Celebrate the Winter Solstice at 11:59 am ET today!

Today is the Winter Solstice. The length of daylight is the shortest of the year in the Northen hemisphere and the longest in the Southern. For the Northern hemisphere it corresponds to the beginning of the cold winter season while people in the Southern hemisphere are starting to enjoy their summer time weather.
The occurrence and timing of solstices was known to many early cultures, from Mesopotamia to Mesoamerica. It was a time to celebrate when the Sun stopped moving southward and began moving back to bring warm to their homes. We know that the tilt of the Earth's rotation axis causes the seasons but we continue to celebrate their changes.

Enjoy the Winter Solstice!

Momentum Management Maneuver #42, December 15

SDO executed momentum management (MM) maneuver #42 on December 15 from 1945-2015 UTC (2:45-3:15 pm ET). During an MM maneuver SDO science data may be missing or blurred. These maneuvers are needed to keep SDO accurately pointed at the Sun and taking data.

X-class flare at 1555 UTC (11:55 am ET)

Active region 12887 emitted an X-class flare today at 1555 UTC. There also appears to be a filament eruption (the precursor to a coronal mass ejection). This is the second X-class flare of Solar Cycle 25 (the first was on July 3, 2021.)

Before the flare a filament cam be seen over AR 12887 (in the blue circle).

The flare begins to brighten up at 1529 UTC.

The filament liftoff from the surface can be seen as the dark region a litle to the left of the flare in the third image.

The flare continues to brighten until its peak flux. Check out the flare in the Browse AIA/HMI Images at the SDO website.
Solar Cycle 25 is alive and well!

October 2021 Instrument Calibration Maneuvers have Finished

The October 2021 Instrument Calibration maneuvers have finished. During an instrument calibration maneuver SDO science data may be missing, blurry, or misaligned. The first two cannot be corrected but roll angle is no longer seen as a rotation of the solar image.

• 13 Oct 2021: EVE Cruciform, 1400–1852 UTC (10:00 am - 2:52 pm ET)
• 20 Oct 2021: HMI Roll Maneuver, 1400-2040 UTC (10:00 am - 4:40 pm ET)
• 27 Oct 2021: EVE FOV and HMI/AIA Flatfield Calibrations (EVE FOV @ 1315 UTC; HMI/AIA Flatfield @ 1630 UTC)

The next set of calibration maneuvers will be in January 2022 (EVE Cruciform, EVE FOV, and HMI/AIA Flatfield) and April 2022 (HMI Roll).

Momentum Management Maneuver #41 today

SDO will execute momentum management (MM) maneuver #41 today from 1820-1840 UTC (2:20-2:40 pm ET). During an MM maneuver SDO science data may be missing or blurred. These maneuvers are needed to keep SDO accurately pointed at the Sun and taking data.

Congratulations to the EVE Team!

NASA 36.353 sounding rocket flight to calibrate SDO EVE and several other satellite instruments was a great success. Hre's the proof, exposures from both the MEGS-A and MEGS-B CCDs in the calibration EVE. The top image is from the MEGS-A CCD with MEGS-A1 spectrum on top and MEGS-A2 spectrum and MEGS-SAM X-ray image on the bottom. The bottom CCD image is the MEGS-B spectrum that goes diagonally across the CCD. The bright (yellow and red) vertical stripes are the spectral lines of the Sun that EVE studies. Just seeing these spectral lines means our Sun has a magnetic field. Without the magnetic field this part of the spectrum would be empty.

I can't wait to see the movie.

Congratulations to the EVE for a successful flight!

EVE Calibration Rocket Flies over WSMR Today

Today the EVE Calibration Rocket will fly above White Sands Missile Range (WSMR) near Las Cruces, NM. The launch window opens at 11:25 am MT (1:25 pm ET) and closes at 12:05 pm MT (2:05 pm ET). The EVE team is watching the Sun. The goal is to measure the quiet Sun and any significant flare will delay the launch until the effects of the flare fade. After parachuting to the ground, Rocket EVE will be re-calibrated at NIST's SURF in Maryland.

