NASA | SDO Sees Comet Lovejoy Survive Close Encounter with Sun
One instrument watching for the comet was the Solar Dynamics Observatory (SDO), which adjusted its cameras in order to watch the trajectory. Not only does this help with comet research, but it also helps orient instruments on SDO -- since the scientists know where the comet is based on other spacecraft, they can finely determine the position of SDO's mirrors. This first clip from SDO from the evening of Dec 15, 2011 shows Comet Lovejoy moving in toward the sun.
Comet Lovejoy survived its encounter with the sun. The second clip shows the comet exiting from behind the right side of the sun, after an hour of travel through its closest approach to the sun. By tracking how the comet interacts with the sun's atmosphere, the corona, and how material from the tail moves along the sun's magnetic field lines, solar scientists hope to learn more about the corona. This movie was filmed by the Solar Dynamics Observatory in 171 Angstrom wavelength, which is typically shown in yellow.
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
Comet Lovejoy just missed being consumed by the Sun. Its original trajectory took it just fraction of a solar radius from our Sun emerging on the other side. Here are a few Images from the Solar and Heliospheric Observatory (SOHO) from yesterdays occurrance: http://www.pcmag.com/article2/0,2817,2397756,00.asp
My questions are what was the initial trajectory, final trajectory and Perihelion (closest distance from the Sun) so I may make a model of the hyperbolic or parabolic path the Comet is on.
Philosophaie wrote:My questions are what was the initial trajectory, final trajectory and Perihelion (closest distance from the Sun) so I may make a model of the hyperbolic or parabolic path the Comet is on.
You can find the orbital elements here. I don't know how much the encounter altered the orbit; I expect that new elements will be posted within a few days, once more observations are recorded.
Chris
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Chris L Peterson
Cloudbait Observatory https://www.cloudbait.com
Philosophaie wrote:My questions are what was the initial trajectory, final trajectory and Perihelion (closest distance from the Sun) so I may make a model of the hyperbolic or parabolic path the Comet is on.
You can find the orbital elements here. I don't know how much the encounter altered the orbit; I expect that new elements will be posted within a few days, once more observations are recorded.
I clicked on the link, Chris, not really expecting that i would find anything that i would understand, and i was not disappointed, until i got to the date of the last set of numbers. The date is--->2012 01 01. So i figure that they had enough information to 'plot ahead' that far, as it is still 2011. If indeed that is the case....then i actually did understand something on that page
It was almost a pre-holiday miracle that Comet Lovejoy survived its close encounter with the Sun on Dec. 15, 2011. But now, the feisty comet is making a ‘merry and bright’ comeback, re-sprouting its tail and showing up brilliantly with binoculars and in telescopic images from southern hemisphere skywatchers.
“It was a big surprise that after going through the solar atmosphere it re-emerged with a beautiful tail,” Karl Battams told Universe Today. Battams is with Naval Research Laboratory and has been detailing the Comet Lovejoy’s incredible journey on the Sungrazing Comets website. “And basically within a day it was as bright after the encounter as it was before.”
The beautiful image above was taken on Dec. 17, 2011, clearly showing two gorgeous tails on Comet Lovejoy. See more from the Czech team that took the image at their website, Kommet.cz.
As much as this comet has surprised everyone, no one is going out on a limb and predicting it will become visible with the naked eye. But who knows? The comet’s discoverer, Austrailian amateur astronomer Terry Lovejoy was able to image the comet in the day time! ” I am hopeful of a nice binocular comet low in the dawn around Christmas time,” Lovejoy said on the Ice in Space website.
“Southern hemisphere viewers can see it now early in the morning,” Battams said via phone this morning. “It is going to become increasingly easy for them to see as it moves away from the Sun. I’m not sure it will increase in brightness anymore, as it has leveled off a little bit now. Odds are stacked in the favor of a nice nighttime show for southern viewers, and gradually it will fade away.”
Of course, Comet Lovejoy isn’t the only comet that has survived a close encounter with the Sun; in fact, some comets have even brightened to naked eye visibility after surviving a scorching from the Sun. The “Great Comets” of 1843 and 1882, and Comet Ikeya-Seki of 1965 were all Kreutz sungrazers – like Comet Lovejoy — and they all became brilliant after their solar encounters, with extraordinarily long tails.
