Friday, October 29, 2010

Notice: Website Outage. October 29-30, 2010

Notice: Website Outage.
When: October 29-30, 2010
Time: 6 pm - 4 pm

There will be a scheduled electrical outage in building 21 at Goddard Space Flight Center. Our web server will be shutdown from October 29, 2010 at 6 pm to October 30, 2010 at 4 pm.

Thursday, October 28, 2010

Spectacular Prominence Eruptions

Check out the latest 48 hour movies to see some spectacular prominence eruptions on both sides of the Sun! AIA 304 48 hour movie.

Wednesday, October 27, 2010

Kepler "asteroseismology" and SDO HMI "helioseismology"

The HMI instrument onboard SDO uses Helioseismology to look at "sunquakes" to determine some of the physical properties and motions inside our Sun. There is a great news release about the Kepler mission using a similar technique, Asteroseismology, to look at "starquakes" to determine similar characteristics of other stars. Both sets of observations will lead to significant advances about the evolution of stars, including our own, to better determine the activity cycles over short (years) and longer (hundreds and millions of years) time scales. Make sure to check out more about HMI at:

and also see the article at about Kepler at:

Tuesday, October 26, 2010

Maneuvers and Images

SDO is performing several instrument calibration maneuvers today. During these maneuvers the AIA boresight is being moved away from the center of the Sun. When the images are re-centered some of them have lines to the edges of the picture (such as we see in this 211 image). It appears that the re-centering of the images is copying the value at the edge of the field of view rather than zero while the image is being shifted to the center of the picture.

This will affect the rapid images shown on the SDO website and the LMSAL Sun Today website but will be corrected in the science database. However, information that is missing from images because the instrument is not pointed at the Sun cannot be recovered.

A lively active region

With a large active region currently in the northern hemisphere of the Sun, there has been a flurry of small solar flares over the past day. This larger active region may actually be comprised of four different active regions that are very close to each other forming one large, interconnected active region with multiple magnetic poles. This magnetically complex region has lead to 12 B-class and 1 C-class solar flare over the last 24 hours. Make sure to check out the daily and past 48-hour movies to see this rapidly evolving active region!

Friday, October 22, 2010

Notice: Website Outage. 10/21/2010 - 10/22/2010

Notice: Website Outage.
When: October 21 & 22, 2010
Time: 4:00pm - 11:00 am

There will be a scheduled electrical outage in building 21 at Goddard Space Flight Center. Our web server will be shutdown on October 21, 2010 at 4pm through October 22, 2010 at 11am.

Monday, October 18, 2010

The First LWS/SDO Workshop: "The Sun's Magnetic Activity Spectrum"

The dates have been set for the first SDO science workshop: May 2 - 6, 2011. The meeting will be held near Lake Tahoe, and the conference will highlight the science of all three SDO instruments: AIA, EVE and HMI. We encourage interested members of the science community to attend.

For more information, visit:

Thursday, October 14, 2010

HMI Roll Maneuver Complete, Antenna Handovers Continue

On October 12 SDO successfully performed a 7-hour roll maneuver to help calibrate the HMI instrument calibration. The spacecraft roll started at same time as HGA handover operation. This complicated the operational sequences but did not stop either maneuver.

While it is easy to point a space-based instrument at the center of the Sun it is more difficult to know the precise location of the Sun's rotation axis. Data from the roll maneuvers help the scientists to understand how their instrument response varies at different angles of the rotation axis. This is then used to more accurately remove the rotation effects from the data.

Sunday, October 10, 2010

A Southern Active Region, but No Southern Polar Coronal Hole?

As active region 11112 rotates into view we are seeing Solar Cycle 24 continue to increase in activity in both hemispheres. But why is there a dark hole in the Sun's north pole when we look at AIA 193 images but not in the south? These dark patches are called Polar Coronal Holes and are places where the Sun's magnetic field emerges from the Sun into the heliosphere.

They are best seen at solar minimum and disappear at solar maximum. But there may be a hole in the south that we can't see.

The Sun rotates on an axis that is tilted from the Earth's orbit by about 7 degrees. From August to October people watching the Sun from the Earth see the Sun's north pole and the Sun's south pole is invisible. From February to April we can see the south pole but not the north. To see if there is a southern polar coronal hole you need to look at the Sun from another position. We happen to have two STEREO spacecraft almost 90 degrees from the Earth doing just that. If you go to the STEREO webpage you will see there is still a southern polar coronal hole!