Archive for category User Highlights

User highlight: prominence motions

YouTube and Helioviewer.org user CuriousTess shared two two colour movie of a prominence coming over the solar limb. The first one shows the prominence at the solar limb:

and the second one shows the same feature further onto disk:

These movies show motions in a solar prominence. Prominences are clouds of relatively cool plasma magnetically suspended in the hotter surrounding solar atmosphere. By studying the motions and oscillations in a prominence, we can gain insight into their dynamic structure. A longer term research goal is to understand what makes some prominences unstable and erupt into space, while others don’t.

This image in the AIA 304 channel shows the same prominence:

2013_08_15_11_24_21_AIA_304

You can see from this picture that the prominence extends for a considerable distance, and appears to bend.

Thanks for sharing these movies, CuriousTess!

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Users highlights: spectacular prominences

Yesterday the Sun showed off a series of spectacular prominence eruptions that were recorded by many users.
Prominences are relatively cool, dense clouds of plasma that lie suspended in Sun’s magnetic field, sometimes for weeks. Occasionally, they become unstable and they erupt.

YouTube user 38starman posted these full disk movies of the Sun. The first is in AIA 304: this waveband sees plasma at around 50,000 K

and this is taken in PROBA2 173

It is possible that one event may have triggered another. Understanding the connection between separate events is a big part of Solar Dynamics Observatory science.

YouTube user коля павл posted a close-up of the prominence towards the south, this time in AIA 131

AIA 131 picks up temperatures at around 400,000 K, 10,000,000 K and 16,000,000 K. By looking at the AIA 304 images, it seems more likely that the prominence has plasma at around 50,000 and 400,000 K. The hotter temperatures that AIA 131 can see occur in flares, which are much more dynamic events than prominences. This is a good example demonstrating that the images we see can contain features at different temperatures.
Multiple wavebands really help us understand the true temperature of features on the Sun.

Thanks to 38starman and коля павл for sharing these movies!

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User highlight: oscillating coronal loop

YouTube and www.helioviewer.org user коля павл uploaded this great example of an oscillating coronal loop

As the movie progresses, you see a small eruption take place. As the eruption starts, you can clearly see the southern base of the loop displace. The loop appears to be released in some way, which shakes the whole loop along its entire length. This event is a great example of a transverse coronal loop oscillation. These were first observed by the Transition Region and Coronal Explorer (TRACE) in 1998. Since these initial observations, many more examples have been observed, by both TRACE and AIA. The mechanism of the excitation of these waves remains hidden, but it can be connected with a blast wave generated in a flare epicentre. For scale, the Earth is roughly the same size as the Helioviewer logo in the bottom right hand corner of the movie.

YouTube and www.helioviewer.org user Txema Mutant also caught the oscillation

although it is much more difficult to see in the AIA 193 Angstrom channel compared to the AIA 171 Angstrom channedl(the dark wavy material you see are motions in a prominence, not the same as the coronal loop oscillation).

Observations of coronal loop oscillations, coupled with a theoretical understanding of how these oscillations behave in the coronal plasma has lead to a new field of study called coronal seismology. Coronal seismology is analogous to seismology on Earth. Seismology is the study of earthquakes and the propagation of waves arising from earthquakes, and can be used to infer properties of the structure of the Earth. Similarly, coronal seismology is used to measure properties of the Sun’s coronal plasma. Using coronal seismology, we can derive the density and magnetic field of the coronal plasma, measurements that are difficult make in other ways.

Thanks to коля павл and Txema Mutant for sharing these movies!

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User highlight: Comet 96P/Machholz returns

YouTube and Helioviewer.org user otraLoly shared this short video of the return of Comet 96P/Machholz to the LASCO-C3 field of view. Thanks for sharing your video! More images of the comet will be available soon on Helioviewer.org.

The small, tadpole-like extended feature approximately in the center of the field of view in the image below is Comet 96P/Machholz.
Comet 96/PMachholz in 2012, close up

Comet 96P/Machholz has an orbital period of about 5.2 years, which means it has been seen before in LASCO observations. Here is an example image from 2007


Comet 96p/Machholz in 2007

and five years before that in 2002,


Comet 96p/Machholz in 2002

The dates for the entry of Comet 96P/Machholz were obtained from the transit page of the LASCO instrument. It is projected to be visible in the LASCO C3 field of view from July 12 – 17, and it may also be visible in the images from the STEREO A/B coronagraphs.

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User highlights: Transit of Venus in AIA

Here are some of the many excellent videos made by Helioviewer.org users of the Transit of Venus seen by AIA…

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User highlight: back-sided eruption appears to cause a front-sided eruption

Helioviewer.org and YouTube user danielchangck found this event:

What happened? Well, there was an eruption on the back side of the Sun, that caused a propagating disturbance in the solar atmosphere. that appears to have triggered a prominence lift-off on the front-side of the Sun. This is a great example of how the high cadence, continuous observations from Solar Dynamics Observatory give us a much better view of how distant parts of the Sun can physically influence each other. We liked this event so much we made and uploaded some movies of our own. The lower cadence of these movies allows you to see the swaying of coronal material in response to the disturbance from the initial eruption.

Thanks to danielchangck for sharing this movie with other users of Helioviewer.org.

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Spiralling eruption close to the south pole

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.

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Spotted: another coronal cavity

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:

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Eruption seen coming from the back of the Sun

YouTube and Helioviewer user goggog67 spotted this event that clearly happened on the other side of the Sun.

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:

and a flare in more or less the same area of the Sun – look for the very bright patch at the limb of the Sun at the upper left of the disk.

Thanks to goggog67 for spotting this event and sharing it with us!

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Coronal mass ejection and auroral activity, 24-25th January 2012

The coronal mass ejection associated with the flare event of 23 January 2012 has just been spotted by the Advanced Composition Explorer (ACE) spacecraft. ACE orbits the L1 libration point which is a point of Earth-Sun gravitational equilibrium about 1.5 million km from Earth and 148.5 million km from the Sun. From its location at L1 ACE has a prime view of the solar wind, interplanetary magnetic field and higher energy particles accelerated by the Sun, as well as particles accelerated in the heliosphere and the galactic regions beyond.

You can check here for recent observations of the distribution of the aurora borealis from space, courtesy of the NOAA Polar Operational Environmental Satellite. NOAA also have a test data product and webpage that shows the output of a model that predicts the probability of seeing the aurora. You can keep informed on the latest space weather activity at NOAA Space Weather Prediction Center and the Integrated Space Weather Laboratory.

Here are some more movies of the original event shared by our users – thanks to everyone!

YouTube and Helioviewer.org user losyziemi shared this video of the eruption and the consequent view in LASCO C2 and C3. Those streaks and dots are due to particles accelerated by the event impacting the detectors of LASCO C2 and C3

YouTube and Helioviewer.org user otraLoly shared this video of the eruption, concentrating on AIA 171 and LASCO C2.

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