Archive for category STEREO

Coming up: Comet ISON in November 2013

You may have heard of Comet ISON, a comet discovered last year that is currently approaching the Sun. It is expected to be visible in the SOHO-LASCO C2 and C3: from SOHO’s viewpoint the comet enters from the lower right early on November 27 and exits towards the top near the end of November 30 this year.

Path of COMET ISON as seen from SOHO

Path of COMET ISON as seen from SOHO LASCO C2 and C3 coronagraphs.

It will also be visible from the COR1 and COR2 instruments on board both STEREO spacecraft. The SOHO Hotshot webpage for Comet ISON has many more links to more details on the path of the comet as seen from SOHO and STEREO. At the moment it looks like this, as seen by the Hubble Space Telescope. It might be a spectacular sight from Earth. The appearance of comets from Earth is hard to predict because how it looks when it gets closer to the Sun depends on the details of its composition. We’ll have to wait and see!

Did you like this? Share it:


Helioviewer Server Technical Difficulties

We are currently experiencing some technical difficulties with our main Helioviewer server. While we work on fixing it, we have moved all services over to our backup server. All normal services should be operating nominally. Please contact us if you notice anything amiss with JHelioviewer services are currently not operational, but we hope to have these up and running as soon as possible. Near real-time AIA and HMI images should be available as usual; streams of images from SOHO, STEREO and PROBA2 should be back to near real-time within 24 hours.

We apologize for the interruption to Helioviewer services, and we thank you for your patience.

Did you like this? Share it:


Temporary delay in new AIA and HMI images

SDO AIA and HMI images are currently lagging behing real time by about 18 – 22 hours. This is due to some necessary hardware upgrades in the processing pipeline that have interrupted the flow of images. The availability of LASCO, EIT, COR1, COR2, EUVI and SWAP images is unaffected by these hardware upgrades. We expect that the lag in SDO AIA and HMI images compared to real time will be caught up in the next few hours. We apologize for the interruption in availability of near real time AIA and HMI images.

Did you like this? Share it:

No Comments

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!

Did you like this? Share it:


Recent LASCO, EIT, COR1/2 images available again

Recent images from the LASCO, EIT, COR1/2 instruments are now available again. We will be filling in the missing images over the coming days. We apologize for the interruption in providing these images.

Did you like this? Share it:


Interruption in LASCO, EIT, COR1/2, EUVI image availability

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.

Did you like this? Share it:

No Comments

Big Filament!

STEREO-B saw this big filament from its point of view looking over at back-side of the Sun.

The filament is the large dark straggly line of material in the upper left of the movie. Click here to see the movie in

Filaments are cool strands of material about 100 times cooler than the surrounding plasma, and are supported by magnetic fields. They can lie suspended but cool in the hot solar atmosphere for weeks, and then erupt in a matter of minutes, causing coronal mass ejections. It should be rotating into the SDO field of view in the next couple of days. If you are on Facebook, The Sun Today has a great post about this filament. Let’s see what happens!

Did you like this? Share it:


High quality STEREO images now available

We are pleased to announce that the most recent, high quality STEREO images are now available on

The STEREO (Solar TErrestrial RElations Observatory) mission is very different from the other missions (Solar Dynamics Observatory and SOHO) we feature on

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.

Did you like this? Share it:


Sneak peak at STEREO data…

We’re working on including data from NASA’s STEREO (Solar TErrestrial RElations Observatory, mission. It’s a mission consisting of two spacecraft, one drifting ahead of the Earth, and drifting behind, taking images of the Sun and the inner heliosphere. The concept behind the mission is to view the Sun as a three-dimensional object, from which we can better understand its surface structures and how it influences the inner heliosphere. This is the view from STEREO-A, and this is the view of the same event from STEREO-B. Both movies are of coronagraph data taken with the COR2 instrument; both STEREO spacecraft have the same instrument suites onboard.

We hope to have a stream of the very latest STEREO images very soon. Watch this space!

Did you like this? Share it:

No Comments