Sun

Sun activity: Geomagnetic storm expected. More red auroras?

Posted by
C. Alex Young
and
Raúl Cortés
and
Armando Caussade
and
September 26, 2023
Sun activity for September 26, 2023. NOAA forecasters anticipate a G1 (minor) geomagnetic storm for today, September 26. Conditions brought by the recent CME arrival still remain, so more geomagnetic disturbance is possible today. Are more red auroras coming? Image via NOAA.

Sun activity for September 26, 2023: Geomagnetic storm expected. More red auroras?

Today’s top news: A G1 (minor) geomagnetic storm is ongoing at the time of this writing, with more stormy conditions anticipated through the rest of the day. The G1 threshold was reached at 8:09 UTC this morning. With Earth’s magnetic field still feeling the effects of Sunday’s coronal mass ejection (CME) arrival, NOAA forecasters have issued an alert for auroral displays. Keep an eye out for more red auroras! And don’t forget to share your beautiful aurora photos with us.
Last 24 hours: Sun activity is back to low, but we saw filament eruptions all over the solar disk, particularly in the northeast and northwest. These filaments hurled ejecta into space, and we await the results of specialist analysis to determine if a component of those blasts is coming our way. Over the past day (11 UTC yesterday to 11 UTC today), only C class flares were produced – 18 in total. The largest was a C5.7 from the small but mighty sunspot region AR3445 at 4:28 UTC on September 26. AR3445 also became the lead flare producer of the past day, with ten of the 18 flares. AR3435 and AR3445 currently hold the potential for large flares, as they both show a delta magnetic complexity. The sun has nine numbered sunspot regions today, including two new kids in the neighborhood: AR3447 and AR3448.
Next 24 hours: Today’s forecast is a 99% chance for C flares, a 40% chance for M flares, and a 15% chance for X flares.
Next expected CME: No Earth-directed CMEs were observed in the available imagery.
Current geomagnetic activity: The Earth’s magnetic field is active with a G1 (minor) geomagnetic storm ongoing at the time of this writing (11 UTC on September 26). More G1 storms are expected today as the effects from Sunday’s CME arrival continue. Quiet to unsettled levels are expected tomorrow.

September 25, 2023. Sun activity is low, but we saw exploding filaments hurling ejecta into space, like this filament in the northwest, which fired off a coronal mass ejection (CME) after a faint explosion. GOES-16 SUVI 304 angstrom. Image via NOAA.
September 25, 2023. A large filament in the northeast quadrant exploded, hurling ejecta into space. The coronal mass ejection (CME) it fired is not coming our way at Earth. GOES-16 SUVI 304 angstrom. Image via NOAA.
The sun, seen as a large yellow sphere with dark spots, each labeled.
This image shows sun activity – with the most active regions labeled – as of 2 UTC on September 26, 2023. Original image, without labels, via NASA SDO. Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams, with labeling by EarthSky. Today’s sun is posted by Armando Caussade. Why are east and west on the sun reversed?

Sun activity for September 25, 2023: Surprise strong CME brings rare red aurora

What fun! Earth experienced a coronal mass ejection (CME) impact late yesterday (September 24, 2023). We’d expected a geomagnetic storm, but not a G3 (strong) storm. But G3 it was! And many in Europe and northernmost North America were surprised with the sight of a rare red aurora. In the aurora, red is created by oxygen in Earth’s atmosphere. This color is one of the more difficult ones to detect with the unaided eye because the human eye is less sensitive to red light. Many past reports of red auroras were associated with extreme magnetic storms. Last night’s storm wasn’t extreme, although it was strong. Why did people see this rare red aurora? We don’t know. But scientists will surely be looking today, trying to understand the conditions that led to these beautiful displays.
Last 24 hours: Over the past day (11 UTC yesterday to 11 UTC today), sun activity was moderate, due to a single M flare. In all, the sun released 18 flares, 13 of which came from yesterday’s hero, AR3445. This sunspot region – though small in size – is turning out to be the little engine that could! But AR3445 didn’t produce the largest flare of the past day. That was an M1 flare from AR3443 at 14:51 UTC on September 24, 2023. The M flare caused an R1 (minor) radio blackout over South America. AR3435 and AR3445 both show some magnetic complexity, with a delta region. The sun currently has nine numbered sunspot regions.

Red globe at the center surrounding by black disk, then red disk, the blue disk
Here’s the culprit that caused last night’s great auroral display. This image shows CMEs from September 22, 2023. The CME from the sun’s northeast is probably the one that impacted us last night (September 24). But some of the other CMEs might also have contributed. Images via SDO, SOHO, and jhelioviewer.

