Watch as Comet Lovejoy Takes a Death-Dive Into the Sun

A comet discovered on Dec. 2, 2011 is now on a near collision course with the Sun, and likely won’t survive such a close encounter. The best part is that you can follow along and watch as it happens! Comet C/2011 W3 Lovejoy will pass behind the sun at around 24:00 UTC (7 pm EST) on Thursday, Dec. 15, 2011 and probably won’t be seen again. In the video above, processed images from the STEREO A spacecraft shows Comet Lovejoy blazing towards the Sun, with the comet’s tail wiggling as it interacts with the solar wind.

The Solar Dynamics Observatory website has a special page where they will be uploading the latest images of the comet as it meets its fiery fate. As Comet Lovejoy moves toward perihelion, the SDO team will point SDO a little to the left of the Sun to try and see the tail of the comet with their instruments. This website will allow you to see those images as quickly as they can download them from the spacecraft.

Science live and in action!

Astronomers and various spacecraft have been keeping an eye on Comet Lovejoy the past few days as this Kreutz-group comet headed towards the Sun. Just today (Thursday) the images from the SOHO spacecraft showed the comet sprouting a bulbous head. This is occurring because the comet is getting so bright, it is overwhelming the detectors on the SOHO satellite. “The photons are ‘bleeding’ out to form that cross-like pattern,” said Dan Pendick on the Geeked On Goddard website.

Pendick also quoted solar scientist Jack Ireland from Goddard, who noted that at times two tails can be seen on the comet. “The thick white tail is primarily dust breaking away from the comet nucleus,” Ireland said, as the Sun’s radiation and solar wind that knocks material off the comet nucleus. But to the left is a tail of charged particles (ions) being deflected to the side by the magnetic field carried by the solar wind.

At its closest approach, Comet Lovejoy will pass just 120,000 km above the solar surface. At that distance, the icy comet is not expected to survive the Sun’s fierce heat. But the comet could actually disintegrate at any moment. Kreutz comets have a tendency to evaporate as they approach, or pass close to the Sun.

If the comet does stay the course and stay visible until it goes around the Sun, we likely won’t be able to see its demise because its closest approach will take place on the far side of the Sun.

But this is a great chance to watch this event as it is about to happen.

“We have here an exceptionally rare opportunity to observe the complete vaporization of a relatively large comet, and we have approximately 18 instruments on five different satellites that are trying to do just that,” wrote Karl Battams, from the Naval Research Laboratory, who curates the Sun-grazing comets webpage, and has been documenting Lovejoy’s journey.

Amateur astronomers have been trying to capture this event as well, with everyone wondering how bright the comet will get. For updates from amateur astronomers, check out the Yahoo Groups comet observers forum.

Comet C/2011 W3 Lovejoy was actually discovered by an amateur, Australian astronomer Terry Lovejoy (hence the comet’s name.) This is the first Kreutz comet found from a ground-based observer since 1970, and it was spotted with a modest 8″ telescope too! You can read Lovejoy’s tale of his discovery here.

On average, new Kreutz-group comets are discovered every few days by spacecraft like SOHO, but from the ground they are much rarer to see and harder to discover.

“This is the first ground-based discovery of a Kreutz-group comet in 40 years, so we really can’t be sure just how bright it will get,” said Battams. “However, I do think that it will be the brightest Kreutz-group comet SOHO has ever seen.”

Comet Lovejoy’s spectacular progress can also be monitored via the web at SOHO’s LASCO instrument page.

For the SDO special webpage, images from SDO take about 30 minutes to move from the spacecraft until they are available on the website. The SOD team plans to off-point the spacecraft at 23:30 UTC (6:30 pm ET) and return to normal solar observing at 12/16 00:30 UTC (7:30 pm ET). Images should start arriving by 24:00 UTC (7 pm EST.)

Did a Comet Hit Cause an Explosion on the Sun?

This amazing video from the SOHO mission (Solar and Heliospheric Observatory) shows a sun-diving comet hitting the solar surface on October 1, 2011 and unexpectedly a huge explosion occurs shortly after. Are the two events related? Probably not, but solar scientists don’t know for sure. The region where the CME originated was on the opposite side of the Sun from the comet hit, so that is very great distance. Scientists say there is no known mechanism for comets to trigger a CME.

