(ORDO NEWS) — In a new study, scientists led by Patrick Antolin of the University of Northumbria, United Kingdom, report the first-ever conclusive discovery of nanojets – bright, narrow streams of plasma moving perpendicular to magnetic structures in the solar corona – in a process that can prove the existence of nanoflares – hypothetical events that can cause heating of the solar corona to extremely high temperatures, which has not yet received an unambiguous scientific explanation.
In an attempt to understand why the temperature of the Sun’s atmosphere is much higher than its surface temperature, and to determine in favor of one of the many hypotheses about the reasons for this heating, Antolin’s team used NASA’s Interface Region Imaging Spectrograph (IRIS) mission. The IRIS instrument works in tandem with a high-resolution imaging device to provide a detailed view of events on the Sun that are difficult to observe with other instruments.
Nanoflares are small explosions on the Sun – but very difficult to spot. They are tiny in size and happen very quickly, so they are difficult to distinguish against the background of the bright, bubbling surface of our star. On April 3, 2014, during an event called coronal rain – when streams of cooled plasma fell from the corona back onto the Sun’s surface (see video) – researchers noticed bright jets appearing towards the end of this event.
These characteristic flares are called nanojets, and they are incandescent streams of plasma moving so fast that they appear in images as bright thin lines observed inside magnetic loops on the Sun. Nanojets are considered the most compelling evidence for the existence of nanoflares. It is believed that each nanojet arises in the process of reconnecting the lines of the solar magnetic field.
Each such reconnection can initiate another reconnection in a chain process, which in general can explain the release of energy in an amount sufficient to explain the overheating of the solar corona, the authors explained.
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