Sun activity for September 24, 2023: Meet sunspot region AR3445 (again)

We have a new kid in town! Well, not new exactly. Sunspot region AR3445 rotated onto the Earth-facing disk of our star a few days ago. It gained a delta region (a possible indication of strong flaring), and it produced a two big flares. Then it went away. Now it has came back! And now it has kicked into high gear and produced a lot of flaring. It produced 15 of the 21 solar flares of the past day. That’s including three of the past day’s four M flares, plus the largest event of the period, an M4.4. AR3445 is far from being the biggest spot region on the sun. It’s little, but mighty! And there’s more news. We might see more auroral activity into the coming week, due to the influence of a coronal hole and the possible arrival of CMEs today and September 26. Read more below, and stay tuned!
Last 24 hours: Sun activity continues at a moderate levels thanks to four M flares during the past day (11 UTC yesterday to 11 UTC today). The sun released a total of 21 flares, 15 of which came from AR3445. This region produced the largest event, an M4.4 flare and two of the other M flares. Each M flare caused an R1 (minor) radio blackout. The breakdown of the M flares and R1 blackouts of the period is:
– M1.6 by AR3446 at 20:14 UTC on September 23. R1 (minor) radio blackout over the Pacific.
– M1.2 by AR3445 at 02:51 UTC on September 24. R1 (minor) radio blackout over Australia.
– M1.9 by AR3445 at 03:09 UTC on September 24. R1 (minor) radio blackout over Australia.
– M4.4 by AR3445 at 03:17 UTC on September 24. The largest of the four, it produced an R1 (minor) radio blackout over Australia.
By the way, the M4.4 was a long-duration event, though it appeared more as a set of smaller flares combined together rather than a single long event. If, like many long duration events, it produced a coronal mass ejection (CME), the region’s position makes it ideal for sending that CME towards us. We await further analysis to know the final outcome. In the meantime, also in the past day, AR3443 gained a delta region. And AR3441 now has a slightly less complex, beta-gamma, magnetic configuration. None of the regions are particularly large, so we’ll see what happens next. The sun currently has 11 numbered sunspot regions.

The bottom left quarter of a gold and purple globe.
Sun activity for September 24, 2023. Sunspot AR3445 has picked up activity over the past day. Here’s an M4.4 solar flare (the bright area near the center of this image), the biggest flare of the past day. This sunspot region produced most of the other flares during the past day, too. Images via SDO and jhelioviewer
Grid of four images all animated rotating left to right. The colors are red, gold, pink, and teal.
Sun activity for September 23-24, 2023. This animation show the 24 hour observation period of the September 24, 2023 sun activity post. From left to right and top to bottom are shown the 304, 171, 211, and 131 angstrom SDO channels respectively. Images via SDO and jhelioviewer

The sun in recent days

The sun, seen as a large yellow sphere with dark spots, each labeled.
This image shows sun activity – with the most active regions labeled – as of 3 UTC on September 25, 2023. Courtesy of NASA/ SDO and the AIA, EVE, and HMI science teams, with labeling by EarthSky.
The sun, seen as a large yellow sphere with dark spots, each labeled.
This image shows sun activity – with the most active regions labeled – as of 1 UTC on September 24, 2023. Courtesy of NASA/ SDO and the AIA, EVE, and HMI science teams, with labeling by EarthSky.
The sun, seen as a large yellow sphere with dark spots, each labeled.
This image shows sun activity – with the most active regions labeled – as of 7 UTC on September 23, 2023. Courtesy of NASA/ SDO and the AIA, EVE, and HMI science teams, with labeling by EarthSky.
The sun, seen as a large yellow sphere with dark spots, each labeled.
This image shows sun activity – with the most active regions labeled – as of 0 UTC on September 22, 2023. Courtesy of NASA/ SDO and the AIA, EVE, and HMI science teams, with labeling by EarthSky.
The sun, seen as a large yellow sphere with dark spots, each labeled.
This image shows sun activity – with the most active regions labeled – as of 0 UTC on September 21, 2023. Courtesy of NASA/ SDO and the AIA, EVE, and HMI science teams, with labeling by EarthSky.
The sun, seen as a large yellow sphere with dark spots, each labeled.
This image shows sun activity – with the most active regions labeled – as of 1 UTC on September 20, 2023. Courtesy of NASA/ SDO and the AIA, EVE, and HMI science teams, with labeling by EarthSky.
The sun, seen as a large yellow sphere with dark spots, each labeled.
This image shows sun activity – with the most active regions labeled – as of 3 UTC on September 19, 2023. Courtesy of NASA/ SDO and the AIA, EVE, and HMI science teams, with labeling by EarthSky.