Normally these comets don’t survive and are completely obliterated by the Sun. But the few that do – only 2 or 3 a century — can be very bright.
I had asked Battams on Friday – just after the comet emerged from behind the Sun – his thoughts on Comet Lovejoy and if it might follow the example of those previous surviving sungrazers.
“All bets are off as far as I’m concerned,” he wrote via email. “We thought this was a relatively small one — maybe a hundred or two meters in diameter. Clearly it can’t be. I did not expect it to survive perihelion as anything more than a diffuse blob that would rapidly dissipate. Instead it is pretty much as bright as it was before, just with less of a tail now.”
So keep a lookout for the holiday comet of 2011, the merry and bright Comet Lovejoy!
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
We can’t get enough of Comet Lovejoy! But this latest image is off the charts for its beauty and it’s jaw-dropping to contemplate it was taken from space. Dan Burbank, Expedition 30 commander onboard the International Space Station took this image of Comet Lovejoy on Dec. 21, 2011. See more of Burbank’s shots of Lovejoy here.
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
The recently discovered Comet Lovejoy has been captured in stunning photos and time-lapse video taken from ESO’s Paranal Observatory in Chile. The comet graced the southern sky after it had unexpectedly survived a close encounter with the Sun.
A new time-lapse video sequence was taken by Gabriel Brammer from ESO less than two days ago on 22 December 2011. Gabriel was finishing his shift as support astronomer at the Paranal Observatory when Comet Lovejoy rose over the horizon just before dawn.
In the words of Gabriel Brammer himself: “On the last morning of my shift I tried to try catch it on camera before sunrise. The tail of the comet was easily visible with the naked eye, and the combination of the crescent Moon, comet, Milky Way and the laser guide star was nearly as impressive to the naked eye as it appears in the long-exposure photos.”
The sequence also features the pencil-thin beam of the VLT’s Laser Guide Star set against the beautiful backdrop of the Milky Way, as astronomers conduct their last observations for the night.
ESO optician Guillaume Blanchard made a marvellous wide-angle photo of Comet Lovejoy and ESO Photo Ambassador Yuri Beletsky, captured the spectacle from Santiago de Chile. Blanchard said: "For me this comet is a Christmas present to the people who will stay at Paranal over Christmas".
This bright comet was also seen from the International Space Station in another stunning time-lapse sequence on 21 December as the crew filmed lightning on the Earth’s night side.
Comet Lovejoy has been the talk of the astronomy community over the past few weeks. It was discovered on 27 November by the Australian amateur astronomer Terry Lovejoy and was classified as a Kreutz sungrazer, with its orbit taking it very close to the Sun [1]. Just last week, the comet entered the Sun’s corona, a much-anticipated event, passing a mere 140 000 kilometres from the Sun’s surface. A close shave indeed...
The comet was expected to break up and vaporise, but instead it survived its steaming hot encounter with the Sun and re-emerged a few days later, much to everyone's surprise. It is now visible from the southern hemisphere, appearing at dawn, and features a bright tail millions of kilometres long, composed of dust particles that are being blown ahead of the comet by the solar wind.
Lovejoy will now continue in its highly eccentric orbit around the Sun and once again disappear into the distant Solar System. It would be interesting to know if it will actually survive to re-appear in our skies in 314 years as predicted.
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
Comets are icy and fragile. They spend most of their time orbiting through the dark outskirts of the solar system safe from destructive rays of intense sunlight. The deepest cold is their natural habitat.
Last November amateur astronomer Terry Lovejoy discovered a different kind of comet. The icy fuzzball he spotted in the sky over his backyard observatory in Australia was heading almost directly for the sun. On Dec. 16th, less than three weeks after he found it, Comet Lovejoy would swoop through the sun’s atmosphere only 120,000 km above the stellar surface.
Astronomers soon realized a startling fact: Comet Lovejoy likes it hot.
"Terry found a sungrazer," says Karl Battams of the Naval Research Lab in Washington DC. "We figured its nucleus was about as wide as two football fields—the biggest such comet in nearly 40 years.”
