National Solar Observatory

10/20/2026

Solar Activity Report: October 12-18, 2026

Solar activity remained predominantly at low levels throughout the reporting period, except on October 16, when activity briefly reached moderate levels following an M1.3 flare from active region 14551, the largest event of the week. During the remainder of the period, activity was characterized by persistent C-class flaring, including several mid intensity C-class events. By the end of the week, most active regions had rotated into the western hemisphere, leaving the eastern hemisphere largely devoid of sunspots. No Earth-directed coronal mass ejections (CMEs) were observed.

Current helioseismic far-side maps do not reveal any major active regions that are expected to emerge onto the Earth-facing hemisphere within the next few days.

Data by NSF-NOAA GONG, operated by NSF NSO.

Additional Credits: Jain/Oien/NSF/GONG/NSO/AURA, with contributions by NOAA

10/13/2026

Solar Activity Report: October 5-11, 2026

Solar activity varied substantially during the reporting period, rising from low to high and then returning to low levels. Such variability is typical of the declining phase of the solar cycle, when sudden bursts of enhanced activity are common. Approximately 50 C‑class and 7 M‑class flares were observed, with most originating from active region 14549. The strongest event was an M6.7 flare on October 8 from this region, followed by another high‑energy M6.4 flare on October 10.

Other M‑class flares were of lower intensity: an impulsive M1.0 flare from active region 14545 on October 5; M1.4 and M1.8 flares from active region 14549 on October 6; an M1.3 flare from active region 14547 on October 9; and an M1.2 flare from active region 14549 on October 10. All of these active regions were located in the northern hemisphere, which was more active than the southern hemisphere during this period. The X‑ray flux remained near the B/C‑level boundary. The quietest day of the week was October 11, when the flux stayed predominantly in the B‑level. Several CMEs were originated from these flares, some with Earth‑directed components.

Data by NSF-NOAA GONG, operated by NSF NSO.

Additional Credits: Jain/Oien/NSF/GONG/NSO/AURA, with contributions by NOAA

10/07/2026

A multi-agency team from the U.S. National Science Foundation (NSF) National Solar Observatory (NSO), NASA, and the U.S. Naval Research Laboratory has received NASA’s 2026 Center Excellence in Group Achievement award for creating "CHAR."

This revolutionary methodology feeds surface observations from solar telescopes directly into ongoing 3D simulations of the Sun's atmosphere. By accurately reproducing the buildup and onset of solar eruptions using only surface data, CHAR is enabling a new era of reliable space weather forecasting.

Read the full story on our website to dive into the science with NSO lead author Dr. Lucas Tarr below.

A multi-agency team won a 2026 NASA award for CHAR, a revolutionary methodology enabling a new era of reliable 3D space weather forecasting.

10/06/2026

Solar Activity Report: September 28-October 4, 2026

As the solar cycle continues its declining phase, magnetic activity has decreased significantly. Solar activity remained at very‑low to low levels throughout the reporting period. A few low‑intensity C‑class flares occurred during the first two days, followed by an increase in X‑ray flux on September 30 when Active Region 14535 produced the strongest event of the week: an impulsive C8.6 flare. October 2–3 were the quietest days of the period. No Earth‑directed CMEs were observed.

Current helioseismic map of the far side indicates no significant active regions poised to rotate onto the visible disk in the next few days. A few small regions, however, may turn toward Earth toward the end of the week.

Data by NSF-NOAA GONG, operated by NSF NSO.

Additional Credits: Jain/Oien/NSF/GONG/NSO/AURA, with contributions by NOAA

10/01/2026

How do you maintain a stable environment at the world’s largest solar observatory? ☀️

Two technical papers from the NSF National Solar Observatory engineering team highlight the evolution and recent updates to the Facility Thermal Systems (FTS) and Facility Maintenance System at the NSF Daniel K. Inouye Solar Telescope.

Managing heat is one of the observatory's greatest hurdles, as even minor temperature shifts can blur images of the Sun. To combat this, the FTS uses a sophisticated network of seven miles of piping and 11 independent cooling loops.

Thanks to a recent engineering review and smart automation upgrades, the system is poised to be more energy-efficient and reliable, ensuring clear, high-resolution solar observations for years to come.

Brialyn Onodera, NSO Senior Mechanical Engineer, and Chris Foster, NSO Thermal Systems Engineer presented these findings at the SPIE Astronomical Telescopes + Instrumentation conference in Copenhagen, Denmark. 🇩🇰

Read the full update: https://nso.edu/blog/taming-the-sun-an-update-on-the-massive-cooling-network-of-the-nsf-inouye-solar-telescope/

Learn how recent engineering upgrades to the Inouye Solar Telescope cooling system improve efficiency, reliability, and image quality.

