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An interesting coronal mass ejection (CME) blasted into space on March 5, 2007 as observed by the LASCO C2 instrument. The CME was not particularly large, but its core held its central shape together like a static object. As the bulbous front end of the CME emerged from behind the occulting disk, it carved out a dark area, which we usually see as a brighter edge. Then as the darker mass moved away from the Sun, the second half of the teardrop-shaped cloud appeared as whiter, suggesting a greater intensity of material. As the cloud moved across the field of view and out of sight, its shape, instead of broadening and expanding, seemed to hold itself together quite well in a fairly tight cocoon-looking shape. Other solar material burst out above and below this central pattern as is commonly seen. While the character of this event is not entirely unique, we have only seen this kind of behavior a few times in our 11 years of observations.
An interesting coronal ...
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Description An interesting coronal mass ejection (CME) blasted into space on March 5, 2007 as observed by the LASCO C2 instrument. The CME was not particularly large, but its core held its central shape together like a static object. As the bulbous front end of the CME emerged from behind the occulting disk, it carved out a dark area, which we usually see as a brighter edge. Then as the darker mass moved away from the Sun, the second half of the teardrop-shaped cloud appeared as whiter, suggesting a greater intensity of material. As the cloud moved across the field of view and out of sight, its shape, instead of broadening and expanding, seemed to hold itself together quite well in a fairly tight cocoon-looking shape. Other solar material burst out above and below this central pattern as is commonly seen. While the character of this event is not entirely unique, we have only seen this kind of behavior a few times in our 11 years of observations.
The STEREO (behind) spacecraft observed this small prominence rising up from the Sun's surface, twisting around, and subsiding over about a 36-hour period (Oct. 31- Nov. 1, 2007). The charged particles that make up the prominence are responding to powerful magnetic forces that compel the prominence to bend to the arcing field lines. But the forces are not constant: they are often in flux. We see this when the direction of the particles changes near the end of the clip. The material seen at this wavelength is heated to about 60,000 degrees.
The STEREO (behind) spa...
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Description The STEREO (behind) spacecraft observed this small prominence rising up from the Sun's surface, twisting around, and subsiding over about a 36-hour period (Oct. 31- Nov. 1, 2007). The charged particles that make up the prominence are responding to powerful magnetic forces that compel the prominence to bend to the arcing field lines. But the forces are not constant: they are often in flux. We see this when the direction of the particles changes near the end of the clip. The material seen at this wavelength is heated to about 60,000 degrees.
Joseph B. Gurman Normal Joseph B. Gurman 1 0 2002-02-27T15:45:00Z 2002-02-27T15:45:00Z 1 54 313 NASA GSGC 2 1 384 9.2511 800x600 150 0 0 Large magnetic loop as recorded by EIT in the Fe IX/X 171Å line. The temperature of this material is about 1 million K in the lower corona. The large loop on the right arches over an active region. The extreme ultraviolet image enables us to see tight, loop-like magnetic fields that extend above the Sun's surface around which charged particles are spinning (27 February 2002).
Joseph B. Gurman Normal...
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Description Joseph B. Gurman Normal Joseph B. Gurman 1 0 2002-02-27T15:45:00Z 2002-02-27T15:45:00Z 1 54 313 NASA GSGC 2 1 384 9.2511 800x600 150 0 0 Large magnetic loop as recorded by EIT in the Fe IX/X 171Å line. The temperature of this material is about 1 million K in the lower corona. The large loop on the right arches over an active region. The extreme ultraviolet image enables us to see tight, loop-like magnetic fields that extend above the Sun's surface around which charged particles are spinning (27 February 2002).
STEREO captured three differently shaped CMEs (coronal mass ejections) blasting out from the Sun over a three-day span (November 14-17, 2007). The COR2 (ahead) coronagraph, taking an image very 20 minutes, lets us generate a smooth motion movie of these events. The first CME billowed out as a doughnut-shaped CME to the lower right. The second one, late on Nov. 15, was a much more diffuse, "halo" CME that seemed to create a faint halo around the Sun as it expanded in all directions. In this instance it was determined that it originated from the backside of the Sun. The last CME was the more traditionally bulbous-shaped CME, more compact, distinct and brighter than the other two. These three represent one of the Sun's busiest periods in months.
STEREO captured three d...
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Description STEREO captured three differently shaped CMEs (coronal mass ejections) blasting out from the Sun over a three-day span (November 14-17, 2007). The COR2 (ahead) coronagraph, taking an image very 20 minutes, lets us generate a smooth motion movie of these events. The first CME billowed out as a doughnut-shaped CME to the lower right. The second one, late on Nov. 15, was a much more diffuse, "halo" CME that seemed to create a faint halo around the Sun as it expanded in all directions. In this instance it was determined that it originated from the backside of the Sun. The last CME was the more traditionally bulbous-shaped CME, more compact, distinct and brighter than the other two. These three represent one of the Sun's busiest periods in months.
SOHO has observed (Dec. 13, 2007) what may be the first indication of a "reversed" magnetic polarity region when compared to the current solar cycle, something scientists consider to be a crucial indicator that the new sunspot cycle is about upon us. This so-called plage region did not have a strong enough magnetic field to form a sunspot, but scientists believe that it may nevertheless stand as an icon that the old cycle is ending and a new one, Cycle 24, is about to begin. Sunspots appear in groups with north and south polarities just like a magnet. In magnetic images of the Sun taken (by SOHO's MDI instrument) during the last solar cycle, sunspots in the northern hemisphere of the Sun have had white areas preceding the black; in this new spot, we can clearly see that black precedes white. (This orientation is reversed in the southern hemisphere.) Solar cycles (in which the general level of solar activity is measured by numbers of sunspots) last from 9.5 to 13.5 years and have been recorded since the 1700's. The video clip fades from an extreme ultraviolet image of the Sun to zoom in on a magnetic image of the active region to show the correlation between the two.
SOHO has observed (Dec....