Sungrazing comets aren't a new thing. In fact, the orbiting Solar and Heliospheric Observatory (SOHO) watches one fall toward the sun and evaporate every few days. These frequent kamikaze comets, known as “Kreutz sungrazers,” are thought to be splinters of a giant comet that broke apart hundreds of years ago. Typically they measure about 10 meters across, small, fragile, and easily vaporized by solar heat.
Based on its orbit, Comet Lovejoy was surely a member of the same family—except it was 200 meters wide instead of the usual 10. Astronomers were eager to see such a whopper disintegrate. Even with its extra girth, there was little doubt that it would be destroyed.
When Dec. 16th came, however, "Comet Lovejoy shocked us all," says Battams. "It survived, and even flourished.”
Images from NASA's Solar Dynamics Observatory showed the comet vaporizing furiously as it entered the sun's atmosphere--apparently on the verge of obliteration—yet Comet Lovejoy was still intact when it emerged on the other side. The comet had lost its tail during the fiery transit--a temporary setback. Within hours, the tail grew back, bigger and brighter than before.
"It's fair to say we were dumbfounded," says Matthew Knight of the Lowell Observatory and the Johns Hopkins Applied Physics Lab. "Comet Lovejoy must have been bigger than we thought, perhaps as much as 500 meters wide."
That would make it the biggest sungrazer since Comet Ikeya-Seka almost 40 years ago. With a tail that stretched halfway across the sky, Ikeya-Seki was actually visible in broad daylight after it passed through the sun's atmosphere in October 1965. In Japan, where observers spotted the over-heated comet only 1/2 degree from the sun, it was described as 10 times brighter than the Full Moon.
Comet Lovejoy wasn't that bright, but it was still amazing. Only a few days after it left the sun, the comet showed up in the morning skies of the southern hemisphere. Observers in Australia, South America, South Africa, and New Zealand likened it to a search light beaming up from the east before dawn. The tail lined up parallel to the Milky Way and, for a few days, made it seem that we lived in a double-decker galaxy.
This sequence of images, gathered by an extreme UV telescope
onboard NASA's STEREO-B spacecraft, shows Comet Lovejoy's
tail wiggling wildly in transit through the solar corona.
Astronauts on the International Space Station also witnessed the comet. ISS Commander Dan Burbank, who has seen his share of wonders, even once flying directly through the Northern Lights onboard the space shuttle, declared Comet Lovejoy “the most amazing thing I have ever seen in space.”
An armada of spacecraft including SOHO, the Solar Dynamics Observatory, NASA's twin STEREO probes, Japan’s Hinode spacecraft, and Europe's Proba2 microsatellite recorded the historic event.
"We've collected a mountain of data," says Knight. "But there are some things we're still having trouble explaining."
For instance, what made Lovejoy's tail wiggle so wildly when it entered the solar corona? Perhaps it was in the grip of the sun's powerful magnetic field.
What caused Lovejoy to lose its tail inside the sun's atmosphere—and then regain it later? “This is one of the biggest mysteries to me,” says Battams.
And then there is the ultimate existential puzzle: How did Comet Lovejoy survive at all?
As January unfolds, the “Comet that liked it Hot” is returning to the outer solar system, still intact, leaving many mysteries behind. “It’ll be back in about 600 years,” says Knight. “Maybe we will have figured them out by then.”
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
Object: Particularly hardy sungrazer comet
Origins: Long lineage of sun-divers
Click to play embedded YouTube video.
After passing through the edge of the sun, Lovejoy the warrior was hailed as the great survivor. Amid warnings that such a perilous quest would almost certainly be fatal, Lovejoy dived into the sun's flaming corona and, to everyone's surprise, emerged on the other side, battered but not broken. Fellow warriors had come charging at the fiery beast before but almost all were consumed. The world rejoiced as the hero's bright banner outshone every star in the sky.
That, at least, is how it appeared back in December 2011, when that feat of derring-do occurred. Now it seems that Lovejoy – a comet – was not as hardy as we thought. A new analysis finds that the comet lost its head and disintegrated two days after its impressive feat, thanks to a hidden build-up of thermal stress.
Thankfully, the tale isn't without hope. Zdenek Sekanina and Paul Chodas, of NASA's Jet Propulsion Laboratory in California, who carried out the new study, also suggest that Lovejoy was the first of a whole cluster of bright comets that should approach the sun in the 2040s.