Sun images from our community

We invite you all to send us your beautiful recent photos of sunspots and auroras. Naturally, we love receiving your photos! And to those of you who’ve already posted a photo to our community page, thank you.

Submit photos here

View community photos here

The sun, seen as a large white sphere with small dark spots.
View at EarthSky Community Photos. | Patricio León in Santiago, Chile, captured this filtered image of the sun on September 25, 2023. Patricio wrote: “Big sunspots groups look sharper. A new one appeared below left of AR3445, and other spot is just rotating the upper eastern limb.” Thank you, Patricio!
A collage of two large sunspots, side-by-side, shown in black and white.
View at EarthSky Community Photos. | David Hoskin in Halifax, Nova Scotia, Canada, captured these filtered close-ups of the sun on September 22, 2023. David wrote: “Broadband (left) and hydrogen-alpha (right) filtered images of sunspot group AR3435, which unleashed a very strong M8-class solar flare on 20 September 2023.” Thank you, David!
The sun, seen as a large yellow sphere with a mottled surface.
View at EarthSky Community Photos. | Mario Rana in Hampton, Virginia, captured this filtered image on September 20, 2023. Mario wrote: “Hydrogen-alpha image of the sun featuring active region AR3435. Nice prominence on the northwest limb!” Thank you, Mario!
The sun, seen as a large yellow sphere with a mottled surface.
View at EarthSky Community Photos. | Jim Militello in Tucson, Arizona, captured this hydrogen-alpha filtered image of the sun on September 19, 2023. Jim wrote: “The image shows active regions 3435, 3436, & 3437 with sunspots and numerous prominence.” Thank you, Jim!
The sun, seen as a sectional orange sphere with a mottled surface.
View at EarthSky Community Photos. | Mike Ducak in Guelph, Ontario, Canada, captured this hydrogen-alpha filtered image of the sun on September 16, 2023. Mike wrote: “Went out for a quick peek at the sun and found this gigantic prominence, one of the largest and most intricate I’ve ever seen. Managed to get this quick capture during a break in the clouds. Solar observing isn’t for everyone, but I love how it can surprise you.” Thank you, Mike!

Bottom line: Sun activity for September 26 is low, with C flares only. The recent CME impact continues to provoke geomagnetic storming. More auroras could be on the way!

Posted 
September 26, 2023
 in 
Sun

C. Alex Young

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About the Author:
C. Alex Young is a solar astrophysicist studying the Sun and space weather. Alex is passionate about sharing science with diverse audiences. This led him to start The Sun Today with his designer wife, Linda. First through Facebook and Twitter then adding an extensive website thesuntoday.org, the two work together to engage the public about the Sun and its role in our solar system. Alex led national engagement efforts for the 2017 total solar eclipse. He is the Associate Director for Science in the Heliophysics Science Division at NASA Goddard Space Flight Center.

Raúl Cortés

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About the Author:
Raúl Cortés studied engineering at the Autonomous University of Nuevo León in Monterrey, Mexico, obtained a scholarship to continue his studies in Japan and after returning to Monterrey he got credits on MBA from the Graduate School of Mechanical and Electrical Engineering Faculty. He became a teacher at the University UANL teaching Math and Physics and dedicated the rest of his professional career to serve in engineering areas for USA, Japan and Germany based corporations. His passion for the skies go back to when he was a child, always intrigued about the stars and constellations and reading and researching about the matter. From 2010 on, he dedicated his attention to photographing the stars, constellations, the moon and the sun. Raúl's work on his photography has been published and posted on the ESC as well as in other platforms and has gained attention to be published by local Monterrey newspapers.

Armando Caussade

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About the Author:
Armando is well known as an astronomy educator, after 30+ years leading extensive initiatives of public outreach and 10+ years teaching in colleges. As one of only a handful of Puerto Rican science communicators during Comet Halley's last visit, he assumed a pioneering role starting in 1985 when science was just beginning to enter the local mindset; over time his work brought meaningful change to the culture, inspiring people to pursue interests in science and technology. His affiliations include Ana G. Méndez University–Cupey, where in 2014 he spearheaded an 8-course extension program focusing on observational astronomy, the first ever in the island.

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