Stars, black holes and galaxies
Our universe is defined by stars. This topic explores how they came to be and where they end up. This includes a discussion of black holes and galaxies.
This course contains 4 segments:
Life and death of stars
Stars begin when material drifting in space condenses due to gravity to be dense enough for fusion to occur. Depending on the volume and make-up of this material, the star could then develop into very different things--from supernovae, to neutron stars, to black holes. This tutorial explores the life of stars and will have you appreciating the grand weirdness of our reality.
Quasars and galactic collisions
Quasars are the brightest objects in the universe. The gamma rays from them could sterilize a solar system (i.e. obliterate life). What do we think these objects are? Why don't we see any close by (which we should be thankful for)? Could they tell us what our own galaxy may have been like 1 billion or so years ago?
Stellar parallax
We've talked a lot about distances to stars, but how do we know? Stellar parallax--which looks at how much a star shifts in the sky when Earth is at various points in its orbit--is the oldest technique we have for measuring how far stars are. It is great for "nearby" stars even with precise instruments (i.e, in our part of our galaxy). To measure distance further, we have to start thinking about Cepheid variables (other tutorial).
Cepheid variables
Stellar parallax can be used for "nearby" stars, but what if we want to measure further out? Well this tutorial will expose you to a class of stars that helps us do this. Cepheids are large, bright, variable stars that are visible in other galaxies. We know how bright they should be and can gauge how far they are by how bright they look to us.
Get a Reminder
Rating | Not enough ratings |
---|---|
Length | 4 segments |
Starts | On Demand (Start anytime) |
Cost | Free |
From | Khan Academy |
Download Videos | On all desktop and mobile devices |
Language | English |
Subjects | Science |
Tags | Science Cosmology and astronomy |
Get a Reminder
Similar Courses
Careers
An overview of related careers and their average salaries in the US. Bars indicate income percentile.
Vice President Lean Six Sigma Black Belt Manager $104k
Lean Six Sigma Black Belt Expert Manager $113k
Six Sigma & Lean Black Belt. Category Management & Operations $127k
Six Sigma Black Belt & Organizational Change Specialist $131k
Lean Six Sigma Black Belt / Continuous Improvement Engineer $132k
Project Manager/Black Belt $134k
Master Supervisor Six Sigma Black Belt $135k
Master Project Manager, Six Sigma Black Belt, Global Shared Services $141k
Supply Chain Project Manager / Black Belt $151k
Master Statistician/Lean Six Sigma Black Belt Lead $174k
Master Supervisor Black Belt $209k
Master Regional Black Belt Manager $256k
Write a review
Your opinion matters. Tell us what you think.
Please login to leave a review
Rating | Not enough ratings |
---|---|
Length | 4 segments |
Starts | On Demand (Start anytime) |
Cost | Free |
From | Khan Academy |
Download Videos | On all desktop and mobile devices |
Language | English |
Subjects | Science |
Tags | Science Cosmology and astronomy |
Similar Courses
Sorted by relevance
Like this course?
Here's what to do next:
- Save this course for later
- Get more details from the course provider
- Enroll in this course