Lovely Loops

The upper one of a pair of new, solar active regions that just rotated into view of SDO offered a beautiful profile view of cascading loops spiraling above it (Jan. 15-16, 2012) following a solar flare eruption. These loop structures are made of superheated plasma, just one of which is the size of several Earths. With its ability to capture the Sun in amazing detail, SDO observed it all in extreme ultraviolet light.



The upper atmosphere of the Sun is dominated by plasma filled magnetic loops (coronal loops) whose temperature and pressure vary over a wide range. The appearance of coronal loops follows the emergence of magnetic flux, which is generated by dynamo processes inside the Sun. Emerging flux regions (EFRs) appear when magnetic flux bundles emerge from the solar interior through the photosphere and into the upper atmosphere (chromosphere and the corona). The characteristic feature of EFR is the -shaped loops (created by the magnetic buoyancy/Parker instability), they appear as developing bipolar sunspots in magnetograms, and as arch filament systems in . EFRs interact with pre-existing magnetic fields in the corona and produce small flares (plasma heating) and collimated plasma jets. The GIFs above show multiple energetic jets in three different wavelengths. The light has been colorized in red, green and blue, corresponding to three coronal temperature regimes ranging from ~0.8Mk to 2MK. 

Image Credit: SDO/U. Aberystwyth

This is plasma

Plasma is used in nuclear fusion reactors. Inside the reactor, gas is heated to a temperature many times hotter than the sun. The fuel gets so energetic that the ions and electrons split, creating the fourth state of matter: plasma, an ionised gas.

But controlling a substance this hot is hard, and inside fusion reactors it has to be somehow maintained in a certain area. Because the plasma is charged, it responds to a magnetic field, like this:

As a result, fusion reactors work like magnetic bottles to contain the energy. Watch this demo in full from the 2016 CHRISTMAS LECTURES with Saiful Islam.


Plasma Arc Lighter!

The life cycle of a Sun-like star

This image tracks the life of a Sun-like star, from its birth on the left side of the frame to its evolution into a red giant star on the right. On the left the star is seen as a protostar, embedded within a dusty disc of material as it forms. It later becomes a star like our Sun. After spending the majority of its life in this stage, the star’s core begins to gradually heat up, the star expands and becomes redder until it transforms into a red giant.

Following this stage, the star will push its outer layers into the surrounding space to form an object known as a planetary nebula, while the core of the star itself will cool into a small, dense remnant called a white dwarf star.

Marked on the lower timeline are where our Sun and solar twins 18 Sco and HIP 102152 are in this life cycle. The Sun is 4.6 billion years old and 18 Sco is 2.9 billion years old, while the oldest solar twin is some 8.2 billion years old —  the oldest solar twin ever identified. By studying HIP 102152, we can get a glimpse of what the future holds for our Sun.

Credit: ESO / M. Kornmesser