SpaceWeather.com reports that before 2011 most solar physicists would have discounted these two events as being related, but earlier this year, the Solar Dynamics Observatory (SDO) watched another sungrazer comet disintegrate in the Sun’s atmosphere, and it appeared to interact with plasma and magnetic fields in its surroundings as it fell apart. Could a puny comet cause a magnetic instability that might propagate and blossom into a impressive CME? Most likely this is just a coincidence, but this is definitely an event in which solar scientists are taking a closer look. The comet, named SOHO-2143, was just discovered on Sept. 30 by an amateur astronomer.

See below for SDO’s look at two solar flares which also occurred on October 1, showing how events on the Sun can be related.
Continue reading “Did a Comet Hit Cause an Explosion on the Sun?”

Scientists Detect Sunspots Before They Emerge

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For solar enthusiasts, we’re all quite aware of sunspots and their implications. Able to disrupt power grids, shut down satellite communications and pose hazards to astronauts, these “cool” customers are revealing themselves ahead of their surface appearance. Thanks to the Michelson Doppler Imager aboard NASA’s Solar and Heliospheric Observatory satellite, known as SOHO, researchers were able to take 15 years of “sound” data from our nearest star… and develop a new technique for detecting sunspots before they emerge.

By combining information with NASA’s Solar Dynamics Observatory satellite, which carries the Helioseismic and Magnetic Imager, scientists have discovered a new method for detecting sunspots as deep as 65,000 kilometers below the solar surface. The areas of intense magnetic fields produce acoustic waves from the turbulence of plasma and gases. Near the surface, a convection cell echoes the information which travels back to the solar interior – only to be refracted again. By comparing their findings to seismic waves studied here on Earth, researchers measure the waves between points to predict anomalies.

Detection of Emerging Sunspot Regions – 18 August 2011: Movie showing the detected travel-time perturbations before the emergence of active region 10488 in the photosphere. The first 10 seconds of the movie show intensity observations of the Sun. The intensity later fades out and the photospheric magnetic field is shown. In the next 20 seconds, we zoom in to a region where a sunspot group would emerge. The upper layer shows magnetic field observations at the surface and the lower layer shows simultaneous travel-time perturbations, detected at a depth of about 60,000 km. After the emergence, intensity observations show the full development of this active region, until it rotates out of view on the west solar limb. (movie made by Thomas Hartlep) Courtesy of the Helioseismic and Magnetic Imager.

“We know enough about the structure of the Sun that we can predict the travel path and travel time of an acoustic wave as it propagates through the interior of the Sun,” said Junwei Zhao, a senior research scientist at Stanford’s Hansen Experimental Physics Lab. “Travel times get perturbed if there are magnetic fields located along the wave’s travel path.”

By comparing and measuring millions of pairs and points, researchers are able to pinpoint areas where sunspots are likely to happen. What they have discovered is larger spots rise to the surface faster than smaller ones… a prediction which can be made in approximately 24 hours. For less ominous appearances, lead times increase to up to two days.

“Researchers have suspected for a long time that sunspot regions are generated in the deep solar interior, but until now the emergence of these regions through the convection zone to the surface had gone undetected,” Ilonidis said. “We have now successfully detected them four times and tracked them moving upward at speeds between 1,000 and 2,000 kilometers per hour.”

The ultimate goal is to improve space weather forecasting. If events can be predicted three days prior, advance notice can be given and proper precautions taken.

Original Story Source: Stanford University News.

Sun Celebrates Solstice With Flare (and a CME)

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Late in the evening on June 20, 2011 the Sun emitted a long lasting C7.7 class flare (a relatively small flare) that peaked around 11:25p.m. EDT. The flare was associated with a coronal mass ejection that bloomed off the sun at 11:09p.m. EDT (0412 UT).

Spaceweather.com reports that according to analysts at the Goddard Space Flight Center Space Weather Lab, the CME left the sun traveling 800 km/s and it will reach Earth on June 23rd at 23:22 UT (plus or minus 7 hours). A very cool 3D heliospheric model (below) shows the cloud sweeping past our planet. The impact is expected to trigger a G2-class geomagnetic storm.

High-latitude sky watchers should be alert for auroras on June 23rd and 24. The season favors southern hemisphere observers, where skies are darker for longer due to the winter solstice.

