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ASTR 205 FINAL EXAM QUESTIONS AND
ANSWERS 2025
Field of View - ...ANSWER... ✔ ✔The region you can
see in an image
solar system - ...ANSWER... ✔ ✔The sun, and its
planets, asteroids, comets, and so on
planet - ...ANSWER... ✔ ✔A small, nonluminous body
that shines by reflected light
star - ...ANSWER... ✔ ✔A globe of gas held
together by its own gravity and supported by the
internal pressure of its hot gases, which generate energy
by nuclear fusion
astronomical unit (AU) - ...ANSWER... ✔ ✔The
average distance from Earth to the sun; 1.5 × 108
kilometers (km)
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light-year (ly) - ...ANSWER... ✔ ✔A unit of distance;
the distance light travels in one year, roughly 1013
kilometers (km) or 63,000 AU
galaxy - ...ANSWER... ✔ ✔A large system of stars,
star clusters, gas, dust, and nebulae orbiting a common
center of mass
universe - ...ANSWER... ✔ ✔The entire celestial
cosmos, including planets, stars, galaxies, the contents of
intergalactic space, and all matter and energy
Milky Way Galaxy - ...ANSWER... ✔ ✔The spiral
galaxy containing our sun; it is visible in the night sky as
the Milky Way
spiral arm - ...ANSWER... ✔ ✔A long spiral pattern
of bright stars, star clusters, gas, and dust. Such arms
extend from the center to the edge of the disk of spiral
galaxies.
constellation - ...ANSWER... ✔ ✔One of the stellar
patterns identified by name, usually of mythological
gods, people, animals, or objects. Also, the region of the
sky containing that star pattern
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asterism - ...ANSWER... ✔ ✔A named grouping of
stars that is not one of the recognized constellations
magnitude scale - ...ANSWER... ✔ ✔The astronomical
brightness scale. The larger the number, the fainter the
star
apparent visual magnitude - ...ANSWER... ✔ ✔The
brightness of a star as seen by human eyes on Earth
flux - ...ANSWER... ✔ ✔The amount of light energy
that hits one square meter per second, a rigorous
definition of brightness. The magnitude of a star is
related mathematically to the flux of light received on
Earth from the star, in other words, the star's brightness
celestial sphere - ...ANSWER... ✔ ✔An imaginary
sphere of very large radius surrounding Earth and to
which the planets, stars, sun, and moon seem to be
attached
horizon - ...ANSWER... ✔ ✔The circular boundary
between the sky and Earth
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zenith - ...ANSWER... ✔ ✔The point on the celestial
sphere directly above the observer. The opposite of the
nadir
nadir - ...ANSWER... ✔ ✔The point on the celestial
sphere directly below the observer. The opposite of the
zenith
north celestial pole - ...ANSWER... ✔ ✔The point on
the celestial sphere directly above Earth's North Pole
south celestial pole - ...ANSWER... ✔ ✔The point on
the celestial sphere directly above Earth's South Pole
celestial equator - ...ANSWER... ✔ ✔The imaginary
line around the sky directly above Earth's equator. This
line divides the sky into two hemispheres
- angular distance
- arc minute
- arc second - ...ANSWER... ✔ ✔- The angle formed
by lines extending from the observer to two locations
ASTR 205 FINAL EXAM QUESTIONS AND
ANSWERS 2025
Field of View - ...ANSWER... ✔ ✔The region you can
see in an image
solar system - ...ANSWER... ✔ ✔The sun, and its
planets, asteroids, comets, and so on
planet - ...ANSWER... ✔ ✔A small, nonluminous body
that shines by reflected light
star - ...ANSWER... ✔ ✔A globe of gas held
together by its own gravity and supported by the
internal pressure of its hot gases, which generate energy
by nuclear fusion
astronomical unit (AU) - ...ANSWER... ✔ ✔The
average distance from Earth to the sun; 1.5 × 108
kilometers (km)
,2|Page
light-year (ly) - ...ANSWER... ✔ ✔A unit of distance;
the distance light travels in one year, roughly 1013
kilometers (km) or 63,000 AU
galaxy - ...ANSWER... ✔ ✔A large system of stars,
star clusters, gas, dust, and nebulae orbiting a common
center of mass
universe - ...ANSWER... ✔ ✔The entire celestial
cosmos, including planets, stars, galaxies, the contents of
intergalactic space, and all matter and energy
Milky Way Galaxy - ...ANSWER... ✔ ✔The spiral
galaxy containing our sun; it is visible in the night sky as
the Milky Way
spiral arm - ...ANSWER... ✔ ✔A long spiral pattern
of bright stars, star clusters, gas, and dust. Such arms
extend from the center to the edge of the disk of spiral
galaxies.
constellation - ...ANSWER... ✔ ✔One of the stellar
patterns identified by name, usually of mythological
gods, people, animals, or objects. Also, the region of the
sky containing that star pattern
,3|Page
asterism - ...ANSWER... ✔ ✔A named grouping of
stars that is not one of the recognized constellations
magnitude scale - ...ANSWER... ✔ ✔The astronomical
brightness scale. The larger the number, the fainter the
star
apparent visual magnitude - ...ANSWER... ✔ ✔The
brightness of a star as seen by human eyes on Earth
flux - ...ANSWER... ✔ ✔The amount of light energy
that hits one square meter per second, a rigorous
definition of brightness. The magnitude of a star is
related mathematically to the flux of light received on
Earth from the star, in other words, the star's brightness
celestial sphere - ...ANSWER... ✔ ✔An imaginary
sphere of very large radius surrounding Earth and to
which the planets, stars, sun, and moon seem to be
attached
horizon - ...ANSWER... ✔ ✔The circular boundary
between the sky and Earth
, 4|Page
zenith - ...ANSWER... ✔ ✔The point on the celestial
sphere directly above the observer. The opposite of the
nadir
nadir - ...ANSWER... ✔ ✔The point on the celestial
sphere directly below the observer. The opposite of the
zenith
north celestial pole - ...ANSWER... ✔ ✔The point on
the celestial sphere directly above Earth's North Pole
south celestial pole - ...ANSWER... ✔ ✔The point on
the celestial sphere directly above Earth's South Pole
celestial equator - ...ANSWER... ✔ ✔The imaginary
line around the sky directly above Earth's equator. This
line divides the sky into two hemispheres
- angular distance
- arc minute
- arc second - ...ANSWER... ✔ ✔- The angle formed
by lines extending from the observer to two locations