Lovejoy, more technically known as comet C/2011 W3, was first spotted by its namesake – Australian amateur astronomer Terry Lovejoy – a few weeks before it ploughed into the sun's corona. Scientists calculated its orbital path, which revealed that the comet would reach perihelion, its closest approach to the sun, in mid-December.
Vanishing head
The comet was part of the Kreutz family of sungrazers. Orbiting telescopes such as NASA's Solar and Heliospheric Observatory had witnessed the demise of hundreds of sungrazers before, and all expectations were that Lovejoy would also perish.
On 16 December, a host of space-based telescopes and ground-based enthusiasts watched as Lovejoy flew into the solar corona, where temperatures reach 1 million Kelvin. Amazingly, the object reappeared after almost an hour. In the coming days, sky-watchers in the southern hemisphere saw the comet and its bright tail near the pre-dawn horizon as it retreated from the sun.
Lovejoy was hailed as an incredible find by professional and hobbyist astronomers alike. And it was. But the story is not as simple as it seems.
Sekanina and Chodas have reanalysed pictures taken on 20 December, showing that Lovejoy's nucleus, the cometary equivalent of a head, had suddenly vanished. The headless tail boasted only a long, bright "spine", which Sekanina and Chodas now think was the denser dust of the broken nucleus.
Dry body
Using data on the likely structure and composition of comets from past missions, the team assumed that Lovejoy's nucleus was a roughly spherical, rocky conglomeration of consolidated dust, covered with a layer of water ice. They then used near-infrared studies of heat emissions from other comets to calculate the rate at which heat would move through Lovejoy's nucleus.
According to the researchers, the comet's trek into the corona rapidly vaporised all its surface ice, leaving only the dusty core. Shortly after the ordeal, this dry body started to crack and flake away in the extreme heat. "Very close to perihelion, already 10 metres or more of the comet has completely disintegrated," says Sekanina.
Lovejoy was just the right size to survive the dive itself. Starting at around 500 metres wide, the comet emerged at less than 200 metres across.
But Sekanina and Chodas now show that even once it was moving away from the sun, heat continued to penetrate deeper into the comet. "The surface of the comet as it recedes gets cooler, but the interior still gets warmer, because to transfer heat takes time," says Sekanina.
Crumpled core
That was enough to seal its fate, the pair conclude. When enough thermal stress had built up in its core, the comet crumpled – which in some ways vindicates those who said it would be destroyed. "The guys who said the comet won't survive perihelion were off by 1.6 days," says Sekanina.
But Sekanina and Chodas were also interested in the famous comet's origins, and what this might say about future sungrazers. Kreutz sungrazers all follow the same orbit, so are thought to be pieces of a larger comet that broke apart millennia ago. These fragments then repeatedly broke up, spawning further children and grandchildren.
By combining pictures of the retreating tail with images of Lovejoy's approach, the pair traced the comet's orbital period, the time it takes to complete a turn around the sun. Their calculations suggest that Lovejoy has an orbital period of about 698 years.
Sun-grazing flurry
There's no perfect match for a sungrazing comet appearing 698 years ago in historical accounts, but the team estimates that Lovejoy was most likely born from a Kreutz descendant that neared the sun in the 14th century and then spilt into further fragments, a cluster of which may visit the sun in a few decades.
Similar bright clusters were seen in the 1880s and 1960s. Due to gravitational perturbations with the planets, some comets in these clusters are known to alter course and appear roughly 20 to 30 years ahead of the pack. Sekanina and Chodas calculate that Lovejoy fits the profile of such a front runner, which means we should be in for another flurry of sungrazers in the 2040s.
"We have concluded that the 1960s is not the end of the whole show. There will be another cluster coming," says Sekanina.
Will one of these be as hardy as Lovejoy and survive a plunge through the sun's corona? Who knows. Perhaps one will emerge that is even tougher and will live long after its visit.
Comet C/2011 W3 (Lovejoy): Orbit Determination, Outbursts, Disintegration of Nucleus, Dust-Tail Morphology,
and Relationship to New Cluster of Bright Sungrazers - Zdenek Sekanina, Paul W. Chodas
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