These 3D Heliospheric animated models, developed by the Community Coordinated Modeling Center based at the Goddard Space Flight Center, show how the CME cloud might appear as it sweeps past Earth. Credit: NASA/CCMC

Update: SDO posted this video of the event:

Sources: NASA, Spaceweather.com

More Eye-Popping Video from the June 7 Solar Explosion

Massive coronal mass ejection on. This image shows the size of the Earth to scale. NASA / SDO / J. Major.

Here’s more video from the huge explosion on the Sun on June 7, 2011, which began at about 06:41 UTC. Not only was this event one of the most spectacular ever recorded, but also one of the best observed, with complementary data from several spacecraft and different vantage points. This video shows data from three different space observatories. The Solar Dynamics Observatory’s Atmospheric Imaging Assembly recorded the amazing event in stunning detail in different wavelengths. Additionally, the Solar & Heliospheric Observatory’s (SOHO) LASCO coronagraph and STEREO’s (Solar Terrestrial Relations Observatory) SECCHI instrument suite observed the prominence and associated CME as they traveled out into the heliosphere. Using LASCO and SECCHI data, the speed of the leading edge of the CME was estimated to be in the range 1200 – 1600 km/s. Model calculations predict that Earth will receive a glancing blow of the CME on June 10, possibly sparking some nice aurorae at high latitudes, according to the SDO team.

The citizen science project Solar Storm Watch predicts a solar storm to reach Earth at 08:00 UTC on June 10, 2011 with a glancing blow 35 degrees behind Earth, with a second storm expected at 19:00 UTC on June 10, 2011, with another glancing blow 32 degrees behind Earth.

The event originated from the almost spotless active region 11226 and was associated with a moderate M2-class X-ray flare. The CME and associated shock wave produced and S1-class radiation storm, which shows up as speckles in the LASCO movies.

The size of the prominence is thought to be at least 75 times the size of Earth. Our Jason Major created a graphic showing the size comparison. Earth is the little teeny tiny blue circle in the top left corner:

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Just How Active is our Sun Now Compared to Two Years Ago?

This video provided by the Solar Dynamics Observatory provides a side-by-side comparison of the Sun from precisely two years ago (left, from SOHO in 2009) to the present (right, from Solar Dynamics Observatory, showing March 27-28, 2011) which dramatically illustrates just how active the Sun has become. The comparisons shown in two similar wavelengths of extreme ultraviolet light, reveal how the Sun now sports numerous active regions that appear as lighter areas that are capable of producing solar storms. Two years ago the Sun was in an extremely quiet solar minimum. The Sun’s maximum period of activity is predicted to be around 2013, so activity will likely continue to ramp up.

Double Explosions on the Sun Today

The Sun had a fit and popped off two large events at once early today, Jan. 28, 2011. A filament on the left side became unstable and erupted, while an M-1 flare (mid-sized) and a coronal mass ejection on the right blasted into space. Neither event was headed towards Earth. This SDO movie, which is from Jan. 26-28, 2011, shows several other flashes and bursting from the active region on the right as well.

If you remember, in December, solar physicists released their findings that near-synchronous explosions in the solar atmosphere – sometimes millions of kilometers apart – can be related.

You can see another view of the events as seen by the SOHO spacecraft below, and another version of the SDO data.
Continue reading “Double Explosions on the Sun Today”

SOHO Finds Its 2000th Comet

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From a NASA Press Release:

As people on Earth celebrate the holidays and prepare to ring in the New Year, an ESA/NASA spacecraft has quietly reached its own milestone: on December 26, the Solar and Heliospheric Observatory (SOHO) discovered its 2000th comet.

Drawing on help from citizen scientists around the world, SOHO has become the single greatest comet finder of all time. This is all the more impressive since SOHO was not specifically designed to find comets, but to monitor the sun.

“Since it launched on December 2, 1995 to observe the sun, SOHO has more than doubled the number of comets for which orbits have been determined over the last three hundred years,” says Joe Gurman, the U.S. project scientist for SOHO at NASA’s Goddard Space Flight Center in Greenbelt, Md.

Of course, it is not SOHO itself that discovers the comets — that is the province of the dozens of amateur astronomer volunteers who daily pore over the fuzzy lights dancing across the pictures produced by SOHO’s LASCO (or Large Angle and Spectrometric Coronagraph) cameras. Over 70 people representing 18 different countries have helped spot comets over the last 15 years by searching through the publicly available SOHO images online.

