Astronomy Study Guide

Astronomy Study Guide

Quiz yourself for the Unit 3 Exam (Oct 2nd)

Big Bang

• 13.8 billion years ago
• Astronomers believe that the universe started as an infinitely dense point of energy ("singularity").
• not an explosion, rather it is the expansion of space itself

Discovery

Edwin Hubble was the astronomer that discovered how all the galaxies were accelerating away from each other. Space was literally spreading out and getting bigger. “If you could wind back time, like a movie in reverse, you could calculate when the universe began”

Multiple Choice

Who "discovered" the big bang?

• albert einstein

• edwin hubble

• isaac newton

Multiple Choice

How old is the universe?

• 13,800,000,000 years old

• 13.8 million years old

• 8.13 billion years old

• 150mil km per second

Fill in the Blanks

The big bang started as an infinitely

"singularity"

Multiple Choice

(from the video) How do stars form?

• gas and dust get pulled in by gravity and then nuclear fusion starts in the core

• they just form, since the big bang

• nuclear fusion happens because the gas and dust get blown outward

Multiple Choice

(from the video) stars fuse what element in their core?

• hydrogen into helium

• helium into hydrogen

• all of the elements

• star dust into heat

Multiple Choice

(from the video) what are the balancing forces in a star?

• outward pressure from the energy created in the fusion process and inward pull of gravity

• inward pressure from the energy create in the fusion process and outward push of gravity

Multiple Choice

(from the video) after a supernova explosion, what are the possible remains of that star?

• neutron star and black hole

• neutron star

• black hole

• white dwarf and main sequence star

CMRB

The CMRB (Cosmic Microwave Radiation Background) is the leftover heat from the Big Bang

distances

• astronomical unit (AU) - 150 million km. Which is about the distance from the Sun to the Earth
• Light Year (LY) - 9.46 trillion km. It is how far light can travel in one year.

HR Diagram

created by Hertzsprung and Russell to plot the stars by temperature and brightness

Multiple Choice

which stars are the hottest?

• white stars

• super giants

• dwarf stars

• blue stars

Multiple Choice

Most stars are _____________ and spend most of their life fusing hydrogen into helium.

• supergiants

• dwarf stars

• main sequence stars

Multiple Choice

Main sequence stars will eventually become what?

• giant stars

• supernovas

• black holes

Multiple Choice

which stars will last the longest?

• low mass stars

• high mass stars

Multiple Choice

which stars are the brightest?

• blue dwarfs

• giants

• red main sequence

• red supergiants

When stars die

they actually help the cycle of star formation and planet formation

study vocab too!