The Sun -Startling New Discoveries
"We've seen many new and unexpected things. For that reason alone, the recently launched Hinode spacecraft, one of the latest observatories to probe the sun from afar, is already a success," says Leon Golub, senior astrophysicist at the Harvard-Smithsonian Center for Astrophysics. "Everything we thought we knew about X-ray images of the sun is out of date."
One of three instruments on board Hinode is the X-Ray Telescope (XRT), which was developed and built by the Smithsonian Astrophysical Observatory and the Japan Aerospace Exploration Agency.
The XRT collects X-rays emitted from the sun's corona - the hot, tenuous outer layer that extends from the sun's visible surface into the inner solar system. Gas in the solar corona reaches temperatures of millions of degrees. The energy source that heats the corona is a puzzle. The sun's surface is only 10,000 degrees Fahrenheit, while the corona is more than 100 times hotter.
The XRT has spied twisted and tangled magnetic fields that store huge amounts of energy. When those complicated magnetic structures relax to simpler configurations, a huge amount of energy is released. That energy heats the corona and powers solar eruptions like flares and coronal mass ejections.
Ultimately, the knowledge gained from the XRT and Hinode's other two instruments may help astronomers to forecast solar eruptions and the associated "space weather."
Comments