Title: Week 3: The Sun
Course: ASTRON103: The Evolving Universe: Stars, Galaxies, and Cosmology (001) DHH SU18 > Section: Week 3

Overview

Welcome to Week 3! The theme for this week is The Sun — the closest star to the Earth, and the source of almost all the energy that makes life on Earth possible.  We're going to start out by learning about the internal structure of the Sun, and how the surface regions of the Sun can produce weather out in space! We'll then look at the nuclear fusion reactions that provide the source of the Sun's immense power. To finish up, we'll turn our focus to the distant stars, figuring out what we can determine just by analyzing their light.

To get started, watch the video below where Rich and DK provide an overview of the week ahead. Then, dive into the Content (book and videos) and start planning how you'll undertake the weekly Activities (writing assignment, discussion forum, At Play in the Cosmos, weekly quiz, and longer-term project). To help you organize these tasks, we provide a Schedule and Checklist at the bottom of the page.

Content

Readings

The following readings from the Astronomy book cover the topics that we'll be focusing on this week:

- Chapter 15: The Sun: A Garden-Variety Star (sections 1, 3 & 4)
- Chapter 16: The Sun: A Nuclear Powerhouse (all sections)
- Chapter 17: Analyzing Starlight (all sections)

Two-Minute Universe

In these mini-lectures, Rich and DK cover a single topic from the book in a couple of minutes, by building up a page of notes and visuals summarizing the key facts and concepts you need to know. The summary page is available for download separately from the video, as a Portable Document Format (PDF) file).

- The Structure of the Sun (2m0s; video, summary)
- Energy and How the Sun is Powered (2m36s; video, summary)
- Mass, Energy, and Nuclear Forces (1m55s; video, summary)
- Fusion in the Sun (2m19s; video, summary)
- The Solar Cycle (1m52s; video, summary)
- Inside the Sun: Theory (2m3s; video, summary)
- Inside the Sun: Observation (5m9s; video, summary)
- The Brightness of Stars (5m26s; video, summary)
- The Colors of Stars (2m20s; video, summary)
- Spectra of Stars (4m26s; video, summary)
- Motion of Stars (2m50s; video, summary)

At Play in the Cosmos Flythroughs

In these flythroughs of the At Play in the Cosmos game, Rich provides commentary on the concepts being presented, highlights some pitfalls to be aware of, and tries to avoid being blown up by the bad guys.

- Mission 11: Defense for the Win (12m4s; hi-res video, lo-res video)
- Mission 12: Corporate Agenda (13m2s; hi-res video, lo-res video)
- Mission 13: Impending Doom (21m55s; hi-res video, lo-res video)
- Mission 14: Farther and Faster (9m49s; hi-res video, lo-res video)
- Mission 15: Hiding in Time (11m4s; hi-res video, lo-res video)

AstroGLU

In the AstroGLU (Astronomy Graduate Lectures for Undergraduates) series, the graduate students of the Department of Astronomy talk about some of the interesting research projects they're involved in.

- Dhanesh Krishnarao (DK) talking about Space Weather (18m23s; video)

Activities

Writing Assignment

This week's writing assignment focuses on the prospects for unlimited clean energy from fusion power, and what impact this development might have on society and the environment. Review the writing assignment and begin reflecting on relevant themes early during the week; summer courses move quickly, so it's to your advantage to think ahead.  The assignment is due by 11:59pm on Thursday, July 5^th (a day later than the usual deadline, to allow you to enjoy the July 4^th holiday).

At Play in the Cosmos Missions

This week's game missions take you on the run from the dastardly Corporation. We suggest you try these missions by yourself at first, and then dip into Rich's flythroughs (see above) for guidance and commentary. The deadline for completing the missions is 11:59 PM on Friday, July 6^th.

Discussion

This week's discussion focuses on the many ways in which the Sun can be harmful to life here on Earth.  You need to make an initial post in order to see other students' responses, and you must make a total of three posts by the deadline of 11:59 PM on Saturday, July 7^th.

Quiz

This week's quiz tests your understanding of the topics covered throughout the week, and is drawn from Chapters 15, 16 and 17 of the Astronomy book. It consists of ten questions with written answers. You can take it anytime up until 11:59pm on Sunday, July 8^th.

Multi-Week Project

The second multi-week project lets you show off your creative side, by having you design a star-finding pamphlet to share with your friends and family. The project is due at the end of Week 4, but you should get an early start on it, as this course will be moving along quickly.

Weekly Schedule & Checklist

Use the schedule below to pace yourself during this week, and the check-boxes to mark off your progress.  Each horizontal line represents an important task and the corresponding days on which you should focus on that task. It is important that you keep pace to perform well on the weekly quiz, and to participate fully in the discussion forum.

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