NASA SOHO: Newfound Comet to Dive Through Sun

The Solar and Heliospheric Observatory captured this shot of a huge coronal mass ejection on Oct. 1, 2011, shortly after a comet dove into the sun (inset, right).

CREDIT: SOHO/NASA/ESA

A newly discovered comet is racing toward a mid-December rendezvous with the sun — a rendezvous that it will likely not survive.

The comet is categorized by astronomers as a "sungrazer" and it is destined to do just that; literally graze the surface of the sun (called the photosphere) and pass through the sun's intensely hot corona, where temperatures have been measured at upwards of 3.6-million degrees Fahrenheit (2-million degrees Celsius).

While the comet will not collide with the sun, most astronomers say the odds are rather long that it will remain intact after its closest pass by the sun. The most exciting aspect of the event is that the comet's expected destruction should be visible on your computer monitor.

And there is a very slight chance that, should the comet somehow manage to survive, it might briefly become visible in broad daylight.

Discovery
The comet was discovered by Australian amateur astronomer Terry Lovejoy Nov. 27 using a C8 Schmidt-Cassegrain telescope, working with a QHY9 CCD camera.

At first, Lovejoy believed that the rapidly moving fuzzy image he saw was nothing more than a camera reflection. But two nights later, despite clouds and haze, he managed to find the fuzzy object again and take several new images.

Lovejoy then put out a call to some trusted observers to confirm his observations. He received that confirmation Dec. 1 from Mount John Observatory, based in the Mackenzie Basin on the South Island of New Zealand. By then, 31 separate observations of the comet had been collected to determine an orbit, and the first announcement of Lovejoy's discovery was made this past Friday (Dec. 2) by the Minor Planet Center of the International Astronomical Union.

Its official title is C/2011 W3 (Lovejoy). It is Terry Lovejoy's third comet discovery.

NASA Soho: Small Comet dives into the Sun - Video

A small comet was witnessed by NASA's Solar and Heliospheric Observatory breaking down as it approached the Sun. The doomed sungrazer's last 4 hours (time-lapsed) were recorded on October 30.
Credit: NASA / SOHO

NASA STEREO, SOHO Spacecraft Catch Comet Diving Into Sun

Solar physicists at the University of California, Berkeley, have tracked a comet through the low solar atmosphere, deeper into the sun than ever before, before it presumably evaporated in the 100,000-degree heat.

Using instruments aboard NASA's twin STEREO spacecraft, four post-doctoral fellows at UC Berkeley's Space Sciences Laboratory were able to track the comet as it approached the sun and estimate an approximate time and place of impact.

STEREO (Solar TErrestrial RElations Observatory), launched in 2006, consists of identical spacecraft orbiting the sun, one ahead of Earth and one behind Earth, providing a stereo view of the sun.

The researchers then looked at data from the ground-based Mauna Loa Solar Observatory in Hawaii, and found images in the predicted spot of what appears to be a comet approaching the edge of the sun from behind the solar disk.

"We believe this is the first time a comet has been tracked in 3-D space this low down in the solar corona," said Claire Raftery, a post-doctoral fellow newly arrived at UC Berkeley from Dublin's Trinity College.

The team will present its data and images during a 5:30-6:30 p.m. poster session on Monday, May 24, at the Miami, Fla., meeting of the American Astronomical Society.

Sungrazing comets, composed of dust, rock and ice, are seldom tracked close to the sun because their brightness is overwhelmed by the solar disk. This comet apparently survived the heat of the corona and disappeared in the chromosphere, evaporating in the 100,000-degree (Kelvin) heat.

Raftery and her colleagues, Juan Carlos Martinez-Oliveros, Samuel Krucker and Pascal Saint-Hilaire, concluded that the comet was probably one of the Kreutz family of comets, a swarm of Trojan or Greek comets ejected from their orbit in 2004 by Jupiter, and that it made its first and only loop around the sun. The swarm probably resulted from the disintegration of a larger comet.