corona tagged posts

For billions of years, the Milky Way’s largest satellite galaxies—the Large and Small Magellanic Clouds—have followed a perilous journey. Orbiting one another as they are pulled in toward our home galaxy, they have begun to unravel, leaving behind trails of gaseous debris. And yet—to the puzzlement of astronomers—these dwarf galaxies remain intact, with ongoing vigorous star formation.

“A lot of people were struggling to explain how these streams of material could be there,” said Dhanesh Krishnarao, assistant professor at Colorado College. “If this gas was removed from these galaxies, how are they still forming stars?”

With the help of data from NASA’s Hubble Space Telescope and a retired satellite called the Far Ultraviolet Spectroscopic Explorer (FUSE), a t...

The Sun’s extremely hot outer layer, the corona, has a very different chemical composition from the cooler inner layers, but the reason for this has puzzled scientists for decades.

One explanation is that, in the middle layer (the chromosphere), magnetic waves exert a force that separates the Sun’s plasma into different components, so that only the ion particles are transported into the corona, while leaving neutral particles behind (thus leading to a build-up of elements such as iron, silicon and magnesium in the outer atmosphere).

Now, in a new study published in The Astrophysical Journal, researchers combined observations from a telescope in New Mexico, the United States, with satellites located near Earth to identify a link between magnetic waves in the chromosphere and area...

Helium is the second most abundant element in the universe after hydrogen. But scientists aren’t sure just how much there actually is in the Sun’s atmosphere, where it is hard to measure. Knowing the amount of helium in the solar atmosphere is important to understanding the origin and acceleration of the solar wind—the constant stream of charged particles from the Sun.

In 2009, NASA launched a sounding rocket investigation to measure helium in the extended solar atmosphere—the first time we’ve gathered a full global map...

The SwRI-led team processed solar coronal images to reveal universal gusts, jets and streams (green) emanating from the Sun, offering a possible explanation for the gusty solar wind found around Earth. The upcoming Parker Solar Probe will fly through this riotous torrent as the first spacecraft ever designed to ‘touch’ the Sun.
Credit: Image Courtesy of NASA/SwRI/STEREO

A SWRI-led team discovered never-before-detected, fine-grained structures in the Sun’s outer atmosphere, or corona. The team imaged this critical region in detail using sophisticated software techniques and longer exposures from the COR-2 camera on board NASA’s Solar and Terrestrial Relations Observatory-A (STEREO-A).

The Sun’s outer corona is the source of the solar wind, the stream of charged particles that flow outward fr...