These calibration rockets are needed to track the changes in the EVE and AIA instruments that have been in orbit for over 11 years. Instruments that measure the extreme ultraviolet are extremely sensitive to contamination. Even small amounts of hydrocarbons (such as Teflon) landing on the CCDs inside the instruments can reduce the amount of light reaching the pixels. Comparing the data from the instruments in space with the data from the “clean” calibration instrument gives the correction factor we need.

Check out the LASP news release for more information.

Here's to a great launch and successful recovery!

Station Keeping maneuver #23, August 4, 2021

SDO will execute Station Keeping maneuver #23 today from 2230-2314 UTC (6:30-7:14 pm ET). During a maneuver SDO science data may be missing or blurred. These maneuvers are needed to maintain SDO's assigned position as it passes through the geostationary orbit belt.

EVE FOV and HMI/AIA Flatfield calibration maneuvers, July 21, 2021

SDO will execute EVE FOV and HMI/AIA Flafield maneuvers today. The maneuver should take about 4 hours. During a maneuver SDO science data may be missing or blurred. These maneuvers are needed to keep the instruments accurately nmeasuring solar data.

EVE Cruciform Maneuver, July 14, 2021

SDO will execute an EVE Cruciform maneuver. The maneuver should take about 6 hours. During a maneuver SDO science data may be missing or blurred. These maneuvers are needed to keep EVE accurately nmeasuring the solar EUV spectral irradiance.

Some Fireworks over the Weekend!

At 1430 UTC (10:30 am ET) on July 3, 2021, the first X-class flare (actually an X1.5 flare) of Solar Cycle 25 was seen on the Sun.

There were also several B and C flares, and even one M flare in the day before the X1.5 flare. You can see this series near the limb in the upper right (a clock position of about 2:00) in this daily movie in SDO's AIA 94 Å passband. These flares were also seen in the EVE on SDO and the XRS on GOES-16.

There was no active region associated with the X1.5 flare. A large region of magnetic field that was rotating off the disk is probably the home of the flares.

Solar Cycle 25 is starting to get more interesting!

Coronal Loops are Nice to Look At!

As Solar Cycle 25 starts becoming more active, coronal loops have become more common and beautiful. Here is a movie from June 24, 2021, showing the decaying remnants of AR 12833 rotating off the Sun in the upper right and the just-forming AR 12835 rotating into view in the lower left. You can see small filaments in and around the two active regions, with a very nice filament liftoff in the area following AR 12833.
There are many filaments visible around the limb of the Sun. In the lower left, around 7:30, you can see what looks like a coronal cavity (a filament surrounded by a dark, more-or-less circular, region.

Solar Cycle 25 is looking good!

SDO Stamps are on Sale!

USPS Forever stamps featuring SDO images were released by the Post Office on Friday in a ceremony at the Greenbelt, Maryland, Post Office. The stamps have 10 SDO images in each set:

The Summer Solstice (Northen Hemisphere) occurred at 11:32 pm ET yesterday (June 20, 2021). Celebrate the solstice with SDO Stamps. Send someone the Sun!

Guidance System Calibrations Yesterday

Yesterday, June 16, 2021, from 1700-2000 UTC (1-4pm ET), SDO ran calibration maneuvers for the pointing system. These tests were to restart one of the inertial reference units and then a roll of the satellite to help refine some of the parameters in the Kalman filter. During this time science data may be missing or blurry. The tests were successful and will help maintain SDO's pointing accuracy for years to come.

My congratulations to the Flight Operations Team for completing an excellent set of calibration maneuvers!

A Week of Infrastructure Repairs!

This week is a busy week for people making repairs of SDO-related infrastructure.

