Incredibly, sungrazing Comet Lovejoy appears to have survived its close encounter with the sun. Lovejoy flew only 140,000 km over the stellar surface during the early hours of Dec. 16th. Experts expected the icy sundiver to be destroyed. Instead, NASA's Solar Dynamics Observatory caught the comet emerging from perihelion (closest approach) at least partially intact:
SDO also recorded Comet Lovejoy's entry into the sun's atmosphere: movie.
Comet Lovejoy began the week as a chunk of dusty, rocky ice some 200 meters in diameter. No one can say how much of the comet's core remains intact or how long it will hang together after the searing heat of perihelion.
New images received on Dec. 16th from the Solar and Heliospheric Observatory confirm that Comet Lovejoy survived perihelion and is now receding from the sun:
Curiously, the comet seems to have lost its tail in transit through the sun's hot corona. A decapitated remnant tail can still be seen tracing Comet Lovejoy's path into the sun, but the exiting comet has no obvious trail of dust behind it. One possibility has to do with geometry: The comet's tail might be pointing away from Earth, temporarily invisible due to foreshortening. Another possibility: The comet's store of volatile materials was "baked-out" by the fiery transit and now the comet is not jetting much dust and gas into space.
Discovered on Dec. 2nd by amateur astronomer Terry Lovejoy of Australia, the comet is an unusually large member of the Kreutz family. Kreutz sungrazers are fragments of a single giant comet (probably the Great Comet of 1106) that broke apart back in the 12th century. SOHO sees one plunging into the sun every few days, but most are small, no more than 10 meters wide. Comet Lovejoy is at least ten times larger than usual.
No comments