Jan. 17 (UPI) --
Scientists have precisely pinpointed the explosive release of energy that powered a series of solar flares -- a first.
The solar flares were originally recorded in 2017 by the Expanded Owens Valley Solar Array, EOVSA, a radio telescope operated by the New Jersey Institute of Technology.
While studying solar activity, the radio telescope spotted the birth of a new region of magnetic energy adjacent to an existing sunspot. The explosion of energy sent extremely hot plasma spewing from the solar atmosphere out into space.
Recently, scientists reexamined the data collected by the EOVSA, looking for unique patterns recorded in microwave spectrum.
Until now, scientists have only been able to study solar flares by examining the electromagnetic signatures registered at the photosphere, the sun's white light. By studying the microwave spectrum at short time scales, scientists were able to study the movement of energy within in the corona -- at the base of the solar flare.
Researchers published their breakthrough research this week in the journal Science.
We have been able to pinpoint the most critical location of the magnetic energy release in the corona,
study author Gregory Fleishman, a distinguished research professor of physics in NJIT's Center for Solar-Terrestrial Research, said in a news release. These are the first images that capture the microphysics of a flare -- the detailed chain of processes that occur on small spatial and time scales that enable the energy conversion.
By measuring the dissipation of magnetic energy in the wake of the coronal explosion and the subsequent increase in the electric field, scientists were able to use the law of energy conservation to calculate the thermal and kinetic energy that sends a solar flare's superheated plasma particles accelerating through the sun's upper atmosphere and out toward space.
Authors of the new study suggest the same analytical techniques they deployed to characterize solar flares -- combined with the technological capabilities of EOVSA -- could be used to study the origins of other powerful cosmic phenomena, like gamma ray bursts.
The thirteen antennas that make up the EOVSA can capture images across a wide spectrum of frequencies at extremely short time-scales.
Microwave emission is the only mechanism that is sensitive to the coronal magnetic field environment, so the unique, high-cadence EOVSA microwave spectral observations are the key to enabling this discovery of rapid changes in the magnetic field,
said study co-author Dale Gary, a distinguished professor of physics at NJIT and director of EOVSA. The measurement is possible because the high-energy electrons traveling in the coronal magnetic field dominantly emit their magnetic-sensitive radiation in the microwave range.
More than just examining the local explosion of energy that fuels solar flares, EOVSA instruments can be used to take a wide-angle view of the powerful shock waves that are propelled through space by coronal eruptions -- the kind of analysis that can help scientists better understand solar radiation and its impacts on Earth.
The connection of the flare-accelerated particles to those accelerated by shocks is an important piece in our understanding of which events are benign and which pose a serious threat,
Gary said.
Source: United Press International
(January 17, 2020 - 4:14 PM EST)
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