Dear Professor, I have taken over 30 online astronomy courses, and yours is up there with the best. So easy to follow and understand. Thanks for this terrific lecture series.

Thanks! This helped a LOT! :) You did, however, mention at the end of the video that the sun was yellow, but it's actually white, which I learned from one of your other videos.

Good Video! Thanks a lot!

Nice facts, thanks.

In the schematic on the left side of the screen from 9:56 onwards you refer to a particle with two protons and one neutron as "tritium". It is not. Tritium contains one proton and two neutrons. A particle with two protons and one neutron is a helium-3 nucleus.

I am interested in the star birth : the moments after start of the fusion. Can you find any simulation of that for a main sequence star. I want to know the order of magnitude of, how long it takes between fusion start and the moment light reaches the surface. Seconds ? Minutes ? years ? millions of years ?

In the fusion part of the video, I might be wrong but I think you mistake 3He for tritium.

Where does the shock wave come from, prophessor? I guess from an exploding bunch of stars. The Chicken/Egg problem is a bitch.