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Description SOHO has observed (Dec. 13, 2007) what may be the first indication of a "reversed" magnetic polarity region when compared to the current solar cycle, something scientists consider to be a crucial indicator that the new sunspot cycle is about upon us. This so-called plage region did not have a strong enough magnetic field to form a sunspot, but scientists believe that it may nevertheless stand as an icon that the old cycle is ending and a new one, Cycle 24, is about to begin. Sunspots appear in groups with north and south polarities just like a magnet. In magnetic images of the Sun taken (by SOHO's MDI instrument) during the last solar cycle, sunspots in the northern hemisphere of the Sun have had white areas preceding the black; in this new spot, we can clearly see that black precedes white. (This orientation is reversed in the southern hemisphere.) Solar cycles (in which the general level of solar activity is measured by numbers of sunspots) last from 9.5 to 13.5 years and have been recorded since the 1700's. The video clip fades from an extreme ultraviolet image of the Sun to zoom in on a magnetic image of the active region to show the correlation between the two.
Foreshadowing is a literary device to hint at what is coming later in a story. We are going to engage in a little foreshadowing with the Sun. As of the beginning of March 19, 2007, there were no sunspots on the Sun and no indication of when any activity would be observable. And even on March 20, no sunspots could be observed in the ultraviolet wavelengths of light or even filtered white light. But like storm clouds on a horizon, disturbances above an active region had already begun to come into view on the edge of the Sun in the ultraviolet images from SOHO. Initially, we saw some brightening at the Sun's edge and then, a half a day later or so, loops of particles spiraling above the edge of the Sun could be spotted. At this point, we could foretell what was coming next. By the 21st, an active region itself could be seen as it rotated into view. The extreme ultraviolet images told the tale. In the next day or so, the active region should be able to be seen as sunspots in the white light images and magnetic as well with the Sun's rotation bringing them around from the very edge. Active regions are the source of many solar storms.
Foreshadowing is a lite...
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Description Foreshadowing is a literary device to hint at what is coming later in a story. We are going to engage in a little foreshadowing with the Sun. As of the beginning of March 19, 2007, there were no sunspots on the Sun and no indication of when any activity would be observable. And even on March 20, no sunspots could be observed in the ultraviolet wavelengths of light or even filtered white light. But like storm clouds on a horizon, disturbances above an active region had already begun to come into view on the edge of the Sun in the ultraviolet images from SOHO. Initially, we saw some brightening at the Sun's edge and then, a half a day later or so, loops of particles spiraling above the edge of the Sun could be spotted. At this point, we could foretell what was coming next. By the 21st, an active region itself could be seen as it rotated into view. The extreme ultraviolet images told the tale. In the next day or so, the active region should be able to be seen as sunspots in the white light images and magnetic as well with the Sun's rotation bringing them around from the very edge. Active regions are the source of many solar storms.
CME blast -- A large coronal mass ejection ejects a cloud of particles into space on 2 December 2003. In this composite an EIT 304 image of the sun from about the same time has been appropriately scaled and superimposed on a LASCO C2 image where a red occulting disk can be seen extending around the Sun. This LASCO coronagraph instrument allows details in the corona to be observed.
CME blast -- A large co...
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Description CME blast -- A large coronal mass ejection ejects a cloud of particles into space on 2 December 2003. In this composite an EIT 304 image of the sun from about the same time has been appropriately scaled and superimposed on a LASCO C2 image where a red occulting disk can be seen extending around the Sun. This LASCO coronagraph instrument allows details in the corona to be observed.
While it may look otherworldly, this is still just the Sun and its environs as seen from SOHO (July 24, 2007). By combining these three views onto one image we can try to suggest SOHO's expansive capacity to see the Sun itself and activity in its corona (the area around it) at virtually the same time. This composite image blends the Sun itself in extreme UV light (from EIT at 304 Angstroms) with the smaller expanse around it as seen from the LASCO C2 coronagraph), and the much larger view (from the LASCO C3 coronagraph), whose field of view is 30 solar radii. The Sun has been enlarged about 50% to cover the C2 occulting disk and we adjusted the color tables of the instruments to give it a unifying, single tone. While no solar storms were erupting, you can easily follow the structure of streamers extending out of the Sun in several directions.
While it may look other...
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Description While it may look otherworldly, this is still just the Sun and its environs as seen from SOHO (July 24, 2007). By combining these three views onto one image we can try to suggest SOHO's expansive capacity to see the Sun itself and activity in its corona (the area around it) at virtually the same time. This composite image blends the Sun itself in extreme UV light (from EIT at 304 Angstroms) with the smaller expanse around it as seen from the LASCO C2 coronagraph), and the much larger view (from the LASCO C3 coronagraph), whose field of view is 30 solar radii. The Sun has been enlarged about 50% to cover the C2 occulting disk and we adjusted the color tables of the instruments to give it a unifying, single tone. While no solar storms were erupting, you can easily follow the structure of streamers extending out of the Sun in several directions.
Joseph B. Gurman Normal Joseph B. Gurman 2 2003-03-04T14:52:00Z 2003-03-04T14:52:00Z 1 NASA GSGC 1 1 9.2511 800x600 0 0 This LASCO C2 image shows a very large coronal mass ejection(CME) blasting off into space on 2 December 2002.  It presents the classic shape of a CME:  a large bulbous front with a second,more compact, inner core of hot plasma. This material erupts away from the Sun at speeds of one to two millionsmiles (or km) per hour.
Joseph B. Gurman Normal...
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Description Joseph B. Gurman Normal Joseph B. Gurman 2 2003-03-04T14:52:00Z 2003-03-04T14:52:00Z 1 NASA GSGC 1 1 9.2511 800x600 0 0 This LASCO C2 image shows a very large coronal mass ejection(CME) blasting off into space on 2 December 2002.  It presents the classic shape of a CME:  a large bulbous front with a second,more compact, inner core of hot plasma. This material erupts away from the Sun at speeds of one to two millionsmiles (or km) per hour.
Active regions and magnetic loops as recorded by EIT in the Fe IX/X 171Å line. The temperature of this material is about 1 million K in the lower corona.
Active regions and magn...
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Description Active regions and magnetic loops as recorded by EIT in the Fe IX/X 171Å line. The temperature of this material is about 1 million K in the lower corona.