On Tuesday, 8 June 2021, the fiber optics linking the SDO ground station and the SDO JSOC in Palo Alto, CA, will be disconnected and relocated. This work is scheduled to start at noon MT and to take about 2 hours but could last as long as 6 hours. During this time the AIA and HMI data will be unavailable. The automatic replay option will fill in the data once the repairs are complete.

The NASA building housing the SDO servers will undergo infrastructure maintenance 12-13 June 2021. This will require us to shutdown our servers over that weekend, which means the website and data will not be available. The servers will be powered down Friday evening (June 11, 5 pm ET) and powered up Monday morning (June 14).

We apologize in advance for any inconvenience these repairs may cause.

Momentum Management Maneuver #40 Today

SDO will execute momentum management maneuver (MM) #40 today starting at 1910 UTC (2:10 pm ET). The maneuver should take about 30 minutes. During a maneuver SDO science data may be missing or blurred. These maneuvers are needed to keep SDO accurately pointed at the Sun and taking data.

SDO Off-Point during the Parker Solar Probe Perihelion

From 2100 UTC (5:00 pm ET) on April 28, 2021, to 1100 UTC (7:00 am ET) on April 29, 2021, SDO will off-point from the center of the Sun. This will support the PSP perihelion passage at 0900 UTC, April 29, 2021.

This is an opportunity for you to examine the middle corona that is not normally seen in the AIA field-of view. The exposure time will be increased, there will be fewer AIA images, and lossless compression will be used to download the images. That means you will be able to bring out details in the middle corona by co-adding frames.

Website Maintenance - April 27, 2021

The SDO website is undergoing some maintenance today, April 27, 2021. Some site features and pages will be unavailable during this time. We apologize for the inconvenience. 

EVE Cruciform Maneuver Today

SDO will perform the EVE Cruciform Calibration Maneuver today from 1300 UTC (9:00 am ET). During the maneuver science data may be missing or blurred.

Celebrating A Solar Cycle of Discovery with SDO

You are Invited to Contribute your Solar Research to a Topical Collection of Solar Physics on “Celebrating A Solar Cycle of Discovery with SDO”

 

We solicit manuscripts on this general subject for inclusion in a Topical Collection of Solar Physics.  The deadline for submission of statements of interest (SOI) with a tentative title, abstract, author list, and three suggestions for referees, via e-mail to solar.cycle.with.sdo@gmail.com is 15 June 2021, and the nominal deadline for manuscript submission is 22 October 2021.

This Topical Collection is an outgrowth of the “SDO 2021 Science Workshop: A Solar Cycle of Discovery,” which was held as a series of virtual workshops 12 February – 15 April 2021 (http://sdo2021.lws-sdo-workshops.org). This Topical Collection is not a conference proceeding, and it is not limited to research presented at the workshop. All submissions must be complete original papers that meet the regular quality requirements of the Journal. The Topical Collection will start off with several invited reviews to summarize the subject and frame the work in the research papers which follow. Please consult https://link.springer.com/journal/volumesAndIssues/11207?tabName=topicalCollections for recent Topical Collections.

Topics to be included in the Topical Collection include:

·         Subsurface Flows, the Dynamo, and the Solar Cycle

·         Magnetic Flux in the SDO Era: From Emergence to Eruption

·         Vector Magnetic Field: Progress and Prospects

·         Energy and Mass Transfer Between the Corona and the Chromosphere

·         Short-term Solar Variability

·         Phun with Photons: Response of atmospheres to EUV variability

·         The SDO Corona and Beyond

·         SDO for Space Weather: Science and Applications

For further information, and submission of statements of intent, please contact John Leibacher (Solar Physics editor: john.leibacher.sola@gmail.com) or Dean Pesnell (guest editor), Ryan Milligan (guest editor), and Shin Toriumi (guest editor) at solar.cycle.with.sdo@gmail.com.

