London: Scientists have uncovered a research paper describing a solar flare that was observed by a 17- year-old amateur astronomer, with a modest telescope 131 years ago in Spain.
The description of the sudden flash in a sunspot seen on September 10 in 1886, along with a picture had been published in the French journal LAstronomie over a century ago.
Juan Valderrama y Aguilar was equipped with a small telescope, with an aperture of just 6.6 cm and a neutral density filter to dim the solar light.
“The case of Valderrama is very unique, as he was the only person in the world more than a century ago to observe a relatively rare phenomenon: a white-light solar flare. And until now no one had realised,” said Jose Manuel Vaquero, a lecturer at the University of Extremadura in Spain.
“A huge, beautiful sunspot was formed from yesterday to today. It is elongated due to its proximity to the limb by looking at it carefully I noticed an extraordinary phenomenon on her, on the penumbra to the west of the nucleus, and almost in contact with it, a very bright object was distinguishable producing a shadow clearly visible on the sunspot penumbra,” Valderrama y Aguilar wrote to describe his observations.
“This object had an almost circular shape, and a light beam came out from its eastern part that crossed the sunspot to the south of the nucleus, producing a shadow on the penumbra that was lost in the large mass of faculae surrounding the eastern extreme of the sunspot,” he wrote.
A flare is a sudden increase in the brightness of a region of the Suns atmosphere.
It occurs in the outermost layers when the configuration of the magnetic field changes and releases energy, which can be detected in several bands of the electromagnetic spectrum as visible or ultraviolet light, although they are most commonly recorded in X-rays.
Scientists studying solar flares employ special satellites and instruments that do not operate with visible light, but a white-light flare can be observed with normal telescopes that use visible light, as Valderrama y Aguilar did in 1886.
“It is extraordinary that in the Spain of the 19th century, a 17-year old kid would make such a scientific discovery, and it is even more impressive that he had the courage of submitting it for publication to a foreign scientific journal,” said Jorge Sanchez Almeida, of the Instituto de Astrofisica de Canarias (IAC).
“Furthermore, the white-light flare observed by Valderrama is, chronologically, the third one recorded in the history of solar physics,” said Vaquero.
The first solar flare was recorded by British astronomer Richard C Carrington on September 1, 1859, and the second was described on November 13, 1872 by the Italian Pietro Angelo Secchi.
The two flares were widely known in their day, as they sparked a debate on whether or not they could have an impact on Earth.