While Jupiter is nowhere near massive enough to initiate fusion in its core, there are even more massive objects out there that fall just short of that achievement as well called brown dwarfs. Brown dwarfs, have a mass that places them between giant planets and small stars. They were only recently discovered in the 1990’s, but thousands are now known. More massive ones can fuse deuterium, and even lithium, but not hydrogen, distinguishing them from “normal” stars. Sort of.

Correction: In the illustration at 9:30, the numbers listed after the star names are the year of discovery, not distance.

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Table of Contents
Intermediate in Mass 1:22
Thousands Are Known 4:48
Cannot Fuse Hydrogen Like “Normal” Stars 8:46

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PHOTOS/VIDEOS
The sun in extreme ultraviolet en.wikipedia.org/wiki/File:The_Sun_in_extreme_ultraviolet.jpg [credit: NASA, ESA / Wikimedia Commons]
Jupiter www.spacetelescope.org/static/archives/images/screen/heic1410a.jpg [credit: NASA, ESA, and A. Simon (Goddard Space Flight Center)]
Forming a Planetary Gap www.spitzer.caltech.edu/video-audio/691-ssc2004-08v3-Forming-a-Planetary-Gap [credit: NASA/JPL-Caltech/R. Hurt (SSC/Caltech)]
Exoplanet uanews.org/sites/default/files/story-images/exoplanet.jpg [credit: NASA/JPL-Caltech]
A Trio of Brown Dwarfs (L/T/Y) www.nasa.gov/mission_pages/WISE/multimedia/pia14722.html [credit: NASA/JPL-Caltech]
Artist's concept of a T-type brown dwarf en.wikipedia.org/wiki/Brown_dwarf#/media/File:2MASSJ22282889-431026.jpg [credit: NASA/JPL-Caltech]
Brown Dwarf Gliese 229B en.wikipedia.org/wiki/File:Brown_Dwarf_Gliese_229B.jpg [credit: NASA / Wikimedia Commons]
Gliese 229B Spectrum - image provided by Phil Plait [credit: NASA/ESA/Hubble/Al Schultz et al]
Artist's vision of a T-dwarf en.wikipedia.org/wiki/Brown_dwarf#/media/File:T-dwarf-nasa-hurt.png [credit: R. Hurt/NASA - R. Hurt/NASA, Wikimedia Commons]
First Ultra-Cool WISE Brown Dwarf wise.ssl.berkeley.edu/gallery_firstbd.html [credit: NASA/JPL-Caltech/WISE Team]
Brown Dwarf Comparison www.nasa.gov/mission_pages/WISE/multimedia/pia12462.html [credit: NASA/JPL-Caltech/UCB]
Storms Expected on Brown Dwarfs www.spitzer.caltech.edu/images/5718-sig14-001-This-Just-In-Storms-Expected-on-Brown-Dwarfs [credit: NASA/JPL-Caltech/T. Pyle (IPAC)]
Stars and brown dwarfs closest to the Sun en.wikipedia.org/wiki/Luhman_16#/media/File:PIA18003-NASA-WISE-StarsNearSun-20140425-2.png [credit: NASA/Penn State University]

1. Introduction to Astronomy
2. Naked Eye Observations
3. Cycles in the Sky
4. Moon Phases
5. Eclipses
6. Telescopes
7. The Gravity of the Situation
8. Tides
9. Introduction to the Solar System
10. The Sun
11. The Earth
12. The Moon
13. Mercury
14. Venus
15. Mars
16. Jupiter
17. Jupiter's Moons
18. Saturn
19. Uranus & Neptune
20. Asteroids
21. Comets
22. The Oort Cloud
23. Meteors
24. Light
25. Distances
26. Stars
27. Exoplanets
28. Brown Dwarfs
29. Low Mass Stars
30. White Dwarfs & Planetary Nebulae
31. High Mass Stars
32. Neutron Stars
33. Black Holes
34. Binary and Multiple Stars
35. Star Clusters
36. Nebulae
37. The Milky Way
38. Galaxies, part 1
39. Galaxies, part 2
40. Gamma-Ray Bursts
41. Dark Matter
42. The Big Bang, Cosmology part 1
43. Dark Energy, Cosmology part 2
44. A Brief History of the Universe
45. Deep Time
46. Everything, The Universe...And Life
47. Explore The Solar System:

In this Crash Course series, marvel at the wonders of astronomy with your host for this intergalactic adventure, the Bad Astronomer himself -- Phil Plait. In just 40 short lessons, you will learn the basics of the oldest science known to humanity.

Be sure to check out links to relevant Photos in the description for each video.