Topic: Red Giant Brightness Variations Still Mysterious

[sam]

Like everything else in the Universe, stars get old. As they become older, stars like our own Sun "puff up", becoming red giants for a period before finally settling down into white dwarfs. During this late period of their stellar lives, about 30% of low-mass red giants exhibit a curious variability in their brightness that remains unexplained to this day. A new survey of these types of red giants rules out most of the current explanations put forth, making it necessary to find a new theory for their behavior.

http://www.universetoday.com/2009/12/07/red-giant-brightness-variations-still-mysterious/

[Clive]

Speculative but plausible nevertheless.   

[Simon]

How old is our sun then?

[Clive]

Same age as the Earth Simon.  4.5 billion years. 

[Rik]

You mean we don't have an actual date where we could all sing to it?

[Simon]

It's pathetic, Rik. The money we spend in these astronomers, and they can't even tell us something as basic as that! 

[Rik]

I know, they're as bad as the NHS IT system.

[sam]

It's pathetic, Rik. The money we spend in these astronomers, and they can't even tell us something as basic as that! 

yeah but Clive didn't tell you the error bars either...

[sam]

I know, they're as bad as the NHS IT system.

baring that in mind, its 6000 years old. Now I feel as informed as the NHS.

[Simon]