Sungrazer
A sungrazer is a comet that passes extremely close to the Sun, often skimming through its outer atmosphere.
A sungrazing comet comes very close to the Sun at perihelion, sometimes within a few hundred thousand kilometres of its visible surface. Most sungrazers belong to the Kreutz family, fragments of a large comet that broke up perhaps more than two thousand years ago.
The Solar and Heliospheric Observatory, SOHO, launched in 1995 to watch the Sun, has discovered more than 5,000 comets, most of them small Kreutz sungrazers that vaporise as they approach the Sun. Many were found by amateur astronomers looking through its publicly released images. Larger sungrazers, such as the Great Comet of 1882 and Comet Lovejoy in 2011, can survive and become dazzling sights.
Sungrazers show how comets fragment repeatedly and how dust and gas are released under extreme heating. Studying them also helps solar physicists, because they act as probes of the Sun's magnetic field and outer atmosphere, the corona.
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Level: Expert Advanced