The 1999th and 2000th comet were both discovered on December 26 by Michal Kusiak, an astronomy student at Jagiellonian University in Krakow, Poland. Kusiak found his first SOHO comet in November 2007 and has since found more than 100.

“There are a lot of people who do it,” says Karl Battams who has been in charge of running the SOHO comet-sighting website since 2003 for the Naval Research Lab in Washington, where he also does computer processing for LASCO. “They do it for free, they’re extremely thorough, and if it wasn’t for these people, most of this stuff would never see the light of day.”

Battams receives reports from people who think that one of the spots in SOHO’s LASCO images looks to be the correct size and brightness and headed for the sun – characteristics typical of the comets SOHO finds. He confirms the finding, gives each comet an unofficial number, and then sends the information off to the Minor Planet Center in Cambridge, Mass, which categorizes small astronomical bodies and their orbits.

It took SOHO ten years to spot its first thousand comets, but only five more to find the next thousand. That’s due partly to increased participation from comet hunters and work done to optimize the images for comet-sighting, but also due to an unexplained systematic increase in the number of comets around the sun. Indeed, December alone has seen an unprecedented 37 new comets spotted so far, a number high enough to qualify as a “comet storm.”

LASCO was not designed primarily to spot comets. The LASCO camera blocks out the brightest part of the sun in order to better watch emissions in the sun’s much fainter outer atmosphere, or corona. LASCO’s comet finding skills are a natural side effect — with the sun blocked, it’s also much easier to see dimmer objects such as comets.

“But there is definitely a lot of science that comes with these comets,” says Battams. “First, now we know there are far more comets in the inner solar system than we were previously aware of, and that can tell us a lot about where such things come from and how they’re formed originally and break up. We can tell that a lot of these comets all have a common origin.” Indeed, says Battams, a full 85% of the comets discovered with LASCO are thought to come from a single group known as the Kreutz family, believed to be the remnants of a single large comet that broke up several hundred years ago.

The Kreutz family comets are “sungrazers” – bodies whose orbits approach so near the Sun that most are vaporized within hours of discovery – but many of the other LASCO comets boomerang around the sun and return periodically. One frequent visitor is comet 96P Machholz. Orbiting the sun approximately every six years, this comet has now been seen by SOHO three times.

SOHO is a cooperative project between the European Space Agency (ESA) and NASA. The spacecraft was built in Europe for ESA and equipped with instruments by teams of scientists in Europe and the USA.

For more information see the SOHO website. .

See SOHO realtime data.

SoHO Celebrates its 12th Birthday

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On December 2nd, 1995 a large joint ESA and NASA mission was launched to gain an insight to the dynamics of the Sun and its relationship with the space between the planets. 12 years on, the Solar and Heliospheric Observatory (SoHO) continues to witness some of the largest explosions ever seen in the solar system, observes beautiful magnetic coronal arcs reach out into space and tracks comets as they fall to a fiery death. In the line of duty, SoHO even suffered a near-fatal shutdown (in 1998). As far as astronomy goes, this is a tough assignment.

By the end of 1996, SoHO had arrived at the First Lagrange Point between the Earth and the Sun (a gravitationally stable position balanced by the masses of the Sun and Earth, about 1.5 million km away) and orbits this silent outpost to this day. It began to transmit data at “solar minimum”, a period of time at the beginning of the Solar Cycle, where sunspots are few and solar activity is low, and continues toward the upcoming solar minimum after the exciting firworks of the last “solar maximum”. This gives physicists another chance to observe the majority of a Solar Cycle with a single observatory (the previous long-lasting mission was the Japanese Yohkoh satellite from 1991-2001).

On board this ambitious observatory, 11 instruments constantly gaze at the Sun, observing everything from solar oscillations (“Sun Quakes�), coronal loops, flares, CMEs and the solar wind; just about everything the Sun does. SoHO has become an indispensable mission for helping us to understand how the Sun influences the environment around our planet and how this generates the potentially dangerous “Space Weather�.

The SoHO mission site confidently states that SoHO will remain in operation far into the next Solar Cycle. I hope this is the case as the new Hinode and STEREO probes will be good company for this historic mission.

Source: NASA News Release