Researchers have just uncovered some great solar observations that were conducted by a teenager in 1886. Juan Valderrama y Aguilar was only 17 when on September 10, 1886, he was able to witness a white-light solar flare, quite the rare event.
“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,” Valderrama wrote in his notes which were published in a French scientific Journal.
The amateur astronomer had a small telescope, with 6.6 centimeters (2.6 inches) of aperture purposely fitted with a neutral density filter. This allowed Valderrama to observe the Sun and record this event. According to the study, published in Solar Physics, Valderrama’s flare is chronologically the third one observed in History.
“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 realized,” co-author José Manuel Vaquero, from the University of Extremadura, said in a statement.
Solar flares are rapid increases in the brightness of regions of the Sun’s atmosphere. They are produced when there’s a sudden release of energy due to magnetic reconfiguration which releases light across the entire electromagnetic spectrum, although they are most commonly observed in X-rays.
White-light flares are one of the most extreme cases, as they are produced with such energy that even the photosphere of the Sun is affected and heated up, creating a bright white-light emission.
2