Over a period of four days (July 27 - 31, 2007) two active regions can be seen by SOHO communicating with each other magnetically. While the areas remained fairly stable, in that they did not generate any solar storms, the magnetic field lines of connection between them shift and sway most of the time. Like two magnets that sit near each other, the magnetic fields of the active regions share a dynamic interplay that is fun to watch. While we cannot actually see magnetic field lines, we can see charged particles in extreme ultraviolet light tracing the field lines above the surface of the Sun.
Over a period of four d...
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Description Over a period of four days (July 27 - 31, 2007) two active regions can be seen by SOHO communicating with each other magnetically. While the areas remained fairly stable, in that they did not generate any solar storms, the magnetic field lines of connection between them shift and sway most of the time. Like two magnets that sit near each other, the magnetic fields of the active regions share a dynamic interplay that is fun to watch. While we cannot actually see magnetic field lines, we can see charged particles in extreme ultraviolet light tracing the field lines above the surface of the Sun.
This week STEREO observed a nice gathering of solar prominences in profile as they twisted, stretched and floated just above the solar surface. Over about two and a half days (August 16-18, 2007), the prominences were seen in extreme ultraviolet light by the Ahead spacecraft. Prominences are clouds of cooler gases controlled by powerful magnetic forces that extend above the Sun's surface. The careful observer can sometimes see the gases arcing out from one point and sliding above the surface to another point. In the most interesting sequence near the end of the clip, the upper prominence seems to arch away into space. Such sequences serve to show the dynamic nature of the Sun.
This week STEREO observ...
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Description This week STEREO observed a nice gathering of solar prominences in profile as they twisted, stretched and floated just above the solar surface. Over about two and a half days (August 16-18, 2007), the prominences were seen in extreme ultraviolet light by the Ahead spacecraft. Prominences are clouds of cooler gases controlled by powerful magnetic forces that extend above the Sun's surface. The careful observer can sometimes see the gases arcing out from one point and sliding above the surface to another point. In the most interesting sequence near the end of the clip, the upper prominence seems to arch away into space. Such sequences serve to show the dynamic nature of the Sun.
Grab your 3D glasses (if you have any around) and get ready for something never seen before by anyone. We proudly present to you the first ever actual 3D stills and movies of the Sun from the twin STEREO spacecraft. These images were just released on April 23, 2007. And even if you can't see them in 3D, you can still enjoy the unsurpassed levels of detail in these 2D, full disk solar images with twice the resolution of SOHO. The still image taken on March 24, 2007 shows a coronal hole (darker region, right of center) and two active regions (large, bright area at the left of center and smaller one on the far right). This zoomed in view of the equatorial region of the Sun was created by combining images in three extreme ultraviolet wavelengths: 304, 171 and 195 angstroms. The video clips on the other hand cover March 17-March 27, 2007. They were taken by the EUVI telescope in the 171 angstroms wavelength, showing a portion of the equatorial region of the solar disk to give a close up view of the active region. Watching the active region in profile as it rotates into view is spectacular. But the fact that it is able to be seen in 3D for the first time ever makes it even more so. This marks a new kind of achievement in solar physics. Click here [ http://www.nasa.gov/mission_pages/stereo/news/stereo3D_press.html ] to see even more of the new images.
Grab your 3D glasses (i...<a target="_blank" href="http://www.nasa.gov/mission_pages/stereo/news/stereo3D_press.html"></a>
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Description Grab your 3D glasses (if you have any around) and get ready for something never seen before by anyone. We proudly present to you the first ever actual 3D stills and movies of the Sun from the twin STEREO spacecraft. These images were just released on April 23, 2007. And even if you can't see them in 3D, you can still enjoy the unsurpassed levels of detail in these 2D, full disk solar images with twice the resolution of SOHO. The still image taken on March 24, 2007 shows a coronal hole (darker region, right of center) and two active regions (large, bright area at the left of center and smaller one on the far right). This zoomed in view of the equatorial region of the Sun was created by combining images in three extreme ultraviolet wavelengths: 304, 171 and 195 angstroms. The video clips on the other hand cover March 17-March 27, 2007. They were taken by the EUVI telescope in the 171 angstroms wavelength, showing a portion of the equatorial region of the solar disk to give a close up view of the active region. Watching the active region in profile as it rotates into view is spectacular. But the fact that it is able to be seen in 3D for the first time ever makes it even more so. This marks a new kind of achievement in solar physics. Click here [ http://www.nasa.gov/mission_pages/stereo/news/stereo3D_press.html ] to see even more of the new images.
Grab your 3D glasses (if you have any around) and get ready for something never seen before by anyone. We proudly present to you the first ever actual 3D stills and movies of the Sun from the twin STEREO spacecraft. These images were just released on April 23, 2007. And even if you can't see them in 3D, you can still enjoy the unsurpassed levels of detail in these 2D, full disk solar images with twice the resolution of SOHO. The still image taken on March 24, 2007 shows a coronal hole (darker region, right of center) and two active regions (large, bright area at the left of center and smaller one on the far right). This zoomed in view of the equatorial region of the Sun was created by combining images in three extreme ultraviolet wavelengths: 304, 171 and 195 angstroms. The video clips on the other hand cover March 17-March 27, 2007. They were taken by the EUVI telescope in the 171 angstroms wavelength, showing a portion of the equatorial region of the solar disk to give a close up view of the active region. Watching the active region in profile as it rotates into view is spectacular. But the fact that it is able to be seen in 3D for the first time ever makes it even more so. This marks a new kind of achievement in solar physics. Click here [ http://www.nasa.gov/mission_pages/stereo/news/stereo3D_press.html ] to see even more of the new images.
