Scientists spot sunspot with centre twice the size of Earth

Scientists and researchers from European Southern Observatory (ESO) in the month of January 2017 spotted the dark and contorted centre of a sunspot which is nearly twice the diameter of the Earth.

Researchers were able to spot this sunspot using Atacama Large Millimetre/submillimetre Array (ALMA) antennas located in Atacama Desert of northern Chile.

This discovery will be of great help for the astronomers to probe the physics of the nearest star.

The Finding
• Using ALMA antennas capabilities, astronomers imaged the millimetre wavelength light emitted by the Sun’s chromosphere which lies just above the photosphere that forms the visible surface of the Sun.
• They produced the images to study solar activity at longer wavelengths of light that are typically available to solar observatories on Earth.
• Scientists were able to observe an enormous sunspot using two of ALMA’s receiver bands at wavelengths of 1.25 millimetres and three millimetres.
• The images captured will help to reveal differences in temperature between parts of the Sun’s chromosphere and also understanding the heating and dynamics of the chromospheres.

About Sunspots
• Sunspots are darker and cooler areas on the surface of the sun in a region called the photosphere which has temperature of 5800 degrees Kelvin.
• They can be very large up to 50000 kilometres in diameter and have temperatures of about 3800 degrees Kelvin.
• Generally, they are dark in comparison with the brighter and hotter regions of the photosphere surrounding them.

Background
Throughout the ages, astronomers have studied the Sun and probed its dynamic surface and energetic atmosphere in varied ways and using many methodologies.

However, in order to achieve a fuller understanding, it was required to study the Sun across the entire electromagnetic spectrum including the millimetre and submillimetre portion that only ALMA could observe.