than Earth's moon and has a thin atmosphere primarily composed of nitrogen, methane, and carbon monoxide.

Moon

Earth's only natural satellite that is tidally locked with Earth, heavily cratered due to impacts from space objects, and is responsible for tides on Earth.

Meteor

Smaller space rocks that exist in space.

Meteorite

Meteoroids that survive atmospheric entry and land on Earth, exist in the atmosphere of the Earth.

Meteoroid

Smaller space rocks, exist in space.

Comet

Small, icy solar system body that orbits the sun, often developing a bright, fuzzy coma and a long tail when it approaches the sun.

Asteroid

Rocky objects orbiting the sun.

Oort Cloud

A spherical cloud of icy objects.

Kuiper Belt

A region of the solar system, which contains many comets and asteroids.

Plages

Bright hotter spots on the surface of the sun.

Filaments

Dark streaks in the corona that loop to produce prominences.

Prominences

Filaments loop to produce prominences.

Coronal Holes

Act as conduits for gases to flow out of the sun.

Solar Flares

Release high energy particles and X-ray and UV radiation from the sun; are violent releases of energy.

Coronal Mass Ejections

Huge balloon-shaped volumes released from the corona that release 2 trillion tons of matter per ejection at 400 km/s.

Photosphere

Visible light emitting region of the sun; the sphere of light.

Chromosphere

Sphere of color above the photosphere.

Corona

The sun's uppermost layer; hot outer layer of the sun’s atmosphere.

Heliosphere

Bubble in space containing the sun and planets, created by the solar wind.

White Dwarf

The remnant remaining at the end of a small mass star.

Planetary Nebula

Ejected material (a ring) around a contracting red giant star.

Red Giant

A huge cool star that forms as a result of helium burning for a small mass star.

Supernova

An exploded intermediate mass star that gives off an enormous amount of energy.

Neutron Star

What is left after a supernova explosion; a teaspoon of neutron star has the mass of an aircraft carrier.

Pulsar

A spinning neutron star that sends out jets of radiation.

Black Hole

Completely collapsed huge star at the centers of all galaxies from which nothing can escape, not even light.

Singularity

The point in space where a black hole is located; has a mass of a billion stars with no volume.

Event Horizon

Imaginary border of a black hole.

Apparent Magnitude

The apparent brightness of objects in the sky from Earth.

Absolute Magnitude

Brightness of an object if a standard luminosity distance of 10.0 parsecs.

Binary Star

Two stars that are in orbit around their center of mass.

Center of Mass

The position of the average point of mass of a binary star system; will be closer to the larger mass star.

Inverse Square Law

As distance doubles the luminosity of light changes by a factor of l=1/d².

Earth-Moon-Sun system at summer solstice in the northern hemisphere

Earth's tilt is most pronounced, North Pole tilted directly toward the sun.

Earth-Moon-Sun system at winter solstice in the northern hemisphere

Earth's axis is tilted furthest away from the sun.

Lunar Eclipses

Earth is between sun and moon.

Solar Eclipses

Moon is between sun and earth.

Polaris Finding Method

By using the pointer stars of the Big Dipper, you can locate Polaris.

Leo Finding Method

By looking for its bright blue - white star regulus, you can locate Leo.

Arcturus Finding Method

Follow the arc of the handle of the Big Dipper and “Arc to Arcturus”

First Quarter

One of the Moon Phases.

Waxing crescent

One of the Moon Phases.

New

One of the Moon Phases.

Waning crescent

One of the Moon Phases.

Third Quarter

One of the Moon Phases.

Waning Gibbous

One of the Moon Phases.

Full

One of the Moon Phases.

Waxing Gibbous

One of the Moon Phases.

Terrestrial vs. Jovian Planets

Terrestrial = earth like; Jovian = Jupiter like

Planet order

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

Comet Parts

Coma, Nucleus, Tail

Perseids

Major meteor shower in August.

Leonids

Major meteor shower in November.

Death of a small mass star

Runs out of Hydrogen, Shrinks, Temperature increases, Helium begins to fuse, planetary nebula forms, white dwarf forms, white dwarf cools to a brown dwarf.

Death of an intermediate mass star.

Runs out of Hydrogen, Shrinks, Temperature increases, Helium begins to fuse, Shells of Carbon, Neon, Oxygen, Silicon form as temperatures continue to increase, Iron core forms, rebounds exlposion, neutron star.

Death of a large mass star.

Runs out of Hydrogen, Shrinks, Temperature increases, Helium begins to fuse, Star becomes a singularity.

Hertzsprung-Russell Diagram

a. Relationship between temperature and color: The more red, the colder, the more blue, the hotter. b. Relationship between mass and luminosity: The more luminous, the more massive it is. c. Relationship between mass and color: For main sequence stars, the larger the mass, the bluer the color