36 terms

Earth Sci: Chapter 20 - Telescopes and Stargazing Combined Set

optical telescope
a telescope that uses lenses or mirrors to collect and focus visible light
radio telescope
A telescope used to detect radio waves from objects in space
A device that uses a prism or diffraction grating to separate light into its color components.
visible spectrum
tiny part of electromagnetic spectrum to which our eyes are sensitive
continuous spectrum
A spectrum of light in which there are no gaps, so that each region blends directly into the next
bright line spectrum
called an emission spectrum; light of only certain wavelengths is present
dark line spectrum
called an absorption spectrum; blackened areas of a continuous spectrum represent missing wavelengths that have been absorbed by a filter or gas cloud.
charge coupled device
a dime sized component of a camera into which light enters and is converted into an electronic signal
doppler effect
A change in frequency of sound or electromagnetic waves caused by motion of the source, observer, or both.
red shift
an increase of the wavelength of radiation caused by bodies moving apart from one another (wavelength appears longer)
blue shift
A decrease in the wavelength of radiation emitted by an approaching celestial body (wavelength appears shorter)
Process that links separate telescopes so they act as one telescope, producing more detailed images as the distance between them increases.
multiple mirror telescope
telescope with more than one mirror
reflecting telescope
A telescope invented by Issac Newton that uses mirrors to produce a view for the viwer and that eliminates the chromatic aberration that is seen in refracting telescopes
refracting telescope
A telescope used by Galileo that uses a convex lenses to gather and focus light
Schmidt-Cassegrain telescope
a telescope that combines a reflector's optical path with a optical corrector plate to make a compact astronomical instrument that uses simple spherical surfaces
alignmnet of two celestial bodies such that they present the least angular separation (6 degrees or less when veiwed from Earth)
A group of stars that form a pattern in the sky
A region of the sky that contains a recognizable star pattern and that is used to describe the location of objects in space
A group of stars that form a pattern in the sky
apparent path of the Sun and planets across the sky
a point where the dome of the sky meets the Earth
the angular separation between two bodies
when a celestial body is opposite from the Sun in the sky
Universal Time (UTC)
solar time along the prime meridian passing through Greenwich England (zulu time).
local time
time based on the rotation of the earth as compared to the sun
DST = UTC - 4 hours
EST = UTC - 5 hours
the angular distance to a point on a celestial object measured north or south from the equator
right ascension
a measure of how far east a celestial object is from the point at which the sun appears on the first day of spring
celestial equator
The projection of the earth's equator into space (on the celestial sphere); position of 0 degrees declination
The study of the moon, stars and other objects in space
diffuse nebula
a nebula containing gas and dust, but containing no star at its center
double star
Two stars that appear close together in the sky. If the two stars revolve around each other, the system is called a binary.
a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.
globular star cluster
a spherical collection of stars that orbits a galactic core as a satellite
light year
a unit of astronomical distance equivalent to the distance that light travels in one year, which is 9.5 × 10¹² km (nearly 6 trillion miles)
open star cluster
a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age
planetary nebula
a kind of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from old red giant stars late in their lives
variable star
a star whose brightness as seen from Earth fluctuates

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