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!

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!

Happy Summer Solstice 2018!

Today, June 21, 2018, at 1007 UTC (6:07 am ET) the Sun reached its northernmost point in our sky. In the northern hemisphere we have the longest day of the year while people in the southern hemisphere have their longest night. Six months from now we will reverse places for the Winter Solstice. It's all due to the tilt of the Earth's rotation axis that tilts us toward the Sun in northern summer. Our ancestors often celebrated the Solstices with parties. I'll celebrate with some pictures of the Sun.

For those who thought Solar Cycle 24 had faded into history, please look at today's Sun. There are three active regions visible on the Sun and a sunspot number of 52. This blended image overlays an HMI magnetogram with an HMI continuum image. Helioviewer.org has provided pointers to the active regions. (The little β describes the complexity of the active region.) All three regions are at low latitudes in the northern hemisphere of the Sun and have the black magnetic field leading the white, so they are Solar Cycle 24 sunspots. Another region of Solar Cycle 24 field is visible on the left and will soon rotate into view.

Even as Solar Cycle 24 fades, we see the signs of the next cycle. Here is an AIA 171 Å image, also with the active regions pointed out. I added two arrows to the dark patches at the poles of the Sun. Those polar coronal holes contain the seeds of Solar Cycle 25. The strength of the polar magnetic field says that Solar Cycle 25 will be a little more active than Solar Cycle 24. We only have to wait until 2025 to find out.

Thanks to Helioviewer.org for the labels.

Enjoy the Solstice!