Astronomy 102 – Exam 2 – Study Guide

Go over the HW problems (15%), labs (20%) and quizzes (15%).

Know relevant terms to prepare for the fill-in-the-black questions.

Know how to identify images of dark nebulas, emission nebulas, molecular clouds, reflection nebulas, proto-planetary disk, planetary nebulas and supernova remnants.

What is a brown dwarf?
What is white dwarf?
What is a black dwarf?
What is a red dwarf? (hint: this is not the British Sci-Fi Comedy)

What is the mass range of normal stars?

What is the mass range of brown dwarfs & white dwarfs?

What support stars (main sequence, red giant, white dwarf, neutron star) from collapsing?

What evolutionary stages will very low, low, intermediate and high mass star go through from beginning to end?

Know how to calculate the main sequence lifetime of a star.

What happens to a star when it runs out of hydrogen?

What are planetary nebulas and what type of stars will from them?

Know how the Sun will evolve from its birth on the main sequence to its death as a white dwarf and understand what is happening in the core and surface of the Sun.

What are the mass demographics of stars?

What process causes interstellar clouds to glow?

How long do stars take to form?  When do stars join the main sequence?

Where are stars born? What conditions do stars need to form?

What is a protostar?

What stuff is in the interstellar medium?

What elements can different mass stars produce?

How do interstellar gas and dust respond to starlight?

What regulates the temperature of a star?

What types of stars maintain hydrostatic equilibrium?

What do the stars in a cluster tell us about the star cluster itself?

What is the difference between a nova and a supernova?

What is the difference between Type Ia and Type II supernovas?

What types of stars can rotate very fast?

What would happen if the Sun turned into a black hole?

What are the Schwarzschild Radius and the Event Horizon?

What is at the very center of a black hole?

How can the mass of a Black Hole be estimated?

Don’t forget the material from Exam#1, especially the following concepts:

Know the different types of light object emits when heated to different temperatures

Know Wien’s Law and how it apply it
Know Stefan-Boltzmann’s Law and how to apply it
Know all three of Kirchoff’s Laws.

Know how the brightness of an object will change, when its distance changes


Challenge Problem (14%) – Suppose that our Sun was a different type of star (the stellar mass will be given on the exam). How would that affect us here on the Earth? Include a description of the star, the lifetime of the star, the type of light received by the Earth, the evolution of the star and what events would we experience from the time on the Main Sequence to the death of the star. Explain with scientific reasoning and support your claims with scientific arguments. The HR diagram and other figures will be provided on the exam.