Solar Eclipses Reveal Iron Line In Solar Corona
Greenbelt MD (SPX) Jan 05, 2010
Solar physicists attempting to unlock the mysteries of the solar corona have found another piece of the puzzle by observing the Sun's outer atmosphere during eclipses.
Ground-based observations reveal the first images of the solar corona in the near-infrared emission line of highly ionized iron, or Fe XI 789.2 nm.
The observations were taken during total solar eclipses in 2006, 2008, and 2009 by astrophysicist Adrian Daw of NASA's Goddard Space Flight Center in Greenbelt, Md., with an international team of scientists led by Shadia Habbal from the University of Hawaii's Institute for Astronomy (IfA).
"The first image of the corona in Fe XI 789.2 nm was taken during the total solar eclipse of March 29, 2006," said Daw.
The images revealed some surprises. Most notably, that the emission extends out at least three solar radii - that's one-and-a-half times the Sun's width at its equator, or middle - above the surface of the Sun, and that there are localized regions of enhanced density for these iron ions.
Combined with observations of other iron charge states, the observations yield the two-dimensional distribution of electron temperature and charge-state measurements for the first time, and establish the first direct link between the distribution of charge states in the corona and in interplanetary space.
"These are the first such maps of the 2-D distribution of coronal electron temperature and ion charge state," said Daw.
Mapping the distribution of electron temperature and iron charge states in the corona with total solar eclipse observations represents an important step in understanding the solar corona and how space weather impacts Earth.
The scientists' results were presented at the American Astronomical Society meeting on January 4 in Washington and published in the January issue of the Astrophysical Journal.
Share This Article With Planet Earth
Solar Science News at SpaceDaily
Naval Research Lab Studies Solar Storms
Washington DC (AFNS) Dec 30, 2009
Imagine a threat to the global community with the potential to damage communication satellites, interrupt navigation systems, shut down regional power grids, impede oil and gas exploration, expose aircraft crews to high levels of radiation, and endanger the lives of astronauts. That threat exists, but it's not from any well-organized terrorist group. It's from t ... read more
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2009 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement|