An extrasolar radiation belt, a la Van Allen, seen for the first time
- June 19, 2023
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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An extrasolar radiation belt, a la Van Allen, seen for the first time
Subject :Science and technology
Section: Space technology
Context:
- Astronomers describe the first radiation belt observed outside the solar system, using a coordinated array of 39 radio dishes from Hawaii to Germany.
Details:
- The images are persistent, intense radio emissions from an ultracool dwarf star revealed the presence of a cloud of high-energy electrons trapped in the object’s powerful magnetic field, forming a double-lobed structure.
The Radiation belts:
- Strong magnetic fields form a “magnetic bubble” around a planet called a magnetosphere, which can trap and accelerate particles to near the speed of light.
- All the planets in the solar system that have such magnetic fields, including the earth and Jupiter, have radiation belts.
- The earth’s radiation belt, known as the Van Allen belts, are large doughnut-shaped zones of high-energy particles captured from solar winds by the magnetic fields.
- This extrasolar radiation belt would be 10 million times brighter than Jupiter’s.
Notable features of Van Allen Radiation Belts are:
- Most of the particles that form the belts are thought to come from solar wind and other particles by cosmic rays.
- By trapping the solar wind, the magnetic field deflects those energetic particles and protects the atmosphere from destruction.
- The belts are located in the inner region of Earth’s magnetosphere.
- The belts trap energetic electrons and protons.
- Other nuclei, such as alpha particles, are less prevalent.
- The belts endanger satellites, which must have their sensitive components protected with adequate shielding if they spend significant time near that zone.
Magnetosphere:
- It is the region around a planet dominated by the planet’s magnetic field.
- Other planets in our solar system have magnetospheres, but Earth has the strongest one of all the rocky planets.
- The magnetosphere shields earth from solar and cosmic particle radiation, as well as erosion of the atmosphere by the solar wind – the constant flow of charged particles streaming off the sun.
Regions of the Earth’s Magnetosphere:
- Bow shock – It occurs when the magnetosphere of an Earth interacts with the nearby flowing ambient plasma such as the solar wind.
- Magneto sheath – It is the region of space between the magnetopause and the bow shock of a planet’s magnetosphere.
- Magnetopause – It is the boundary between the planet’s magnetic field and the solar wind.
- Magnetotail – The sun-facing side, or dayside, extends a distance of about six to 10 times the radius of the Earth.
- The side of the magnetosphere facing away from the sun, the night side stretches out into an immense magneto tail, which fluctuates in length and its exact length is not known, this extension of the magnetosphere.
- Northern tail lobe – The magnetosphere of the earth contains two lobes, referred to as the northern and southern tail lobes. Magnetic field lines in the northern tail lobe point towards the earth.
- Southern tail lobe – The magnetic field lines in the southern tail lobes point away from the earth. Usually, the tail lobes are almost empty, with few charged particles opposing the flow of the solar wind.
- Plasma sphere – The plasma sphere, or inner magnetosphere, is a region of the Earth’s magnetosphere consisting of low energy (cool) plasma.
- Solar winds – It is a stream of charged particles released from the upper atmosphere of the Sun, called the corona.