A new study has been published that outlines data captured by researchers that may be the first complete observation of a solar nanoflare. The study marks the first time scientists have captured the full lifecycle of what may be a putative nanoflare ranging from its first bright origins to its demise. A nanoflare is a tiny eruption on the Sun’s surface, which is about one-billionth of the size of a normal solar flare.
Researchers have been trying to discover more details on nanoflares because they are thought to be responsible for heating the solar corona to its incredibly high temperature. While this marks the first time the complete lifecycle of a nanoflare has been accomplished, researchers predicted they existed back in 1972 in an effort to solve the mystery of coronal heating.
Scientists wanted to know how the Sun’s outer atmosphere, known as the corona, can reach such incredibly high temperatures despite that it’s further away from the solar core. The corona is millions of degrees hotter than the layers beneath it. Part of the challenge in explaining the corona’s high temperatures was that no one had ever observed a nanoflare.
Nanoflares are very small and very brief, and telescopes have only recently become powerful enough to observe them. Nanoflares have something in common with a regular solar flare in that the nanoflare is created by magnetic reconnection. Magnetic reconnection is triggered by the explosive realignment of magnetic field lines able to instantly heat “cool” plasma to super-hot temperatures.
To spot magnetic reconnection, scientists looked for intense heat among far cooler surroundings. To confirm the observation was of a nanoflare, the object also had to heat the corona. Researchers used images taken by the NASA Interference Region Imaging Spectrograph satellite known as IRIS for the study.
While looking at very small and bright loops that are about 60 miles across, it was discovered the loops were millions of degrees hotter than their surroundings. After intense study, it was determined that the only heating mechanism that can produce the effect noted had to come from magnetic reconnection. The researchers are still working on confirmation that the objects being studied occur often enough all over the sun to account for the corona’s extreme heat.