Studying Sun

• Arrangement of electromagnetic radiation according to wavelength.

  Electromagnetic spectrum
• Electromagnetic radiation includes gamma rays, X-rays, ultraviolet light, visible light, infrared radiation, microwaves, and radio waves.
• Small packet of light energy.

  Photon
• Distance from one wave crest to the next.

  Wavelength
• Study of the properties of light that depend on wavelength.

  Spectroscopy
• Uninterrupted band of light emitted by an incandescent solid, liquid, or gas under pressure.

  Continuous spectrum
• Continuous spectrum produced when white light passes through a cool gas under low pressure.

  Absorption spectrum
• Series of bright lines of particular wavelengths produced by a hot gas under low pressure.

  Emission spectrum
• Apparent change in frequency of electromagnetic or sound waves caused by the relative motions of the source and the observer.

  Doppler effect
• Telescope that uses a lens to bend or refract light.

  Refracting telescope
• Important lens in a refracting telescope, the objective lens, produces an image by bending light from a distant object so that the light converges at an area

  Focus
• Property of a lens whereby light of different colors is focused at different places.

  Chromatic aberration
• Telescope that reflects light off a concave mirror, focusing the image in front of the mirror.

  Reflecting telescope
• Properties of Optical Telescopes

  Light-gathering power

  Resolving power

  Magnifying power
• Telescope designed to make observations in radio wavelengths.

  Radio telescope
• A radio telescope focuses the incoming radio waves on an antenna
• Advantages of Radio Telescopes

  • Radio telescopes are much less affected by turbulence in the atmosphere, clouds, and the weather.

  • No protective dome is required, which reduces the cost of construction.

  • Radio telescopes can “see” through interstellar dust clouds that obscure visible wavelengths.
• Advantages of Reflecting Telescopes

  • Most large optical telescopes are reflectors. Light does not pass through a mirror, so the glass for a reflecting telescope does not have to be of optical quality.
• Orbit above Earth’s atmosphere and thus produce clearer images than Earth-based telescopes.

  Space telescopes
• The first space telescope, built by NASA

  Hubble Space Telescope.
• To study X-rays, NASA uses the:

  Chandra X-Ray Observatory
• Used to study both visible light and gamma rays.

  Compton Gamma-Ray Observatory
• Study infrared radiation.

  James Webb Space Telescope
• Region of the sun that radiates energy to space, or the visible surface of the sun.

  Photosphere
• It exhibits a grainy texture made up of many small, bright markings produced by convection.

  Granules
• First layer of the solar atmosphere found directly above the photosphere.

  Chromosphere
• Outer, weak layer of the solar atmosphere.

  corona
• Stream of protons and electrons ejected at high speed from the solar corona.

  Solar wind
• Dark spot on the sun that is cool in contrast to the surrounding photosphere.

  Sunspot
• Huge cloudlike structures consisting of chromospheric gases.

  Prominences a
• Outbursts that normally last about an hour and appear as a sudden

  brightening of the region above a sunspot cluster.

  Solar flares
• Result of solar flares, are bright displays of ever-changing light caused by solar radiation interacting with the upper atmosphere in the region of the poles.

  Auroras
• Way that the sun produces energy.

  Nuclear fusion
• As the sun is already 4.5 billion years old, it is “middle-aged.”