Not occur in old star clusters
Repeat after some interval
All be visual binaries
Occur in regions of star formation
The ejected envelope of a giant star surrounding the remains of a star
A planet surrounded by a glowing shell of gas
A type of young, medium-mass star
The disk of gas and dust surrounding a young star that will soon form a star system
A spherical cloud of cometary nuclei far beyond the Kuiper Belt
The gerat nebula found just below the belt stars of Orion.
A grouping of asteroids and meteoroids between the orbits of Mars and Jupiter
The circular disk of gas around the Sun's equator from which the planets formed
A flattened belt of cometary nuclei just beyond the orbit of Neptune
They were moving faster in their orbits than the smaller planetesimals
Their stronger gravity would pull in more material
There was more material located near them that could be accreted
The smaller planetesimals were covered by a layer of material that was lost during collisions
All of the above
The core heats and the star expands
The core cools and the star contracts
The core heats and the star contracts
The core cools and the star expands
Disks are common around young stars.
Planets are round.
The sun is the least massive object in the solar system.
Disks are rare around young stars.
The planet blotting out the light of the star.
Seeing the planets next to the star.
Traveling to the star.
Varying Doppler shifts of the stars.
60 solar mass
1 solar mass
0.08 solar mass
0.001 solar mass
0.5 solar mass
Mass transfer to a white dwarf
The radiactive decay of cobalt into iron
A large nova
The collapse of the core of a massive star
Strong magnetic fields
All of these
None of these
It starts to collapse.
Its protostar life begins.
It begins to move off the main sequence.
Nuclear reactions start.
A warm starlike object that has too little mass to suppor fusion in its core.
A stage of a star's life after the white dwarf stage.
The final fate of stars like the Sun, but not less massive stars.
A stage of a star's life prior to the white dwarf stage.
The final fate of all stars.
Other names for moons of the planets
Material left over from the formation of the planets
All more massive than Earth's moon
Primarily located within 1 AU of the Sun
The result of carbon detonation
Nebulae associated with Herbig-Haro objects
Jupiter, Saturn, Uranus, and Neptune only
Everything past Mars and the asteroid belt
Jupiter, Saturn, Uranus, Neptune, and Pluto
Only Jupiter and Saturn
A contracting core of helium
Hydrogen shell burning
Expanding outer layers
All of the above
None of the above
A red giant
A white dwarf
Both of the above
None of them
Craters in old surfaces
Orbits inside the asteroids
Very few satellites
Low average density
4 times faster
16 times faster
2 times faster
1.2 times faster
0.25 times faster
A universe 1 billion years younger than ours.
Nothing - there are no galaxies one billion light-years away from us.
Much the same universe we see today.
A universe 1 billion years older than ours.
The first discovered X-ray burster
A millisecond pulsar with two planets
A leading candidate for being a black hole
A binary neutron star system
An experimental spacecraft designed to travel close to the speed of light
The star rotates too quickly
The entire star pulsates from its core to its surface
The star is too massive to be stable
The outer envelope of the star pulsates
The oldest stars in the galaxy
Main sequence stars
The time it takes a galaxy to move twice as far away from us
The speed at which galaxies are moving away from us
The size of the universe
The rate of expansion of the universe
The larger the red shift of the galaxy, the more distance it is
The greater the distance, the fainter the galaxy is in reality
The greater the distance, the more luminous the galaxy
The more distance a galaxy, the more evolved its member stars will be
About 3,000 K
About 300 K
White dwarf, neutron star
White dwarf, black hole
Pulsar, neutron star
Neutron star, black hole
Pulsar, white dwarf
General Theory of Relativity
Grand Unified Theory
Chemical composition of stars in the cluster
Total number of stars in the cluster
Luminosity of the faintest stars in the cluster
Color of the main sequence turnoff in the cluster
Dark regions at the centers of galaxies
Objects that emit very faint radio emission
Extremely luminous infrared objects
Variable X-ray sources
At least 13 billion years old.
No more than 9 billion years old.
At least 20 billion years old.
Nobody likes us
We must be at the center of the universe
The universe is expanding
The sky must be dark at night
All of the above are correct
The radius of the original neutron star before it became a black hole
The point of maximum gravity
The point at which shock waves emanate from the strong gravitational distortion the black hole creates in the fabric of spacetime
The radius at which the escape speed equals the speed of light
A supernova remnant.
A white dwarf.
A planetary nebulae.
A young massive star.
A globular cluster.
By fusion in the cores of the most massive main-sequence stars
During the formation of black holes
During the formation of planetary nebulae
Few swing their beam of synchrotron emission in our direction
Most have evolved to become black holes, which emit no light
Massive stars are very rare
Gas and dust efficiently block radio photons
Large rotation periods
Strong magnetic fields
Much mass compared to the Sun
2.5 solar mass to 10 solar mass
3.5 solar mass to 25 solar mass
1.2 solar mass to 30 solar mass
1.4 solar to 3 solar mass
Nearly vertical path
Path of constant radius
Roughly horizontal path
None of the above answers is correct