The Sun
What are sunspots?
A protostar becomes a new star when what happens.
What is when nuclear reactions begin and the object reaches hydrostatic equilibrium?
The power or energy output from the surface of a star per second
What is luminosity?
A cloud of interstellar gas and dust.
What is a nebula?
Stars are assigned a spectral type, with M being the _______ stars.
What is coolest?
A small, extremely dense remnant of a star whose gravity is so immense that not even light can escape its gravitational field?
What is a black hole?
The visible surface of the Sun
What is the photosphere?
When a star with a mass similar to the Sun uses up all the helium in its core, it becomes a _______ .
What is a white dwarf?
When estimating the distance of stars from Earth, astronomers use the fact that nearby stars shift in position as observed from Earth, which is called what?
What is a parallax?
A hot, condensed object at the center of a nebula that will become a new star when nuclear reactions begin.
What is a protostar?
A group of stars that are gravitationally bound together
What is a cluster?
The combination of lightweight, atomic nuclei into heavier nuclei.
What is nuclear fusion?
Approximately 2500 km thick and has an average temperature of 15,000 K
What is the chromosphere?
What is ending up with a core too massive to be supported by pressure and come to a violent end?
Scientists can learn what about a star by studying its spectral lines?
What is composition and temperature?
A massive explosion that occurs when the outer layers of a star are blown off.
What is a supernova?
Groups of stars named after animals, mythological creatures, or everyday objects.
What are constellations?
Using the parallax technique, astronomers can accurately measure the distance of stars up to _______ away.
What is 300 parsecs?
An arc of gas ejected from the chromosphere
What is a prominence?
A star that starts with more than about 20 times the Sun's mass will what?
What is collapse forever and become a black hole?
Absolute magnitude takes distance into account when indicating the _______ of a star.
What is brightness?
The collapsed, dense core of a star that forms quickly while its outer layers are falling inward, has a radius of about 10 km, a mass 1.4 to 3 times that of the Sun, and contains mostly neutrons?
What is a neutron star?
Two stars that are gravitationally bound together and orbit a common center of mass
What are binary stars?
The Hertzsprung-Russell diagram (H-R) diagram, first plotted in the _______ , demonstrates the relationships of luminosity and temperature.
What is the twentieth century?
A wind of charged particles (ions) that flows throughout the solar system and begins as gas flowing outward from the Sun's corona at high speeds
What is solar wind?
What happens to a main-sequence star when it becomes a red giant.
What is beginning to fuse helium in its core and becoming cooler?
To estimate the distance to a nearby star, scientists _______ .
What is measure the angle of the parallax shift?
A spinning neutron star that exhibits a pulsing pattern.
What is a pulsar?
Analyzing Doppler shifts in star's spectrums
How do astronomers tell if a star is one of a binary pair?
An average star such as the Sun remains on the main sequence for this long.
What is 10 billion years?