Grab your 3D glasses (i...<a target="_blank" href="http://www.nasa.gov/mission_pages/stereo/news/stereo3D_press.html"></a>
Image
 
Description Grab your 3D glasses (if you have any around) and get ready for something never seen before by anyone. We proudly present to you the first ever actual 3D stills and movies of the Sun from the twin STEREO spacecraft. These images were just released on April 23, 2007. And even if you can't see them in 3D, you can still enjoy the unsurpassed levels of detail in these 2D, full disk solar images with twice the resolution of SOHO. The still image taken on March 24, 2007 shows a coronal hole (darker region, right of center) and two active regions (large, bright area at the left of center and smaller one on the far right). This zoomed in view of the equatorial region of the Sun was created by combining images in three extreme ultraviolet wavelengths: 304, 171 and 195 angstroms. The video clips on the other hand cover March 17-March 27, 2007. They were taken by the EUVI telescope in the 171 angstroms wavelength, showing a portion of the equatorial region of the solar disk to give a close up view of the active region. Watching the active region in profile as it rotates into view is spectacular. But the fact that it is able to be seen in 3D for the first time ever makes it even more so. This marks a new kind of achievement in solar physics. Click here [ http://www.nasa.gov/mission_pages/stereo/news/stereo3D_press.html ] to see even more of the new images.
This is one of the clearest and most engaging clips of solar plasma shimmying and arcing above the edge of the Sun that we have ever been able to view (May 9-10, 2007). With STEREO's high frame rate (an image every few minutes) and high resolution, we can zoom in on areas of interest yet maintain image clarity. This large sunspot was just rotating to the edge of the Sun when we zoomed in on its action for about 18 hours. The active region, a hot bed of intense magnetic forces, is the source of almost all of the activity we see. It spurts out plasma about six or seven times in arcing bursts, all of which is controlled by powerful magnetic forces that sweep the material back into the Sun. It should be noted that the rate at which the images were captured changed roughly half way through the clip, so that the pacing seems to slow down. These were taken in of extreme ultraviolet light at 304 Angstroms from the Behind spacecraft. Credit: NASA/STEREO/Naval Research Laboratory
This is one of the clea...
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Description This is one of the clearest and most engaging clips of solar plasma shimmying and arcing above the edge of the Sun that we have ever been able to view (May 9-10, 2007). With STEREO's high frame rate (an image every few minutes) and high resolution, we can zoom in on areas of interest yet maintain image clarity. This large sunspot was just rotating to the edge of the Sun when we zoomed in on its action for about 18 hours. The active region, a hot bed of intense magnetic forces, is the source of almost all of the activity we see. It spurts out plasma about six or seven times in arcing bursts, all of which is controlled by powerful magnetic forces that sweep the material back into the Sun. It should be noted that the rate at which the images were captured changed roughly half way through the clip, so that the pacing seems to slow down. These were taken in of extreme ultraviolet light at 304 Angstroms from the Behind spacecraft. Credit: NASA/STEREO/Naval Research Laboratory
Double CME -- This LASCO C2 coronograph image from 8 November 2000 shows what appears to be two CMEs heading in symmetrically Double CME -- This LASCO C2 coronograph image from 8 November 2000 shows what appears to be two CMEs heading in symmetrically opposite directions from the Sun. An EIT 304Å image from the same day has been superimposed over the dark disk which blocks the Sun so that the LASCO instrument can observe the structures of the corona in visible light.
Double CME -- This LASC...
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Description Double CME -- This LASCO C2 coronograph image from 8 November 2000 shows what appears to be two CMEs heading in symmetrically Double CME -- This LASCO C2 coronograph image from 8 November 2000 shows what appears to be two CMEs heading in symmetrically opposite directions from the Sun. An EIT 304Å image from the same day has been superimposed over the dark disk which blocks the Sun so that the LASCO instrument can observe the structures of the corona in visible light.
LASCO C2/C3 composite image series showing a CME cloud emerging from the Sun and an ensuing proton blast that struck the SOHO instrument on 5 November 1998. Protons accelerated to 10% the speed of light arrived at SOHO in about an hour, causing numerous bright points and streaks in the last two images.
LASCO C2/C3 composite i...
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Description LASCO C2/C3 composite image series showing a CME cloud emerging from the Sun and an ensuing proton blast that struck the SOHO instrument on 5 November 1998. Protons accelerated to 10% the speed of light arrived at SOHO in about an hour, causing numerous bright points and streaks in the last two images.
Blasting CME -- This LASCO C2 image, taken 8 January 2002, shows a widely spreading coronal mass ejection (CME) shooting billi Joseph B. Gurman Normal Joseph B. Gurman 2 2003-01-03T14:46:00Z 2003-01-03T14:46:00Z 1 NASA GSGC 1 1 9.2511 800x600 0 0 CME blast -- This dramatic coronal mass ejection was captured 7 August 2002 as it blasted billions of tons of particles millions of miles per hour out into space.  The image was taken by the LASCO C2 instrument, which blocks out the Sun with an occulting disk so that we can see the fine details of the faint corona.  An EIT 284Å image of the Sun itself, taken at about the same time, was enlarged and superimposed on the occulting disk.
Blasting CME -- This LA...
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Description Blasting CME -- This LASCO C2 image, taken 8 January 2002, shows a widely spreading coronal mass ejection (CME) shooting billi Joseph B. Gurman Normal Joseph B. Gurman 2 2003-01-03T14:46:00Z 2003-01-03T14:46:00Z 1 NASA GSGC 1 1 9.2511 800x600 0 0 CME blast -- This dramatic coronal mass ejection was captured 7 August 2002 as it blasted billions of tons of particles millions of miles per hour out into space.  The image was taken by the LASCO C2 instrument, which blocks out the Sun with an occulting disk so that we can see the fine details of the faint corona.  An EIT 284Å image of the Sun itself, taken at about the same time, was enlarged and superimposed on the occulting disk.
A comparison of three images over four years apart illustrates how the level of solar activity has risen from near minimum to near maximum in the Sun's 11-years solar cycle. These images are captured using He II 304 ? emissions showing the solar corona at a temperature of about 60,000 degrees K. Many more sunspots, solar flares, and coronal mass ejections occur during the solar maximum. The increase in activity can be seen in the number of white areas, i.e., indicators of strong magnetic intensity .
A comparison of three i...
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Description A comparison of three images over four years apart illustrates how the level of solar activity has risen from near minimum to near maximum in the Sun's 11-years solar cycle. These images are captured using He II 304 ? emissions showing the solar corona at a temperature of about 60,000 degrees K. Many more sunspots, solar flares, and coronal mass ejections occur during the solar maximum. The increase in activity can be seen in the number of white areas, i.e., indicators of strong magnetic intensity .
