GONG Big Bear station

Broadband image from GONG/BB

GONG Big Bear station is exhibiting an unusually large number of camera resets. Each reset interrupts normal observing sequence, and impact the continuity of observations. This happen after recent unplanned power outage.  Engineering team is developing a mitigation approach to resolve the issue.

Flares, filament eruptions, but no CME?

Major (M- and X-class) flares and filament eruptions are usually accompany CMEs, but not always. On 31 August 2025 at about 14:00 UT, M1.3-class flare was recorded in NOAA active regions 14197. This is the region that had about hundred sunspots early this week. The flare activated large quiescent filament south of this region with a partial filament eruption at about 16:15 UT  (upper panel). Then, at about 18:00 UT a small two-ribbon flare and filament eruption were observed in NOAA region 14202 to the East of region 14197 (second panel from the top). See GONG video of these events at the bottom panel.  Despite this activity, there was no obvious sign of CMEs in LASCO coronagraph. There is gap in observations in LASCO C2 between 17:24 UT and 18:36 UT, and coronal streamers appear to be pushed apart during this gap. So, maybe it was a CME but LASCO missed it? Or maybe these were the  failed filament eruptions? 

Sunspot group with hundred sunspots

 Sunspots are organized in groups (or active regions). On average, active regions have only about 6-8 sunspots, but sometimes there are groups with much more sunspots. Sunspot drawing from the National Solar Observatory at Sacramento Peak Observatory taken 2 Sep. 1959 shows two groups with 81 and 93 sunspots. Early this week, an active region with about hundred sunspots was observed by GONG (see colored image showing a zoomed-in portion of solar broaband image of the Sun taken by GONG/Big Bear station in California. GONG telescopes have relatively small aperture, and thus, some small sunspots may not be visible. Observations with larger aperture telescopes suggest that there were close to 100 sunspots in this active region. 

C-class flare as observed by GONG/LE

On 26 August 2025, GONG at Learmonth (Australia) caught C6.2 flare in active region 14199 near solar East limb. Only a small eruption associated with this flare could be seeing in LASCO C2 coronagraph at about 1:26 UT. Video of this flare created by Niles Oien is available in GONG gallery.

Adverse Weather Conditions Interrupt GONG’s Continuous Observations

 Recent adverse weather conditions at multiple GONG sites have significantly disrupted observations, resulting in a markedly low duty cycle. Consequently, the seismic far side maps exhibit elevated noise levels.

GONG refurbishment project update

NISP Data Center, scientists, and engineers started vetting next EVT (Emergent Vision Technologies) camera installed at one of the GONG engineering sites in Boulder. This camera is one of the two that still need to be tested. Both cameras will upgrade the engineering sites. Five of the EVT cameras have already replaced old SMD (Silicon Mountain Design company) cameras at five sites of the GONG network.

Huge prominence eruption

 A huge prominence erupts from South-East limb in early hours of August 20, 2025. Day earlier, this region produced a major M-class flare. Such large prominence eruptions could be associated with a major geomagnetic storms impacting Earth's global infrastructure and satellites. This time, however, no geomagnetic storm is expected as the coronal mass ejection associated with this prominence eruption would miss the Earth. These observations are taken by GONG station at Learmonth, Australia. Erupting prominences (filaments on the disk) are closely associated with the coronal mass ejections - the major source of space weather.