You're describing prominences, which are huge, bright, arching structures of gas extending from the Sun's surface. They're often called "loops" because they can form arches that loop back onto the Sun's surface.

Here's some more information about prominences:

* Composition: Prominences are primarily composed of hydrogen and helium, the same elements that make up the Sun's atmosphere.

* Formation: They form when magnetic fields in the Sun's corona channel and confine hot plasma, creating these giant loops.

* Temperature: Interestingly, even though prominences are embedded in the extremely hot corona (millions of degrees Celsius), the material within them is actually much cooler, around 10,000 degrees Celsius.

* Lifespan: Prominences can last for hours, days, or even weeks, with some of the longest-lived ones stretching across vast distances.

* Eruption: Sometimes, prominences can become unstable and erupt, spewing out huge amounts of plasma into space. This can cause solar flares and coronal mass ejections (CMEs), which can affect Earth.

Hopefully, this explanation helps!