Solar study spacecraft from a number of missions observe the Sun in various wavelengths of light every day. This representative collage, made from images taken on November 25, 2007, suggests some (but not all) of the various missions and wavelengths that are captured and made available on the web daily. By observing in different wavelengths of light the instruments show different features of the Sun at different temperatures and elevations above the surface. And when you consider the two STEREO spacecraft, separated by 41 degrees of perspective, then we add another dimension to our observations. For the first time, we can observe that much more of the Sun. Taken together, these spacecraft and their images provide scientists with a whole range of information about the Sun and its processes. (The title is a paraphrase Elizabeth Barrett Browning's sonnet, "How do I love thee? Let me count the ways.")
Solar study spacecraft ...
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Description Solar study spacecraft from a number of missions observe the Sun in various wavelengths of light every day. This representative collage, made from images taken on November 25, 2007, suggests some (but not all) of the various missions and wavelengths that are captured and made available on the web daily. By observing in different wavelengths of light the instruments show different features of the Sun at different temperatures and elevations above the surface. And when you consider the two STEREO spacecraft, separated by 41 degrees of perspective, then we add another dimension to our observations. For the first time, we can observe that much more of the Sun. Taken together, these spacecraft and their images provide scientists with a whole range of information about the Sun and its processes. (The title is a paraphrase Elizabeth Barrett Browning's sonnet, "How do I love thee? Let me count the ways.")
Image of two coronal mass ejections 31 May 2001 taken by LASCO C2. Nearly simultaneously,  two CMEs blast into opposite directions from the Sun, a fairly uncommon observation. CMEs eject a billion tons of particles traveling millions of miles an hour. The dark disk blocks the Sun so that the LASCO instrument can observe the structures of the corona in visible light.
Image of two coronal ma...
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Description Image of two coronal mass ejections 31 May 2001 taken by LASCO C2. Nearly simultaneously,  two CMEs blast into opposite directions from the Sun, a fairly uncommon observation. CMEs eject a billion tons of particles traveling millions of miles an hour. The dark disk blocks the Sun so that the LASCO instrument can observe the structures of the corona in visible light.
LASCO C2 coronograph image in which a twisting, helical-shaped CME spins off from the Sun. This particular CME and erupting prominence is somewhat unusual in that the width of the blast is relatively narrow and the strands of plasma are twisting. The dark disk blocks the Sun so that the LASCO instrument can observe the structures of the corona in visible light. The white circle represents the size and position of the Sun.
LASCO C2 coronograph im...
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Description LASCO C2 coronograph image in which a twisting, helical-shaped CME spins off from the Sun. This particular CME and erupting prominence is somewhat unusual in that the width of the blast is relatively narrow and the strands of plasma are twisting. The dark disk blocks the Sun so that the LASCO instrument can observe the structures of the corona in visible light. The white circle represents the size and position of the Sun.
SOHO is keeping a close eye on a good-sized active region that is rotating into view. The video clip covers 36 hours (June 27-28, 2007) as the bright glow and arcs above the solar surface appear before we can actually see a sunspot on the surface of the Sun. The images were taken in extreme ultraviolet light at the 195 Angstrom wavelength. There have not been very many sunspots over the past year or so, so this one is generating some interest among solar observers. The sunspot that preceded it by a few days has generated some modest flares. Maybe this one will display even more firepower?
SOHO is keeping a close...
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Description SOHO is keeping a close eye on a good-sized active region that is rotating into view. The video clip covers 36 hours (June 27-28, 2007) as the bright glow and arcs above the solar surface appear before we can actually see a sunspot on the surface of the Sun. The images were taken in extreme ultraviolet light at the 195 Angstrom wavelength. There have not been very many sunspots over the past year or so, so this one is generating some interest among solar observers. The sunspot that preceded it by a few days has generated some modest flares. Maybe this one will display even more firepower?
A close-up of an active region of the Sun from STEREO's Ahead spacecraft in extreme ultraviolet revealed an interesting, yet subtle, phenomenon. Besides a pair of small eruptions over this 40-hour period (Aug. 23-24, 2007), one small point was the source of a steady outpouring of material in all directions around it during the whole time, almost like a sparkler. It may not be an actual outflow into the solar wind - these are likely just the footprints of longer loops that continue upwards at other temperatures. The flow may be due to an imbalance in the heating of the loops. Understanding how and where such loops are heated is a 'hot' topic in solar research.
A close-up of an active...
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Description A close-up of an active region of the Sun from STEREO's Ahead spacecraft in extreme ultraviolet revealed an interesting, yet subtle, phenomenon. Besides a pair of small eruptions over this 40-hour period (Aug. 23-24, 2007), one small point was the source of a steady outpouring of material in all directions around it during the whole time, almost like a sparkler. It may not be an actual outflow into the solar wind - these are likely just the footprints of longer loops that continue upwards at other temperatures. The flow may be due to an imbalance in the heating of the loops. Understanding how and where such loops are heated is a 'hot' topic in solar research.
An image sequence over less than two hours of a coronal mass ejection 7 April 1997 taken by LASCO C2. In this sequence a CME blasts into space a billion tons of particles travelling millions of miles an hour.
An image sequence over ...
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Description An image sequence over less than two hours of a coronal mass ejection 7 April 1997 taken by LASCO C2. In this sequence a CME blasts into space a billion tons of particles travelling millions of miles an hour.
A composite of three images of a large CME. The images are from EIT (the blue Sun in the center) and the LASCO C2/C3 instruments.
A composite of three im...
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Description A composite of three images of a large CME. The images are from EIT (the blue Sun in the center) and the LASCO C2/C3 instruments.
Active region loops observed on the West limb.
Active region loops obs...
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Description Active region loops observed on the West limb.
The complex distribution and mixing of magnetic polarities (here displayed as yellow and blue) form a "magnetic carpet" over the entire Sun (upper right panel). The upper left panel shows the EUV emission taken simultaneously by CDS from plasma at the temperature of 250 000 K. The lower panel shows an overlay of the two images. Sequences of such images show that many of the transition region brightenings correspond to changes in the magnetic field.
