Stars

Front 1

Doppler Effect

Back 1

A change in the observed frequency of a wave, as of sound or light, occurring when the source and observer are in motion relative to each other, with the frequency increasing when the source and observer approach each other and decreasing when they move apart. The motion of the source causes a real shift in frequency of the wave, while the motion of the observer produces only an apparent shift in frequency. Also called Doppler shift.

Front 2

Photosphere

Back 2

The visible outer layer of a star, especially of the sun.

Front 3

Chromosphere

Back 3

An incandescent, transparent layer of gas, primarily hydrogen, several thousand miles in depth, lying above and surrounding the photosphere of a star, such as the sun, but distinctly separate from the corona.

Front 4

Corona

Back 4

A faintly colored luminous ring appearing to surround a celestial body visible through a haze or thin cloud, especially such a ring around the moon or sun, caused by diffraction of light from suspended matter in the intervening medium. Also called aureole.

Front 5

Solar Winds

Back 5

A stream of high-speed, ionized particles ejected primarily from the sun's corona.

Front 6

Sunspot

Back 6

Any of the relatively cool dark spots appearing periodically in groups on the surface of the sun that are associated with strong magnetic fields.

Front 7

Prominence

Back 7

A tonguelike cloud of flaming gas rising from the sun's surface, visible as part of the corona during a total solar eclipse.

Front 8

Solar Flare

Back 8

A sudden eruption of magnetic energy released on or near the surface of the sun, usually associated with sunspots and accompanied by bursts of electromagnetic radiation and particles. Ultraviolet and x-ray radiation from solar flares often induce electromagnetic disturbances in the earth's atmosphere.

Front 9

Aurora

Back 9

An atmospheric phenomenon consisting of bands, curtains, or streamers of light, usually green, red, or yellow, that move across the sky in polar regions. It is caused by collisions between air molecules and charged particles from the sun that are trapped in the earth's magnetic field

Front 10

Nuclear Fusion

Back 10

A reaction in which two nuclei combine to form a nucleus with the release of energy Sometimes shortened to fusion

Front 11

Spectroscopy

Back 11

Study of spectra, especially experimental observation of optical spectra.

Front 12

Spectrum

Back 12

The distribution of a characteristic of a physical system or phenomenon

Front 13

Electromagnetic radiation

Back 13

Radiation consisting of self-sustaining oscillating electric and magnetic fields at right angles to each other and to the direction of propagation. It does not require a supporting medium and travels through empty space at the speed of light