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

Q: How long does it take energy from the core of the sun to reach the photosphere? Describe the steps involved and approximately how much time each step takes.

Q: How do we know that the Carrington Event of 1859 was as powerful as it was without having the modern satellites we do today to monitor the Sun?

Q: Briefly describe in your own words what hydrostatic equilibrium means.

Q: Two stars, Alpha and Beta, have different apparent brightnesses but identical luminosities.

If Alpha is 15 lightyears away and appears 25 times brighter in the sky than Beta, how far away is Beta in lightyears?

Briefly explain how you got your answer.

Q: You measure the magnitude of two stars, Alpha and Beta.

Alpha has a magnitude of 16.

Beta has a magnitude of 8.5.

Which star is brighter? By how much?

Q: The Sun converts 4 × 10^9 kg of mass to energy every second.

How many years would it take the Sun to convert a mass equal to the mass of Earth to energy?

Q: You measure the magnitude of a Red Giant star in a red filter and then a blue filter.

Which filter will result in a lower magnitude measurement? Explain.

Q: If you were especially worried about the harmful effects of space weather, what might be an ideal location to live on Earth? Why?

Q: The average Coronal Mass Ejection (CME) takes 3 days (72 hours) to reach Earth.

Assuming the CME travels at a constant speed, what is the average speed of the CME as it travels to Earth in units of kilometers per second (km/s)?

Q: Consider 3 stars, Gamma, Omega, and Delta, each moving at a speed of 100 km/s. Gamma moves in a way so that its motion is entirely perpendicular to our line of sight (i.e. it moves across the sky as viewed from Earth). Omega moves in a way so that it is moving entirely away from us. Delta moves in a way so that it is moving towards us, but at an angle of 30 degrees from our line of sight (i.e. it moves towards us and also cross the sky).

Describe how the Doppler Effect would be observed for each of these three stars (if at all). Be sure to specify if the light will be redshifted, blueshifted, or none and explain why.