Astronomy Exam 2

an electric and magnetic disturbance that transports energy at the speed of light c

the distance between the peaks of a wave

Nanometers are a unit of measurement equal to one billionth of a meter, used to measure wavelengths of light

the number of waves that pass a stationary point in 1 second

packet of light waves that can act as a particle or as a wave. The energy carried by a photon is proportional to its frequency and inversely proportional to its wavelength.

display of light that is viewed or recorded after being sorted in order of wavelength or frequency

gamma-rays, X-rays, ultraviolet (UV) radiation at the higher frequencies, and infrared (IR) radiation, microwaves, and radio waves at the lower frequencies

specific wavelength ranges in the electromagnetic spectrum where Earth's atmosphere allows certain types of radiation, like visible light and radio waves, to pass through with minimal absorption.

Use a primary lens to bend and focus light onto an image

Easier to build than refracting/ use a primary mirror to focus the light. Is not affected by chromatic aberration

Magnifies the image produced by the telescope’s primary lens or mirror

The distance between the lens and the image sensor when the subject is in focus.

causes refracting telescopes to not bring all colors to the same focus, resulting in color fringes around the images

corrects for chromatic aberration

reflecting telescopes:

use lenses or mirrors to gather and focus light from distant objects

reflecting telescopes:

are astronomical instruments that detect radio waves from space.

The telescopes ability to collect light, most important feature

the ability of a telescope to reveal fine detail and is expressed by the equation

caused by the interaction of light waves with the telescope’s apertures, limit the amount of detail that can be seen

the ability of a telescope to make an object look bigger, least important

The air on top of a mountain is relatively steady, and the seeing is better

Observatories are located far from cities to avoid light pollution

light first comes to a focus at the prime focus, but a secondary mirror can direct light to other locations such as the Cassegrain focus. The Newtonian focus and Schmidt-Cassegrain focus are other focus locations used in some smaller telescopes

Because Earth rotates, telescopes must have this to stay pointed at celestial objects

using prisms or a grating spread light out according to wavelength to form a spectrum, revealing hundreds of spectral lines produced by atoms and molecules in the object being studied

contains lines of known wavelengths allows astronomers to measure the precise wavelengths of individual spectral lines produced by an astronomical object

are not electromagnetic radiation; they are subatomic particles such as electrons and protons traveling at nearly the speed of light, arriving from mostly unknown cosmic sources

Contains a nucleus surrounded by a cloud of electrons

made up of one or more positively charged protons and, except for hydrogen, uncharged neutrons

Atoms of the same element (that is, having the same number of protons) with different numbers of neutrons

an atom that has lost or gained an electron through ionization

The force that allows electrons in an atom are attracted to the nucleus

an electron is raised to a higher orbit by a collision between atoms or the absorption of a photon having the proper energy

The sum of the agitation of the particles in an object, heat is the flow

Collisions among the particles in a hot, dense object accelerate electrons and cause the emission of this

states that the hotter an object, the more total energy the blackbody radiates

quantifies the relationship between a blackbody’s temperature and the wavelength of maximum intensity

a hot solid, liquid, or dense gas emits electromagnetic radiation at all wavelengths and produces a continuous spectrum

an excited, low-density gas produces an emission spectrum containing emission lines

a light source viewed through a low-density, cool gas produces an absorption spectrum containing absorption lines

The change in wavelength of radiation- red receding, blue moving towards

Spectral lines in the visible and near-ultraviolet spectrum of hydrogen produced by transitions whose lowest orbit is the second.

the part of its velocity directed toward or away from Earth, what the doppler effect reveals

The fine structure visible on the solar surface caused by rising currents of hot gas and sinking currents of cool gas below the surface.

The study of the interior of the Sun by the analysis of its modes of vibration.

The widely distributed, low-level magnetic field extending up through the Sun’s visible surface

A graph showing the latitude of sunspots versus time; first plotted by W. W. Maunder in 1904.

A measure of the energy output of the Sun; the total solar energy striking 1 m2 just above Earth’s atmosphere in 1 second.

A series of three nuclear reactions that build a helium atom by adding together protons; the main energy source in the Sun.

A neutral, massless atomic particle that travels at or nearly at the speed of light.

the innermost layer of the Sun's atmosphere, emitting visible light. It is the region where energy is transferred from the Sun's core to the outer atmosphere