The complex distributio...
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Description The complex distribution and mixing of magnetic polarities (here displayed as yellow and blue) form a "magnetic carpet" over the entire Sun (upper right panel). The upper left panel shows the EUV emission taken simultaneously by CDS from plasma at the temperature of 250 000 K. The lower panel shows an overlay of the two images. Sequences of such images show that many of the transition region brightenings correspond to changes in the magnetic field.
An eruption seen over the limb in the extreme-ultraviolet emission line of Oxygen V at 630 Angstroms. This CDS image shows material streaming back at high velocity onto the disk after the eruption. The left image shows intensity, while the middle and right show the Doppler velocity and width respectively. The blue color of the middle image represents material moving at greater than 200 kilometers per second toward the Sun. In the right image, the unresolved motions represented by the Doppler width reach as high as 300 kilometers per second.
An eruption seen over t...
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Description An eruption seen over the limb in the extreme-ultraviolet emission line of Oxygen V at 630 Angstroms. This CDS image shows material streaming back at high velocity onto the disk after the eruption. The left image shows intensity, while the middle and right show the Doppler velocity and width respectively. The blue color of the middle image represents material moving at greater than 200 kilometers per second toward the Sun. In the right image, the unresolved motions represented by the Doppler width reach as high as 300 kilometers per second.
The left panel shows a monochromatic image of an eruption above the east limb observed in O V 629 ? on 19 May 1998. Line profiles in three spatial positions, A, B and C, have been marked and are displayed in the panel to the right. The area marked C represents the average disk profile with zero velocity. From the line shifts one can derive the line-of-sight velocity of the emitting plasma.
The left panel shows a ...
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Description The left panel shows a monochromatic image of an eruption above the east limb observed in O V 629 ? on 19 May 1998. Line profiles in three spatial positions, A, B and C, have been marked and are displayed in the panel to the right. The area marked C represents the average disk profile with zero velocity. From the line shifts one can derive the line-of-sight velocity of the emitting plasma.
The images were derived from full disk scans by CDS on 23 April 1998. As the temperature increases, the radiation comes from higher layers of the solar atmosphere, or corona, and is more strongly associated with solar activity. At the very highest temperatures, only the hot loops above active regions are visible. Scientists use images like these to probe the temperature structure of the solar atmosphere.
The images were derived...
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Description The images were derived from full disk scans by CDS on 23 April 1998. As the temperature increases, the radiation comes from higher layers of the solar atmosphere, or corona, and is more strongly associated with solar activity. At the very highest temperatures, only the hot loops above active regions are visible. Scientists use images like these to probe the temperature structure of the solar atmosphere.
A bright and expansive coronal mass ejection (CME) unfurled itself on January 24, 2007. As seen in SOHO's LASCO C2 coronagraph, the bright front emerged in the shape of an arc from behind the occulting disk but soon expanded into a ragged, bulbous shape with lots of structural lines inside it. The source of this CME was an active region that had just began to rotate into view the next day. An EIT 304 Angstrom image of the Sun taken at nearly the same time was enlarged and superimposed on the occulting disk.
A bright and expansive ...
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Description A bright and expansive coronal mass ejection (CME) unfurled itself on January 24, 2007. As seen in SOHO's LASCO C2 coronagraph, the bright front emerged in the shape of an arc from behind the occulting disk but soon expanded into a ragged, bulbous shape with lots of structural lines inside it. The source of this CME was an active region that had just began to rotate into view the next day. An EIT 304 Angstrom image of the Sun taken at nearly the same time was enlarged and superimposed on the occulting disk.
Observing the Sun with a spectrometer like CDS one can derive the intensity and velocity distribution of the O V 629 ? line formed at approximately 230 000 K in AR8737. Pixels with Doppler shifts corresponding to a velocity greater than ?40 km/s is fully red/blue. Contours outline areas with velocities exceeding ?50 km/s. The velocities are calculated relative to the part of the solar disk (to the left) that is within the field of view.
Observing the Sun with ...
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Description Observing the Sun with a spectrometer like CDS one can derive the intensity and velocity distribution of the O V 629 ? line formed at approximately 230 000 K in AR8737. Pixels with Doppler shifts corresponding to a velocity greater than ?40 km/s is fully red/blue. Contours outline areas with velocities exceeding ?50 km/s. The velocities are calculated relative to the part of the solar disk (to the left) that is within the field of view.
Huge magnetic loops extending tens of thousands of km into space trapping hot gases inside them. We have seen such loop systems develop into extremely complex so-called 'active regions' where loops clash and twist like elastic bands before some kind of break down results in the ejection of clouds or streams of particles into space. The images show CDS' unique ability to map such regions. The coolest gases (20,000 degrees) are shown in the top left image, and the hottest (2 million degrees) in the bottom right. The edge of the Sun is seen on the left of each image and different gases show different loops giving a spectacular display above the surface of the Sun.
Huge magnetic loops ext...
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Description Huge magnetic loops extending tens of thousands of km into space trapping hot gases inside them. We have seen such loop systems develop into extremely complex so-called 'active regions' where loops clash and twist like elastic bands before some kind of break down results in the ejection of clouds or streams of particles into space. The images show CDS' unique ability to map such regions. The coolest gases (20,000 degrees) are shown in the top left image, and the hottest (2 million degrees) in the bottom right. The edge of the Sun is seen on the left of each image and different gases show different loops giving a spectacular display above the surface of the Sun.
Progress of a Coronal Mass Ejection (CME) observed over an eight hour period on 5-6 August 1999 by LASCO C3. The dark disk blocks the Sun so that the LASCO instrument can observe the structures of the corona in visible light. The white circle represents the size and position of the Sun.
Progress of a Coronal M...
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Description Progress of a Coronal Mass Ejection (CME) observed over an eight hour period on 5-6 August 1999 by LASCO C3. The dark disk blocks the Sun so that the LASCO instrument can observe the structures of the corona in visible light. The white circle represents the size and position of the Sun.
