do stars and gas clouds
collide when their parent
since the distances between stars are so
large, stars do not collide with eachother.
but the gas clouds do
Describe the outcome of
both low-speed and highspeed collisions between
the shift in received frequency due to motion of a vibrating source toward or away from a
receiver. Motion toward the observer results in a blue shift (shift to shorter wavelengths). Motion
away from the observer results in a red shift (shi
Nuclear fusion of helium in stars primarily produces _. Helium fusion occurs at a _
temperature than does hydrogen fusion.
As a star becomes a red giant, its envelope _ and _.
In a typical interacting binary star system, the s
The H (Hydrogen-alpha) line has a wavelength of _ and is in the _ part of the
656 nm, red
The Sun is composed mostly of. . .
hydrogen and helium
In the classroom demonstration using the infrared camera, what material did thermal infrared
What is a neutrino
A neutrino is a very low mass particle that interacts very weakly with other matter.
What produces neutrinos in the Sun?
Neutrinos are produced by nuclear reactions in the Sun, such as the fusion of two protons to form
a deuterium nucle
how do we know that the
galaxy has a massive halo?
Although the halo of the Galaxy emits very
little light, its presence is felt from its
gravitational effects. By measuring the
speeds of stars or gas clouds in the other
part of the disk of the Galaxy, we
The system of recording very large or very small numbers by using powers of 10.
The sum and the nonluminous objects that orbit it, including the planets, comets, and asteroids.
Small, spherical, nonluminous bodies t
What occurs on the day of the equinox?
At the equinox, the Earth's axis neither points toward or away from the Sun. Day and night have
equal length of 12 hours each. The Sun rises due east and sets due west. The Sun is overhead at
noon at Earth's equator.
What is the physical
interpretation of the Hubble
It tells us that the further away a galaxy is,
the faster it is receding. This then tells us
that all galaxies are moving away from
each other. So the universe is expanding
and the distance between ga
1. How is the energy lost by radiation from the surface of a protostar replaced?
Energy radiated from the surface of a protostar is replaced by energy released through
gravitational contraction. This keeps a protostar in thermal equilibrium.
2. Why can mo