Layers of the Sun
The Visible layer of the Sun
Photosphere
This element was discovered in 1868 when Scientists were analyzing the spectrum of the Chromosphere. This element was not discovered on Earth until 1895.
Helium
Stars which are gravitationally bound to one another.
Hotter
two binary stars whose brightness varies as the two components pass in front each other.
eclipsing binaries
The outermost layer of the Sun, only visible under certain circumstances. Name comes from a word meaning crown.
Corona
The two most abundant elements in the Sun.
Hydrogen and Helium.
The amount of energy emitted by a star.
Luminosity / absolute magnitude
Main sequence
Scientists in the early 1800's noticed that the Sun produced this type of spectrum. It looked like a continuous spectrum, but had dark bands.
Absorption spectrum
Innermost region of the Sun, where temperatures may reach 15 million K.
Core
The atoms in the core of the Sun are ionized, meaning that are stripped of one or more of their electrons. What is this ionized gas called?
Plasma
How bright a star appears to us on Earth
Apparent Magnitude
On an H-R diagram, what variable is plotted on the x / horizontal axis.
Temperature
The category of star on an H-R diagram which is cool and dim
Main sequence
DAILY DOUBLE: In this layer of the Sun, energy is transported as hot plasma rises and cooler plasma sinks.
Convection zone
This type of spectrum appears as only a few bright lines. A gas of an element would show this type of spectrum.
Emission Spectrum
There are seven spectral classes which Scientists may sort Stars into according to their temperature. What is the hottest class in this system?
Class O stars
On an H-R diagram, what variable is on the y / vertical axis?
Luminosity
White dwarf
This layer of the Sun was previously only visible during an eclipse. In the 17th century, observers described it as a narrow red streak, thus giving it a name meaning "colored streak".
Chromosphere
A reaction where atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.
nuclear fusion
The absolute magnitude of a star can be determined from these two factors.
Apparent magnitude and distance
What category of star on the H-R diagram has a low surface temperature, but a high luminosity.
Giants
What percentage of the Sun is composed of hydrogen (by mass)? (I will accept it if it is within 2%).
73 percent