A huge portion of the Sun has broken off from its surface, and is now circulating around the north pole of the star. NASA's Solar Dynamics Observatory captured the phenomenon, and space weather physicist Dr Tamitha Skov tweeted about it. 


According to Dr Tamitha, material from a northern prominence of the Sun broke away from the main filament. 




What is a solar prominence?


A solar prominence is a large, bright feature extending outward from the Sun's surface, is anchored to the Sun's surface in the photosphere, and extends outwards into the Sun's outer atmosphere, the corona, according to NASA. A prominence is a dense cloud of ionised gas and the Sun's analogue of Earth's clouds. Prominences are loop-like structures. 


Skov tweeted that material from a northern prominence broke away from the main filament. 


What is a solar filament?


A solar filament is a dark line or curve, and a huge arc of plasma (electrified gas) in the Sun's atmosphere, which appears dark because it is not as hot as the Sun's surface behind it, according to the UCAR Center for Science Education. 


Difference between a solar prominence and filament


When loops of ionised gas are viewed from the edge of the Sun against the darkness of space, they are called prominences. However, when these loops are observed against the background of the Sun, they are called filaments. 


Vortex motion around Sun’s north pole


The prominence which recently broke off from the Sun is circulating in a "massive polar vortex" around the north pole of the star, according to Skov. This means that there is a vortex motion in the Sun's north polar region. The motion of a rotating mass of fluid is known as vortex motion. Here, the fluid is plasma. 


Unusual activities at certain regions of the Sun 


According to experts, unusual activities occur at the Sun's 55 degree latitudes once every 11-year solar cycle, a New York Post report said. 


According to an article published by Space.com, Scott McIntosh, a solar physicist and deputy director at the National Center for Atmospheric Research in Boulder, Colorado, said that he has never seen a vortex like this. He also said that something odd is happening at the Sun's 55 degree latitudes with clockwork regularity once every solar cycle.


What could have caused the unusual phenomenon?


McIntosh said a prominence like this appears exactly at the 55 degree latitude around the Sun's polar crows every 11 years. According to scientists, this phenomenon could be related to the reversal of the Sun's magnetic field that happens once every solar cycle. 


Quoting McIntosh, the Space.com article said a prominence forms at the 55 degree latitude once every solar cycle, and starts to march up to the solar poles. He said it is "very curious" and that there is a big "why" question around it. 


While such filaments have been observed in the past, the recent phenomenon is first-of-its-kind. 


The Sun's polar regions play an important role in the generation of the star's magnetic field, and this, in turn, drives the star's 11-year cycle of activity, the article said. 


Scientists believe that the phenomenon has something to do with the Sun's magnetic field. However, the actual cause remains a mystery due to Earth's limited view of the Sun, the article said.


This is because people on Earth can view the Sun only from the "ecliptic plane" or the geometric plane in which Earth's orbit is present. 


The European Space Agency's (ESA's) Solar Orbiter Mission, which captures images of the Sun beyond the ecliptic plane, might provide some clues which could help scientists unravel the mystery behind this unusual phenomenon.