Before, during and after - a blinker event in O V (30,000 x 74,000 km). The three images are minutes apart in time.
Before, during and afte...
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Description Before, during and after - a blinker event in O V (30,000 x 74,000 km). The three images are minutes apart in time.
A comparison of two EIT images almost two years apart illustrates how the level of solar activity has increased significantly. The Sun attains its expected sunspot maximum in the year 2000. These images are captured using Fe IX-X 171 Å emission showing the solar corona at a temperature of about 1.3 million K. Many more sunspots, solar flares, and coronal mass ejections occur during the solar maximum. The numerous active regions and the number/size of magnetic loops in the recent image shows the increase.
A comparison of two EIT...
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Description A comparison of two EIT images almost two years apart illustrates how the level of solar activity has increased significantly. The Sun attains its expected sunspot maximum in the year 2000. These images are captured using Fe IX-X 171 Å emission showing the solar corona at a temperature of about 1.3 million K. Many more sunspots, solar flares, and coronal mass ejections occur during the solar maximum. The numerous active regions and the number/size of magnetic loops in the recent image shows the increase.
EIT full sun images in Fe XII 195 A (left), Fe IX/X 171 A (middle), and the ratio of these two images (right). The latter one gives an indication of the temperature distribution in the Sun's corona with dark areas being cooler regions and bright areas being hotter. These images were recorded on 12 May 1996.
EIT full sun images in ...
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Description EIT full sun images in Fe XII 195 A (left), Fe IX/X 171 A (middle), and the ratio of these two images (right). The latter one gives an indication of the temperature distribution in the Sun's corona with dark areas being cooler regions and bright areas being hotter. These images were recorded on 12 May 1996.
Cutaway - The three major zones of the Sun's internal structure are shown in this cutaway of an EIT 304 image. The core (temperature of 15 million degrees) is where the nuclear fusion occurs. In the large radiative zone the plasma and energy are gradually moved outwards from the core over a period of thousands of years. Finally, the hot plasma is cycled through a convection process (represented by the series of circles) in the convection zone up to the surface and out into space.
Cutaway - The three maj...
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Description Cutaway - The three major zones of the Sun's internal structure are shown in this cutaway of an EIT 304 image. The core (temperature of 15 million degrees) is where the nuclear fusion occurs. In the large radiative zone the plasma and energy are gradually moved outwards from the core over a period of thousands of years. Finally, the hot plasma is cycled through a convection process (represented by the series of circles) in the convection zone up to the surface and out into space.
SOHO-EIT image in resonance lines of eleven times ionized iron (Fe XII) at 195 Angstroms in the extreme ultraviolet showing the solar corona at a temperature of about 1 million K. This image was recorded on 11 September 1997. It is dominated by two large active region systems, composed of numerous magnetic loops.
SOHO-EIT image in reson...
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Description SOHO-EIT image in resonance lines of eleven times ionized iron (Fe XII) at 195 Angstroms in the extreme ultraviolet showing the solar corona at a temperature of about 1 million K. This image was recorded on 11 September 1997. It is dominated by two large active region systems, composed of numerous magnetic loops.
A time series of SOHO-EIT images showing the development of a huge, eruptive prominence on 1997 August 27. The images were obtained with EIT's unique, normal-incidence, multilayer-coated telescope in the resonance line of singly ionized helium (He II) at 304 Angstroms in the extreme ultraviolet. The material in the eruptive prominence is at temperatures of 60,000 - 80,000 K, much cooler than surrounding corona, which is typically at temperatures above 1 million K. By the fourth frame, the prominence is over 350,000 km (216,000 miles) across, large enough to span 28 earths. Credit --- The SOHO-EIT Consortium: SOHO is an ESA/NASA project of international cooperation.
A time series of SOHO-E...
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Description A time series of SOHO-EIT images showing the development of a huge, eruptive prominence on 1997 August 27. The images were obtained with EIT's unique, normal-incidence, multilayer-coated telescope in the resonance line of singly ionized helium (He II) at 304 Angstroms in the extreme ultraviolet. The material in the eruptive prominence is at temperatures of 60,000 - 80,000 K, much cooler than surrounding corona, which is typically at temperatures above 1 million K. By the fourth frame, the prominence is over 350,000 km (216,000 miles) across, large enough to span 28 earths. Credit --- The SOHO-EIT Consortium: SOHO is an ESA/NASA project of international cooperation.
SOHO-EIT image from 14 September 1997 showing a huge eruptive prominence in the resonance line of singly ionized helium (He II) at 304 Angstroms in the extreme ultraviolet. The material in the eruptive prominence is at temperatures of 60,000 - 80,000 K, much cooler than the surrounding corona, which is typically at temperatures above 1 million K.
SOHO-EIT image from 14 ...
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Description SOHO-EIT image from 14 September 1997 showing a huge eruptive prominence in the resonance line of singly ionized helium (He II) at 304 Angstroms in the extreme ultraviolet. The material in the eruptive prominence is at temperatures of 60,000 - 80,000 K, much cooler than the surrounding corona, which is typically at temperatures above 1 million K.
Ratio of EIT full Sun images in Fe XII 195A to Fe IX/X 171A as recorded on 19 September 1997 at 01:00 UT. This line ratio gives an indication of the temperature distribution in the Sun's corona with dark areas being cooler regions and bright areas being hotter. Note the distinctive temperature differences in the numerous magnetic loops and the hot extended regions in the outer corona at both the West and East limb. The coronal holes at the North and South pole clearly show up as "cooler" regions.
Ratio of EIT full Sun i...
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Description Ratio of EIT full Sun images in Fe XII 195A to Fe IX/X 171A as recorded on 19 September 1997 at 01:00 UT. This line ratio gives an indication of the temperature distribution in the Sun's corona with dark areas being cooler regions and bright areas being hotter. Note the distinctive temperature differences in the numerous magnetic loops and the hot extended regions in the outer corona at both the West and East limb. The coronal holes at the North and South pole clearly show up as "cooler" regions.