09/29/2026

Solar Activity Report: September 21-27, 2026

Solar activity remained at low levels during the reporting period, with X‑ray flux generally at mid‑B levels except for a few impulsive low C‑class flares. Several active regions were present on the visible disk, but most remained relatively quiet, producing little to no significant flaring activity aside from occasional low‑intensity C‑class events. The strongest flare was an impulsive C3.1 event on September 26 from active region 14534. No Earth‑directed CMEs were identified in available coronagraph imagery.

The most recent helioseismic map of the far side shows no evidence of significant active regions that are likely to rotate onto the Earth‑facing hemisphere over the next few days.

Data by NSF-NOAA GONG, operated by NSF NSO.
Additional Credits: Jain/Oien/NSF/GONG/NSO/AURA, with contributions by NOAA

09/25/2026

What can a nearly 300-year-old solar eclipse teach us about the Sun today? ☀️🔭

NSF National Solar Observatory Associate Director Alexei Pevtsov recently co-authored a new paper analyzing 18th-century eclipse observations, highlighting why preserving historical data is crucial for studying long-term solar activity.

Read about the research in this new AAS Nova feature below.

Handwritten eclipse observations from 1733 offer researchers a rare window into a data-poor period of solar history.

09/23/2026

Solar Activity Report: September 14-20, 2026

Solar activity during the reporting period remained in the very‑low to low range. At the beginning of the week, all named active regions were clustered in the western hemisphere, leaving the eastern hemisphere without sunspots.

Around September 19, new active regions began to appear on the east limb, raising the activity level into the low category. Active region 14535, rotating into the Earth‑facing hemisphere, produced the first C‑class flare of the week (C3.3) along with a few additional low‑intensity C‑class flares.

In addition, active region 14534 generated the strongest event of the week, a C3.7 flare, while positioned near the central meridian in the northern hemisphere. No Earth‑directed CMEs were observed.

Helioseismic imaging of the Sun’s invisible hemisphere shows no evidence of any major active regions expected to rotate onto the visible disk in the coming week.

Data by NSF-NOAA GONG, operated by NSF NSO.
Additional Credits: Jain/Oien/NSF/GONG/NSO/AURA, with contributions by NOAA

09/15/2026

☀️Solar Activity Report: September 7-13, 2026

The current solar cycle is now in its declining phase, and high‑energy flares have decreased substantially.

Over the past week, the X‑ray flux level did not exceed the C category, with the strongest event being a C5.8 flare on September 12. This region produced most of the C‑class activity, accounting for six of the 15 observed flares.

Activity briefly dropped to very low levels on September 11 when the X‑ray flux remained in the B category. A total of four CMEs were detected, none with a significant Earth‑directed component. A glancing impact is possible on September 17 from the CME associated with the long‑duration C1.4 flare on September 13.

Far‑side helioseismic maps do not indicate the emergence of any new major active regions rotating into Earth’s view.

Data by NSF-NOAA GONG, operated by NSF NSO.
Additional Credits: Jain/Oien/NSF/GONG/NSO/AURA, with contributions by NOAA

09/13/2026

☀️ The NSO celebrates a summer of science!

This summer, college students in Hawai‘i and Colorado got hands-on experience in cutting-edge solar science and engineering with mentors from the NSF National Solar Observatory.

From the NSF Daniel K. Inouye Solar Telescope in Maui to Boulder’s space physics community, students tackled real-world research, presented their findings, and took another leap toward careers in STEM.

The NSO is a longstanding and proud partner in the following initiatives that made this possible. We extend a congratulations to the interns on a job well done!

🌺 Akamai Workforce Initiative:
- Landen Amor Ildefonso mentored by Tim Williams & Rodell Agdinaoay
- Evan Zohar mentored by Andy Ferayorni
- Caleb DeSoto mentored by Sarah Jaeggli

⛰️ Boulder Solar Alliance REU:
- Mar-Isabelle Costacamps-Rivera mentored by Gianna Cauzzi and Kevin Reardon
- Joe Harkess mentored by Sushanta Tripathy
- Madeline Lundberg mentored by João da Silva Santos and Serena Criscuoli
- Peter Wu, mentored by Amr Hamada, Kiran Jain

Meet the students, explore their projects, and read the full story in our latest blog.

Undergraduate students complete solar science and engineering internships with the NSF National Solar Observatory.