True or False: The Sun makes up approximately 75% of the mass in our solar system
False -- more than 99%
_____________________ refers to the actual brightness of the star, measured in Watts. It is an intrinsic property of the star based on its size
Luminosity
Stars are born in ______________ _____________, which are special types of absorption nebulae with temperatures cool enough for molecules to form
BONUS: These types of clouds contain large amounts of _____________, which is why they block light
Molecular clouds
BONUS: Dust
When first leaving the main sequence, both low mass and high mass stars will become ___________ ________________
Red giants/supergiants
If gamma rays are produced in the core of the Sun, then why does the photosphere of our Sun give off visible light?
The gamma rays lengthen as they lose energy moving from the inner layers of the sun to the outer layers.
What type of matter are the inner layers of the Sun composed of?
Plasma
Which of the stars shown below is hotter?

The blue star
Is the picture below an reflection nebula or an emission nebula?

Emission
A ________ _____________ is an extremely dense, hot core of a low-mass star (a "star corpse")
White dwarf
What class of star is likely to live the longest? What class is likely to live the shortest?
M-class, O-class
This layer of the Sun is where nuclear fusion takes place due to its extremely high temperatures and pressures.

Core
___________________________ is a measure of how bright a star appears from Earth, therefore it is dependent on the distance of the star
BONUS: If a star has an apparent magnitude of 10, is it brighter or dimmer than a star with an apparent magnitude of -10?
Apparent brightness
BONUS: Dimmer
A "failed star", which lacked the mass to become a true star, is also known as a _________________
Brown dwarf
A _______________ is a star that suddenly and dramatically increases in luminosity and then slowly returns to its original brightness
Nova
Massive stars will produce a __________ __________ supernova
Type II
This is the layer of the Sun that we actually see when we look at it.
BONUS: Sunspots on this layer appear dark because they are ___________________ than their surroundings
Photosphere
BONUS: cooler
What is the diagram pictured below called?

BONUS: What are most stars classified as on the diagram?
HR diagram
BONUS: Main sequence stars
A ___ __________________ star is an unstable, "teenaged" star which has not yet reached equilibrium between gravitational force and radiation pressure
T Tauri
Will the picture shown below lead to a type I or type II supernova?

Type I supernova
What event must take place to form extremely heavy elements, such as uranium?
Supernova
What are the three main products of hydrogen fusion?
BONUS: Which of these products is called the "ghost particle"?
Helium, neutrinos, and gamma rays
BONUS: neutrino
State the spectral class of the star shown below

BONUS: Where would such a star be found on the HR diagram?
M-class
BONUS: Main sequence, lower right corner
The cluster of stars shown below is a(n) _______________________

BONUS: Give one example of such a cluster that can be seen in the night sky
BONUS BONUS: Explain how the color of this star cluster relates to its age
Open cluster
BONUS: Pleiades
BONUS BONUS: It's still young enough to have O class stars
What two remnants are left from the death of a low-mass star?

White dwarf and planetary nebula
The collision of which two particles in nuclear fusion will lead to the creation of energy in the form of gamma rays?
Positron and electron in "annihilation"