(See description below)
Transit of Venus
The transit or passage of a planet across the face of the Sun is a relatively rare occurrence. As seen from Earth, only transits of Mercury and Venus are possible. On average, there are 13 transits of Mercury each century. In contrast, transits of Venus occur in pairs with more than a century separating each pair. Before the 2004 transit, no living person had seen a transit of Venus because the previous one occurred in 1882.
Sunlight is refracted through the Venus atmosphere. In the image, this is visible against the dark background outside the solar disk. (The bright ring is artificially enhanced nine times here.)
The image was recorded using the 1-meter Swedish Solar Telescope located on La Palma in the Canary Islands. For the Institute for Solar Physics, Dan Kiselman, Goran Scharmer, Kai Langhans, and Peter Dettori were at the telescope, while Mats Lofdahl produced the final image.