NASA’s IRIS spots nanojetsDate: 23 September 2020 Tags: Space
Solar astronomers using NASA’s Interface Region Imaging Spectrograph (IRIS) mission have now discovered very fast and bursty nanojets, the telltale signature of reconnection-based nanoflares resulting in coronal heating.
It has long been hypothesized that the heating results from a myriad of tiny magnetic energy outbursts called nanoflares, driven by the fundamental process of magnetic reconnection.
The researchers combined the many observations with advanced simulations to recreate the events they saw on the Sun.
The models showed that the nanojets were a telltale signature of magnetic reconnection and nanoflares, contributing to coronal heating in the simulations.
Nanoflares are small explosions on the Sun, approximately nine orders of magnitude lower than solar flares, but they are difficult to spot.
They are very fast and tiny, meaning they are hard to pick out against the bright surface of the Sun. Nanojets are considered key evidence of the presence of nanoflares.
These telltale flashes are nanojets — heated plasma traveling so fast that they appear on images as bright thin lines seen within the magnetic loops on the Sun.
Each nanojet is believed to be initiated by a process known as magnetic reconnection where twisted magnetic fields explosively realign.
One reconnection can set off another reconnection, creating an avalanche of nanojets in the solar corona, a process that could create the energy that is heating the corona.