Archive for category SDO
A colleague who works with LASCO data yesterday found this lovely spiralling eruption close to the south pole.
It’s a great example of how the magnetic field can influence the dynamics of erupting plasma. The eruption starts around 00:13 in the above video.
YouTube and Helioviewer.org user sedge2002 found another coronal cavity. This one was on the Sun late 2011 to early 2012. It appears towards the end of this movie, at around 30-45 degrees clockwise from the north pole of Sun, above the limb:
Thanks to sedge2002 for making this movie and sharing it with other users of Helioviewer.org. As the movie demonstrates, coronal cavities do occur, and so the one you may have earlier in the week, whilst a great example of a coronal cavity, is definitely not unique. What is a coronal cavity? Let Dr. Alex Young of the The Sun Today tell you:
The material travels in to the field of view from its launch location, which can be seen in STEREO-B EUVI images. If you go to STEREO latest image selector and select ‘Behind EUVI 195’, pick a resolution of 512 x 512, type in a start and end date of 20120202, and select ‘Slideshow’, you get an animation of the event as seen from STEREO-B. There is a filament eruption on the upper left of the disk (it is hard to spot) which is the same material seen in the AIA 304 movie above:
Thanks to goggog67 for spotting this event and sharing it with us!
YouTube and users losyziemi, MeireRuiz7 and goggog67 have created a wonderful series of movies that show a flaring system of loops coming from a source active region just coming round the limb of the Sun. Thanks for sharing these great movies!
Solar flares are caused by the interaction of particles accelerated by magnetic reconnection with the surrounding plasma. In the movies below, you can see bright loop-top sources filling in their supporting loops. This caused by the flare-accelerated particles striking the surrounding plasma, and heating it up; as that plasma cools down, it appears in the AIA wavebands. This event should be visible in all the other AIA wavebands (which correspond approximately to different temperatures in the solar plasma).
The most recent LASCO, EIT, COR1/2 and EUVI images are currently unavailable to Helioviewer Project browse clients. This is because the computer that converts the science data to JPEG 2000 images experienced a mechanical failure on Friday January 13th. We will replace the failed machine, and make an announcement via the blog concerning the resumption of the availability of images from LASCO, EIT, COR1/2 and EUVI. We are apologize for any inconvenience this may cause. Finally, images from AIA and HMI should be unaffected.
Comet Lovejoy will be passing close to the Sun in the next couple of days. SDO will be taking special observations of the comet beginning 22:59 UT on 2011/12/15 (5.59pm 2011/12/15, Eastern Time), and lasting for a couple of hours. The comet will pass behind the solar limb at around 00:07 UT 2011/12/16 (7:07pm 2011/12/15, Eastern Time). There is a chance the comet will survive its encounter with the Sun.
SDO/AIA will take special observations to view the comet; AIA will change its pointing and point slightly away from the center of the Sun in order to try to get more observations of the comet as it gets close to the disk of the Sun.
Why are these observations being taken? Well, we are looking for something like we saw on 2011/07/05 this year. On that day a comet fell in to the Sun. These kinds of comets have been seen before in LASCO-C3 and LASCO-C2 images. What was new about this observation was that for the first time the comet was seen against the disk of the Sun. The video below gives a description of what was seen.
SDO/AIA detects different wavelengths of light. So in order for us to see it, the comet must have been emitting at those different wavelengths, and the comet must have disintegrated in to a big enough cloud of ionized gas for us to see it. So the big scientific question about seeing this comet against the disk of the Sun is explaining both how it came to be emitting at wavelengths that SDO/AIA could see, and figuring out how it could have disintegrated. This is an active area of research, with presentations on this subject given last week at the American Geophysical Union‘s Fall Meeting, and a paper set to appear in Science.
We hope you enjoy tracking Comet Lovejoy as it gets closer to the Sun. Please let us know if you have any further questions about the Helioviewer Project and Comet Lovejoy.
The filament(1) is the narrow dark moving thread in the middle of the field of view. As the movie progresses the filament evolves and eventually erupts out in to space, causing a coronal mass ejection. The material underneath the filament darkens, indicating an evacuation of plasma, that is, the plasma is draining away from that part of the solar atmosphere. These kinds of events happen a lot, and will happen more as solar activity ramps up. Thank you, muriealdurian, for uploading a good example of a filament eruption.
(1) Prominences are filaments seen over the limb of the Sun – prominences and filaments are the same thing, but have different names for historical reasons. Prominences and filaments were first observed in different wavelengths, and so acquired different names. Later, we realized that they were the same thing, but the two names have stuck around in the literature.
