SCIENCE

131 years ago, young Spanish astronomer records solar flare

The description of the sudden flash in a sunspot seen on September 10, 1886, along with a picture was published in French journal L’Astronomie over a century ago.

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, 1886, along with a picture was published in French journal L’Astronomie 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.

This is his description

“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 Sun’s 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.

‘Extraordinary for a kid’

“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 Mr. Vaquero.
Satellites have detected powerful solar flares in the last two months, but this phenomenon has been recorded for over a century. On 10 September 1886, at the age of just 17, a young amateur astronomer using a modest telescope observed from Madrid one of these sudden flashes in a sunspot. He wrote about what he saw, drew a picture of it, and published the data in a French scientific journal. This is what researchers from the Instituto de Astrofísica de Canarias and the Universidad de Extremadura have recently found.
"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. 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."
In these words, Juan Valderrama y Aguilar, a 17-year-old amateur astronomer, described what he saw from Madrid on 10 September 1886 with his small telescope, with an aperture of just 6.6 cm and equipped with a neutral density filter to dim the solar light. The young man wrote down the details of his observations, made a drawing of the bright flash he had seen coming from the sunspot, and sent all the information to the French journal L'Astronomie, which did not hesitate to publish it.
"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," explains José Manuel Vaquero, a lecturer at the University of Extremadura and co-author of an article about the event, now being published in the journal Solar Physics, to Sinc.