Astronomy 1010 Exam 1 Study Guide Flashcards

Vocabulary flashcards based on the Astronomy 1010 Exam 1 Study Guide.

Planet

Earth is one of these

Star System

A system that may have more than one star.

Star Cluster

Collections of stars found within galaxies.

Galaxy

A collection of star clusters and independent stars that orbit a common center point.

Local Group Galaxy Cluster

A group of galaxies including the Andromeda, Milky Way, and Triangulum galaxies.

Laniakea Supercluster

A relatively small part of the entire universe.

Universe

The totality of all energy and matter that exists.

Astronomical Unit (AU)

A unit of astronomical distance based on the Earth-Sun distance.

Light Year (ly)

A unit of astronomical distance based on the distance light travels in one year.

Parsec (pc)

A unit of astronomical distance approximately equal to 3.26 light-years.

Look-back Time

The phenomenon where the further away we look, the further back in time we are seeing.

Celestial Sphere

The apparent sphere of the sky on which stars appear to be located.

Celestial Poles and Celestial Equator

Earth's poles and equator projected outward onto the apparent sphere of the sky.

Ecliptic

The path of the sun across the celestial sphere over a year, representing Earth's orbit around the sun.

Constellations

Imaginary patterns of stars along the celestial sphere.

Horizon

Where the sky appears to meet the ground from your point of view.

Azimuth

The direction along the horizon (north/south/east/west) where a star is located.

Altitude

How high above the horizon (in angular units) a star is located.

Circumpolar Stars

Stars that never set from your perspective on Earth's surface.

June Solstice

The longest day of the year in the northern hemisphere (summer).

December Solstice

The shortest day of the year in the northern hemisphere (winter).

Equinoxes

Points in time when there are 12 hours of day and night everywhere on Earth.

Synchronous Rotation

The moon spins on its axis in exactly the same amount of time it takes to orbit the Earth.

Meridian

Arc from due south on the horizon, to zenith, to due north.

Right Ascension (RA)

East/west position of a star, measured in hours, minutes, and seconds.