Helioviewer user otraLoly was first to share this rather spectacular looking event in SDO AIA data yesterday:
As the event progresses, you can clearly see that the material is spiraling around as it slowly moves away from the Sun’s surface. It may be associated with an ejection seen in LASCO C2, although the data here is as yet incomplete. Other users have also shred movies of the same event: here is one shared by danielchangck:
and another movie shared by papavalium:
If you find something interesting, please let us know by either emailing us at email@example.com, or by sharing it on helioviewer.org via YouTube.
We are very pleased to announce that Helioviewer Project services are now back online.
This means that Helioviewer.org, JHelioviewer, and other applications that use Helioviewer Project services are now available and should be working as before. If you encounter any problems with any of our services please let us know. We are currently filling in missing data from 2011/08/05 through to 2011/09/16, and we ask for your patience during the next couple of weeks as we fill in the gaps. If you notice any gaps, please let us know, as we are eager to have as complete a record of solar activity as possible.
We do apologize for the interruption in service. This was caused by two distinct and unfortunately simultaneous hardware malfunctions on our server that took a long time to repair. We are looking exploring options that will ensure such a long break in service does not happen again. We are back now, and we hope you continue to explore your heliosphere!
It’s a great example of the complex evolution that an active can undergo in a relatively short amount of time. Studying the evolution of active region loops on the limb cuts right through the loops themselves so you don’t see any of the disk emission along your line of sight, and so removes a potential source of confusion.
We apologize for the lack of new images from AIA. This is due to issues outwith our control. We create the images you see from AIA level 1.5 data products (the number refers to the degree of image calibration, etc., that has been applied to the raw data) that are processed at SDO Joint Science Operations Center. As you can see, those data appear to be lagging at the moment. As soon as the data returns, Helioviewer will automatically generate images and make them available.
Some of you may have noticed that helioviewer.org was not displaying recent AIA or HMI images in the last 24 hours. This was due to a glitch in the processing pipeline, and we apologize for this. The issue has been resolved and newer images are now coming online. We expect to be caught up within the next few hours. If you spot any problems, please let us know.
Helioviewer and YouTube user otraLoly spotted this interesting active region earlier on today.
Right at the very start you can see that loops on the southern side of the active region appear to contract (a CME and a prominence eruption are occuring). As the event progresses, you’ll notice that two dark areas appear in the coronal moss, outlined by some very bright, and small scale emission, which end up as loop footpoints to the subsequent loop brightening that occurs. This event is interesting for the detail it is possible to see in AIA, particularly in the brightening of the loop footpoints before the main bright loop occurs. Thanks to user otraLoly for sharing this video with users of helioviewer.org!
We are pleased to announce that the most recent, high quality STEREO images are now available on helioviewer.org.
First off, there are two spacecraft, called STEREO-A and STEREO-B. Both spacecraft orbit the Sun at roughly 1 AU (astronomical unit), or about as far away from Sun as the Earth is. However, STEREO-A is moving ahead of the Earth in its orbit, and STEREO-B is drifting behind the Earth in its orbit. This means that each STEREO spacecraft sees different parts of the Sun, parts that we can’t see from Earth. STEREO-B sees features on the Sun that we eventually see in SDO and SOHO, and STEREO-A allows us to see the continuing evolution of features that we did see in SDO and SOHO.
This plot shows where each spacecraft is now:
As you can see, they are quite far away from the Earth. This puts some operational constraints on each spacecraft that means we get high-quality images two days after they were taken. These are the data we are making available today; images from June 1st 2011, up to the most recently available data will be available initially. We ask for your patience, as we are uploading these images right now. Over the course of the next few weeks we will be making images from earlier in the mission available so that you can explore the Sun from many different angles over the past 4 1/2 years.
The benefit of seeing the Sun from many different angles is apparent when you look at the following three videos of the prominence eruption of June 7, 2011. The first one consists of images from SDO-AIA and SOHO-LASCO
We hope you enjoy these new images! As ever, please let us know if you spot any problems.
These videos show some of the larger scale effects of flares on the Sun. In the video, you can see two big eruptions approximately 10 and 17 seconds into the video, from the active region in the lower left.
But look more closely – can you see a wave of coming out of each of these explosions? They are faint, and can be difficult to see, but they are there. These are examples of EIT waves, so called because they were first seen in the SOHO–EIT instrument. These waves are thought to be examples of magnetohydrodynamic waves that propagate in the corona. They are truly large waves; for comparison, the radius of the Earth is about 1/100th that of the Sun. By studying these waves we can learn more about the structure and properties of the solar corona. There is also some evidence that these waves have ‘knock-on’ effects on other parts of the Sun, perhaps causing other events at parts distant from the original explosion. Look at the video – what do you think?