Calibration Maneuvers Today

SDO will execute two calibration maneuvers on April 7, 2021. The EVE Field of View (FOV) maneuver will begin at 1315 UTC (8:15 am ET). The HMI/AIA Flatfield maneuver will begin at 1630 UTC (11:30 am ET). During a calibration manuever the SDO science data may be missing or blurred. HMI science data is only available when SDO is in Sun-pointing mode.

Here is an AIA 171 Å picture from today's maneuver. The straight edges on the left and top show that SDO is pointed slightly away from Sun center. The image is re-centered by the processing software.

Happy 11th Birthday to SDO

SDO was launched 11 years ago on February 11, 2010. It was a beautiful launch into mostly clear skies over the Kennedy Space Center in Florida. SDO has watched almost all of Solar Cycle 24, and now the beginning of Solar Cycle 25. Scientists have used SDO data to publish over 5000 papers on how the Sun works, emphasizing the creation and destruction of the solar magnetic field. Here's a movie of the Sun in AIA's 193 Å passband on February 11, 2021, showing a large filament (dark line in the southern hemisphere) just outside of a dark coronal hole. There's a bright region to the left of the filament that sits over a magnetic field concentration that never formed a sunspot. It looks like Solar Cycle 25 will be as much fun as SC 24!

Station Keeping Maneuver # 22 on February 10, 2021

SDO will perform Station Keeping maneuver #22 on Wednesday, February 10, 2021, at 1737 UT (12:37 pn ET) and lasting about 30 minutes. During the maneuver science data may be blurred or missing. This maneuver keeps SDO inside its assigned box as it passes through the geostationary belt.

SDO Images will be on US Stamps in June!

According to this NASA News Release, SDO images will be featured on a set of USPS First Class Forever stamps. Here's what the stamps will look like.

SDO's 100's of millions of images of the Sun’s dynamic and dazzling beauty have captivated millions of people. Near the summer solstice of 2021 you should be able to use these select 10 as beautiful stamps. Watch for them!

Tomorrow is the First SDO Lunar Transit of 2021

January 13, 2021, will see the Moon pass across the face of the Sun between 0556 and 0625 UTC (00:56 and 1:25 am ET). Here's a movie of the transit from the SDO Flight Operations Team.

This transit occurs while SDO is near the midnight sector of its orbit. That means the motions of the Moon and SDO combine to make this a short transit, lasting only about 30 minutes.

Enjoy!

Winter Calibration Maneuvers, January 6, 2021

SDO will execute two calibration maneuvers on January 6, 2021. The EVE Field of View (FOV) maneuver will begin at 1315 UTC (8:15 am ET). The HMI/AIA Flatfield maneuver will begin at 1630 UTC (11:30 am ET). During a calibration manuever the SDO science data may be missing or blurred.

It's Perihelion Day!

Today at 8:50 am ET (1350 UTC) the distance between the Earth and Sun was the smallest it will be this year (perihelion). On July 4, 2020, we were the furthest from the Sun (aphelion). Here is a picture comparing the Sun as seen by HMI on those two days.

The left half shows what the Sun looked last July. The right half is an image from today. The Sun appears a little larger today because of our elliptical orbit around the Sun. This difference also means the telescopes on SDO were designed to fit the Sun at perihelion into the images. I made this from the images on the SDO website. You can make one yourself using the other wavelengths available there.

For every minimum distance of an orbit there is also a maximum distance. For the Earth and Sun this is called aphelion and will next occur on July 5, 2021 6:27 pm ET (2200 UTC).

Welcome to 2021!

SDO was recently told we were renewed for another three years of operations. This will take us well into the rising phase of Solar Cycle 25. I would like to thank all of the people who helped write the Senior Review proposal to keep SDO operating.

Here is a excellent example of the beginning of Solar Cycle 25. This AIA 193 Å movie shows a solar disk with coronal holes, filaments, and a lovely coronal cavity above the limb at 7 o'clock. You can see the filament as the dark lines betwee the cavity and the surface. We should see more cavitites as the polar crown filament continues to form.

Have a prosperous 2021!