Exam 23: Light, Astronomical Observations, and the Sun

The Sun's surface has a grainy texture produced by numerous bright markings called ________.

Galileo built the first known telescope.

The nuclear reaction process of converting hydrogen nuclei into helium nuclei is called the ________ chain.

Bright centers of solar activity are called filaments.

The study of spectroscopy was begun by ________.

Visible light emitted from the celestial bodies is only a small part of an array of energy called ________ radiation.

Sunspots appear dark because they are cooler than the surrounding solar surface.

Radio telescopes have an advantage over optical telescopes in that they can be used during daylight hours.

The most explosive events to occur on the Sun are ________.

To determine whether a celestial body is approaching or receding from Earth, astronomers employ ________.

The wavelength of red light is shorter than the wavelength of yellow light.

Streams of protons and electrons emitted from the Sun produce ________.

The source of the Sun's energy is ________.

Because lenses act like a prism to separate the colors of the spectrum, they produce a troublesome effect known as ________.

The motion of a star can be determined using the ________ effect.

Blue stars are cooler than red stars.

A hot (incandescent) gas under low pressure produces a continuous spectrum.

Astronomers currently estimate the internal temperature of the Sun at 1500˚C.

Shorter wavelengths correspond to more energetic photons.

Dark-line (absorption) spectra can be used to identify the elements present in stars.