Astronomers spot a surprising solar eruption that maintains constant temperature

Source: The post is based on the article “Astronomers spot a surprising solar eruption that maintains constant temperature”  published in PIB on 12th June 2023

What is the News?

Scientists in India have found that a solar eruption that occurred in July 2017 has maintained its temperature for nearly six years.

What are Coronal Mass Ejections (CMEs)?

Coronal Mass Ejections (CMEs) are large-scale eruptions of charged particles (plasma) and magnetic fields from the solar atmosphere into space. 

They can disrupt a range of ground- and space-based technologies and satellites on Earth. Thus, it is crucial to understand their evolution and propagation through interplanetary space. 

There is a wide range of plasma temperatures within CMEs, from cold chromospheric material (around 104 K) to hot plasma (around 107 K). 

When CMEs propagate, several processes can exchange energy (electrical, kinetic, potential, thermal, and so on.), thereby heating or cooling the plasma. 

To understand the underlying processes, it is important to study the evolution of thermodynamic properties (such as density, temperature, thermal pressure, etc.) of CMEs. This will help the human ability to monitor space weather.

What did the scientists find about Coronal Mass Ejections (CMEs)?

Scientists have found that a solar eruption that occurred in July 2017 has maintained its temperature for nearly six years.

They observed that despite the core expanding, which would usually cause cooling, the temperature remained constant as it moved from 1.05 to 1.35 times the radius of the sun. They used data from ground-based and space-based instruments to support these findings.

Additionally, they observed that the density of the core decreased by about 3.6 times as it moved outward.

Based on these observations, the scientists concluded that the expansion of the core behaved more like an isothermal process (constant temperature) rather than an adiabatic process (where heat exchange occurs).

What are the future prospects of this discovery?

In the future, India’s Aditya-L1 mission, equipped with the visible emission line coronagraph (VELC), will provide more data about CMEs in the inner corona. 

Analyzing this data will offer new insights into the evolution of CME properties in that region.