Thanks for the info nkalanaga

That was really interesting so the atmosphere of yellow
hypergiant stars is unstable and as a result they are
probably not yellow for long. I think I understand now
what your saying about stars colours because I have
been told in trillions of years to come if you can see a red
that is too red for the human eye to see you would
notice its full of dead stars.

cheers

Karl

True.  The "red too red to see" would be infrared, or heat, which was first discovered with a thermometer.  A scientist, using a prism to show the Solar spectrum, put his thermometer in the dark area beyond red, and found that there was a lot of energy there.  Just like an incandescent light bulb, red stars are most energetic in the infrared.

This has two effects on potentially habitable planets around such stars.  First, the habitable zone has to be calculated from the bolometric (literally, "heat"), or total, luminosity, or the planet will be placed too close and will overheat.  That means that the visible light will look considerably dimmer than for a Sun-like star, where most of the energy is in visible light.

It also means that, just like the light bulb, the red dwarf will look white to an observer, as long as there is no "true white" light to compare it to.  In fact, the average American 100 watt bulb is about the same temperature, and color, as an M6 star.  One source says any star over about M8 would look white to a nearby observer.  The bright red "red dwarfs" often seen in art wouldn't look that way at all from a nearby planet.

N Kalanaga 

Wow thats amazing. Thanks for the info there is one thing
I have wanted to ask you for a long time what is your
favourite star or favourite type of star (mines Eta Carinae
as it looks so unusual and reminds me of a brain.

Cheers

Karl

karl.garnham1 wrote: Hi Solar Voyager VY Canis Majoris is No longer the biggest star in Diametre in the universe it has been toppled by these stars. NML Cygni      V838 Monocerotis      KW Sagittarii      KY Cygni      and after all these comes VY Canis Majoris The Biggest Stars in mass are R136a1 R136a2 R136c Someone needs to give these guys a decent name imagine what they would say if they knew what people have called them. Karl

This is something worth knowing, glad i bumped into this thread because i was watching a documentary of how the world 1st telescope was made and how they came to know there exists other millions of galaxies with billions of stars out in space, I wonder how hot those stars are.

Thanks for sharing! This is amazing! 

JanL wrote: Karl, thanks for the research that you did on this.  It is extremely hard to realize how large stars can be.  Can't imagine a star that would engulf all planets through Jupiter and really up close and personal with Saturn.  Jan