- Betelgeuse
The first direct image of the surface of a star other than our sun was reported by Andrea Dupree of Harvard-Smithsonian. The surface of the star, Betelgeuse, had been indirectly imaged earlier using speckle interferometry, in which many brief exposures are added up to make a composite image.
http://seds.lpl.arizona.edu/nodes/NODEv5n4-3.html
(Added: Wed Oct 30 2002)
- Definition of a Red Giant Star
Towards the end of a star's life, the temperature near the core rises and this causes the size of the star to expand. This is the fate of the sun in about 5 billion years.
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/971016.html
(Added: Wed Oct 30 2002)
- Red Giants
Red giants are stars that have exhausted their core hydrogen fuel, and are now in the helium-burning stage of their lives. The burning of helium is known as the triple alpha process. Red giants are much larger, more massive, and more diffuse than main sequence stars.
http://astrwww.astr.cwru.edu/Reference/RedGiants.html
(Added: Wed Oct 30 2002)
- Red Giants
After a few billion years the center of a star runs out of protons (nuclei of hydrogen atoms). What is left is a core or central region made of alphas (nuclei of helium atoms). The outer layers of the star still contain hydrogen, but they are not hot enough to fuse.
http://www.historyoftheuniverse.com/starold.html
(Added: Wed Oct 30 2002)
- Red Supergiants
A star of 15 solar masses exhausts its hydrogen in about one-thousandth the lifetime of our sun. It proceeds through the red giant phase, but when it reaches the triple-alpha process of nuclear fusion, it continues to burn for a time and expands to an even larger volume.
http://hyperphysics.phy-astr.gsu.edu/hbase/astro/redsup.html
(Added: Wed Oct 30 2002)
- Simulating a Pulsating Red Giant Star
This team has been studying the process of convection in the outer layers of stars like the sun for over a decade. Only in the last year, however, have both the supercomputers and the numerical methods allowed detailed simulations of the 3-D dynamics of entire model stars.
http://www.lcse.umn.edu/research/RedGiant/
(Added: Wed Oct 30 2002)
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