Comet Lovejoy blazes through sun’s corona
Something amazing happened tonight: a tiny comet skimmed just above the surface of the sun. Yeah, this happens pretty regularly, as we noted awhile back, but this one was special: an amateur astronomer Terry Lovejoy of Australia spotted the inbound comet about 2 weeks ago, giving astronomers worldwide plenty of time to train their sites on it as it blew ’round the sun. No one knew if it would survive its closest approach, which occurred at about sunset here in New Mexico.
SOHO, the space-based solar observatory, caught this sequence of its approach (the video covers almost 4 days):
While the brightness might make you think this is a giant comet, what you’re seeing is a cometary glow that blows out the sensitive CCD sensors, which are meant to help resolve the subtle, faint structures in the sun’s corona (which you can see dancing around in the images). The actual sun diameter is the inner circle; the outer circle blocks the brightest corona so the cameras can watch the outer corona. This comet was about 200m in diameter; while it’s the largest of over 2000 sun-grazing comets seen since SOHO launched in 1996, this is still puny by cometary standards – the small but very close Hyakutake was about 2km (2000m) in diameter, Halley’s is about 15km, and Hale-Bopp about 40km. Still, late this afternoon, the comet was brighter than the brightest stars or planets, though too close to the sun to be seen with the naked eye.
And tonight, this amazing video came in from the Solar Dynamics Observatory, showing the comet apparently surviving perihelion, whizzing through the solar corona. It passed only 140,000km above the sun’s surface: that’s just ten or so earth-diameter! Yoswa. (the video loops three times, each time in slower motion)
I tell ya, we’ve got some pretty darn amazing eyes on the skies these days! (Here’s another view of the closest passage, offering a wider perspective, and here’s the SOHO view from the next morning, showing the tail left behind as the comet emerges and heads back out away from its hairy close encounter with our star.)
For more images and a complete run-down on the approach and passage of Comet Lovejoy, check out AstroBob’s day-of coverage and his posts in the few days before and after.
UPDATE, 12/22/11: Not only did our little hero survive, but it’s putting on a nice, though subtle, morning show in the southern hemisphere. The tail is 15 degrees long, about half of which is visible to the naked eye just before sunrise; as always, cameras bring out the detail with slightly longer exposure times. Here’s one from Colin Legg of Mandurah, Western Australia, recently posted on SpaceWeather.com: