National Astronomical Observatory of Japan



A Shot of a Plane Passing in Front of the Sun


Title: A Shot of a Plane Passing in Front of the Sun

This is a photo of an airplane crossing in front of the Sun. You can see the silhouette of the plane and jet wash in front of the Sun very clearly. This is the Sun observed using light known as the Hα line. The Sun was lively that day; you can see prominences, filaments, and plage on the surface of the Sun. We posted this image on the Twitter and we got more than 4,500 retweets (the number of citations)! It caught many people’s attention.

The Transit of a Plane Across the Sun

This picture was taken on February 28, 2015, using the Hα Full-disk Imager on the Solar Flare Telescope. Intense phenomena, such as solar flares and filament eruptions, sometimes occur on the Sun’s surface. They occasionally affect our Earth too. The Solar Flare Telescope monitors the Sun throughout the day so that it can capture these kinds of phenomena. We developed and installed software which can automatically detect when something extraordinary happens on the Sun’s surface. As a by-product of that, we sometimes capture the passing of a plane like this. The shadows of helicopters and birds are sometimes captured in the photographs. The composition of the image or the contrast between the background Hα-line solar disk and the silhouette of the jet wash and plane might be what caught many people’s attention on Twitter.

Text by: Kentaro Yaji (Solar Observatory, NAOJ)
Translation by: Hiroko Tsuzuki and Ramsey Lundock (NAOJ)

Image Data

ObjectThe Sun
TelescopeSolar Flare Telescope
InstrumentHα Full-disk Imager
Wavelengths656.3 nm
Exposure2.6 ms
DateFebruary 28, 2015
CreditNational Astronomical Observatory of Japan


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