Vocabulary
What vocabulary term describes the brightness of a star seen from Earth?
Apparent Brightness
What are the main elements found in the sun? (2)
Hydrogen and helium.
90% of stars fall along a curved band on the HR Diagram, this band is called the ______________________.
Main sequence
A low-mass star expands into this after leaving the main sequence.
Red Giant
Which are older: Population I or Population II stars?
Population II
What is a light-year?
The distance light travels in one year through empty space.
What are the three inner pieces of the sun's structure? (3)
Core, Radiative zone, Convection zone.
A star is first born when what reaction begins?
Nuclear fusion in the core.
This glowing cloud of gas forms when a low-mass star sheds its outer layers.
Planetary Nebula
What is the feature found in the corona that are red, flame-like jets of gas that rise out of the corona and travel into space.
Prominence(s)
This visual tool compares stars based on their luminosity/brightness and temperature.
H-R Diagram
What are the outer pieces of the sun's structure (3).
Photosophere, Chromosphere, Corona.
This property is one of the most important factors determining how a star will evolve.
Mass
This small, dense stellar remnant is left behind after a low-mass star dies.
White Dwarf
What are the visible features that can be seen on the sun’s external layers?
Photosphere: Granulation and Sunspots
Chromosphere: Spicules, Corona, and Prominences
What is a solar mass?
A unit of measure for mass that uses our sun as the standard.
About how long does it take for a photon made in the core of the sun to escape out the photosphere?
About 100,000 to 1,000,000 years!
Why does a high-mass star generally have a shorter lifetime than a low-mass star?
Massive stars use/fuse their nuclear fuel much faster.
True or False? If false, correct the statement.
High-mass stars never explode into supernovae because they will never run out of fuel.
False; high-mass stars run through their fuel relatively quickly and always result in a supernova explosion.
How does energy move from the sun's core to its surface?
Energy is generated in the core (as photons), does a "random walk" through the radiative zone, is carried on convection currents through the convection zone, and finally shoots out into space from the photosphere
What is a sunspot?
A relatively cool, dark region of the Sun's surface (caused by a magnetic disturbance.)
Explain what convection cells are and where they are found in the Sun.
These currents carry hot plasma outward and cool plasma back toward the core. They're found in the convective zone (between the radiative zone and the photosphere)
When on the main sequence, the brightness of a star is correlated with its...
surface temperature.
A star of about 10 solar masses is observed as very luminous and red in color. It must be a (blue giant / red giant / red supergiant / red dwarf) that is (on / off) the main sequence and it will someday become a (planetary nebula / neutron star / black dwarf).
red supergiant
on
neutron star
What fusion takes place in a red supergiant and where?
Helium fusion in a shell around the core; hydrogen fusion in a shell around that. (With a carbon core)