Sequence of SOHO/EIT images showing a shock wave running across the solar disk. The shock wave originated in the vicinity of a flaring solar active region; the flare began on 1997 April 7 at 13:59 UT, in conjunction with the flare, a large "halo" coronal mass ejection (CME) (see LASCO image http://sohowww.nascom.nasa.gov/gallery/LASCO/las015.gif and the special page on the 1997 April 7-9 solar-terrestrial event, http://umbra.nascom.nasa.gov/eit/cme/april7/index.html . EIT recorded these images in emission lines of Fe XII at 195 A; this ion is formed at temperature of about 1.5 million degrees. Since the shock is relatively difficult to see in the original images, displayed here are running difference images, i.e. each image shows the difference from the previous image. The speed at which the the shock wave runs across the solar disk was estimated at 1.5 million km/h - supersonic even for the Sun!
Sequence of SOHO/EIT im...<a target="_blank" href="http://sohowww.nascom.nasa.gov/gallery/LASCO/las015.gif"></a><a target="_blank" href="http://umbra.nascom.nasa.gov/eit/cme/april7/index.html"></a>
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Description Sequence of SOHO/EIT images showing a shock wave running across the solar disk. The shock wave originated in the vicinity of a flaring solar active region; the flare began on 1997 April 7 at 13:59 UT, in conjunction with the flare, a large "halo" coronal mass ejection (CME) (see LASCO image http://sohowww.nascom.nasa.gov/gallery/LASCO/las015.gif and the special page on the 1997 April 7-9 solar-terrestrial event, http://umbra.nascom.nasa.gov/eit/cme/april7/index.html . EIT recorded these images in emission lines of Fe XII at 195 A; this ion is formed at temperature of about 1.5 million degrees. Since the shock is relatively difficult to see in the original images, displayed here are running difference images, i.e. each image shows the difference from the previous image. The speed at which the the shock wave runs across the solar disk was estimated at 1.5 million km/h - supersonic even for the Sun!
An EIT 304Å image captures a pair of curving erupting prominences on 28 June 2000 -- Prominences are huge clouds of relatively cool dense plasma suspended in the Sun's hot, thin corona. At times, they can erupt, escaping the Sun's atmosphere. Emission in this spectral line shows the upper chromosphere at a temperature of about 60,000 degrees K. Every feature in the image traces magnetic field structure. The hottest areas appear almost white, while the darker red areas indicate cooler temperatures.
An EIT 304Å image captu...
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Description An EIT 304Å image captures a pair of curving erupting prominences on 28 June 2000 -- Prominences are huge clouds of relatively cool dense plasma suspended in the Sun's hot, thin corona. At times, they can erupt, escaping the Sun's atmosphere. Emission in this spectral line shows the upper chromosphere at a temperature of about 60,000 degrees K. Every feature in the image traces magnetic field structure. The hottest areas appear almost white, while the darker red areas indicate cooler temperatures.
SOHO-EIT image in resonance lines of eight and nine times ionized iron (Fe IX/X) at 171 Angstroms in the extreme ultraviolet showing the solar corona at a temperature of about 1 million K. This image was recorded on 11 September 1997. It is dominated by two large active region systems, composed of numerous magnetic loops.
SOHO-EIT image in reson...
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Description SOHO-EIT image in resonance lines of eight and nine times ionized iron (Fe IX/X) at 171 Angstroms in the extreme ultraviolet showing the solar corona at a temperature of about 1 million K. This image was recorded on 11 September 1997. It is dominated by two large active region systems, composed of numerous magnetic loops.
Bulbous prominence -- An EIT 304Å image of a large, twirling prominence taken on February 12, 2001 Bulbous prominence -- An EIT 304Å image of a large, twirling prominence taken on February 12, 2001. Prominences are huge clouds of relatively cool dense plasma suspended in the Sun's hot, thin corona. At times, they can extend outward and break away from the Sun's atmosphere. This image shows ions of helium heated at 60,000 degrees C.
Bulbous prominence -- A...
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Description Bulbous prominence -- An EIT 304Å image of a large, twirling prominence taken on February 12, 2001 Bulbous prominence -- An EIT 304Å image of a large, twirling prominence taken on February 12, 2001. Prominences are huge clouds of relatively cool dense plasma suspended in the Sun's hot, thin corona. At times, they can extend outward and break away from the Sun's atmosphere. This image shows ions of helium heated at 60,000 degrees C.
A SOHO-EIT image showing a huge eruptive prominence in the resonance line of singly ionized helium (He II) at 304 Angstroms in the extreme ultraviolet. While the filament was active at least nine hours before this exposure, the eruption started less than three hours before this image was obtained (1997 August 26 at 16:07 UT). The material in the eruptive prominence is at temperatures of 60,000 - 80,000 K, much cooler than surrounding corona, which is typically at temperatures above 1 million K. The prominence is over 350,000 km (216,000 miles) across, large enough to span 28 earths. Credit --- The SOHO-EIT Consortium: SOHO is an ESA/NASA project of international cooperation.
A SOHO-EIT image showin...
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Description A SOHO-EIT image showing a huge eruptive prominence in the resonance line of singly ionized helium (He II) at 304 Angstroms in the extreme ultraviolet. While the filament was active at least nine hours before this exposure, the eruption started less than three hours before this image was obtained (1997 August 26 at 16:07 UT). The material in the eruptive prominence is at temperatures of 60,000 - 80,000 K, much cooler than surrounding corona, which is typically at temperatures above 1 million K. The prominence is over 350,000 km (216,000 miles) across, large enough to span 28 earths. Credit --- The SOHO-EIT Consortium: SOHO is an ESA/NASA project of international cooperation.
Ratio of EIT full Sun images in Fe XII 195A to Fe IX/X 171A as recorded on 12 May 1996 between 06:53 and 06:59 UT. This line ratio gives an indication of the temperature distribution in the Sun's corona with dark areas being cooler regions and bright areas being hotter.
Ratio of EIT full Sun i...
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Description Ratio of EIT full Sun images in Fe XII 195A to Fe IX/X 171A as recorded on 12 May 1996 between 06:53 and 06:59 UT. This line ratio gives an indication of the temperature distribution in the Sun's corona with dark areas being cooler regions and bright areas being hotter.
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