From Speaking of Hubble: “The Life Cycles of Stars” 


April 5, 2012
Jason Kalirai

“As you stargaze over the next few weeks, keep in mind that most of those tiny points of light scattered across the sky are burning infernos of gas. These stars are very much like the Sun. Some are bigger and more powerful, and some smaller. But they are not constant. Stars change over time, and evolve into different states. Understanding this process of stellar evolution is my primary passion in astronomy, and was the focus of a meeting we just held at the Space Telescope Science Institute, ‘The Mass Loss Return from Stars to Galaxies’.

A low-mass star, like our Sun, will slowly burn its hydrogen into helium, and remain in a state of equilibrium for billions of years. This is great for us on Earth, since it provides us with a stable environment. But in about 4 billion years, the Sun will expand and begin to lose its outer layers. During this stage, called the red giant phase, the Sun will be so large that it will encompass the Earth’s orbit around it, crisping our planet!

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(Wikipedia)The size of the current Sun (now in the main sequence) compared to its estimated size during its red giant phase in the future. No image credit

Interested? See the full article here.

Space Telescope Science Institute (STScI) — home of science program selection, grant administration, planning, scheduling, and public outreach activities for the Hubble Space Telescope (HST). STScI provides data archive and distribution for all of NASA’s optical/UV missions, including HST. STScI is also the science and operations center for the 6.5m James Webb Space Telescope (JWST).