Global helioseismology products by Dr. Sylvain Korzennik

Dr. Sylvain Korzennik (Center for Astrophysics Harvard & Smithsonian) has completed the fitting of more HMI and GONG data, using time series of various lengths, up to for GONG: 2025.04.04 (GONG month #304), and for HMI: 2025.04.23 (MDI mission day #11800). He also fitted all the MDI data, or 76 x 72 days (14.98 yr) and the corresponding GONG time interval (1996.05.01 to 2011.04.25). 
 

The tables are available at his website and have been ingested into the JSOC.
 

He has started fitting all the GONG data as one 30 year long time series (152 x 72 days). Note that this time series starts on GONG month 1 or 1995.05.07 (vs MDI's 15 years that starts on MDI mission day no 1216, or 1996.05.01). 

Next, he plans fitting a 15 year long GONG time-series offset by 7.5 year from 1996.05.01 (i.e., 2003.10.28 to 2018.10.21). 

Large filament eruption on 31 July 2025

 

Large chromospheric filament erupted on the North-East limb on 31 July 2025, and later, other prominence had erupted from the same limb. Video covers 00:00:42 UT - 09:12:42 UT as observed by GONG at Learmonth, Australia.  

GONG/TD fiber-optic connection

Monday morning, 28 July, about 8am local time, the fiber-optic cable to GONG at Teide was damaged.  An external company was called in. The repairs started later same day, and were competed next morning. GONG/TD is back on line, but the inspection indicated that the fiber-optic connectors are very old and not in a very good condition. The company is developing a plan for replacing these connectors with new standard ones. The date of this additional work is not yet determined. GONG/TD continued taking observations during this period, and no data were lost due to the incident.

GONG/TD LCVR temperature control issue

After the last Preventative Maintenance at the GONG Teide (TD) site (Canary Islands, Spain) that ended on June 1st, GONG QA monitor showed excessive scatter in airstats plots. The potential issue was traced down to the temperature control of the LCVR (Liquid Crystal Variable Retarder). Preliminary science tests didn't show any problem with the data. As a temporary solution, the LCVR temperature control was turned off on June 24th. The TD airstats came back to normal. A sharp boundary between the data points distribution before and after the LCVR temperature control was disabled is seen on the Figure. We are working to confirm that the problem didn't affect the data.

GONG refurbishment project update

NISP group has successfully completed vetting one of the GONG EVT cameras that will upgrade one of the engineering sites in Boulder, CO. Engineering group has already mounted the next new EVT camera, one of the two that still needs to be vetted, and we are going to start vetting the data from this camera as soon as we have enough good sunny days.

 

 

Fun prominence eruption

 

Watch how a remote erupting feature "flies" through the prominence and destabilizes it.

GONG/BB connectivity issues (updated on 7/22/2025)

On 19 July, GONG/Big Bear experienced issues with connecting to the network. Rebooting bbgong workstation did not fix the issue. The team reached out to the local support team asking them to investigate.

As an update (7/22/2025): The issue was traced to a failure of BBSO Netgear switch's Female Transceiver Port for Fiber connection. The failed part was replaced, and the connection to GONG/BB has been restored. 

GONG Duty Cycle

On November 28, 2022, the volcanic eruption shut down the NSF's GONG station at Mauna Loa, Hawai'i. Since then, GONG operated as 5-station network. It was designed as 6-station network because of helioseismology requirements of high duty cycle (fraction of 24-hour day with solar observations). The plot shows the duty cycle through April 2025. GONG still meets the helioseismology requirements, but one can clearly see a drop in the duty cycle at the end of 2022 from about 95% to 85-90%. The plan is to restart GONG station at Mauna Loa by the end of this year, after the road access and the electric power are restored.

NISP data server

Work has started on replacing current Isilon data server by new Ceph cluster. Hardware for a development (sandbox) server has arrived (see photo), and it will be installed later this year. Factoring in redundancy and object storage overhead, the usable capacity in the Ceph production cluster will be around 1.5PB. In comparison, the usable storage capacity of the existing Isilon cluster is about 1.0PB of which about 913TB is currently used.

GONG data processing update

 

Processing of the network-merged daily velocity and magnetogram images, p-mode-coefficient time series, and ring-diagram analysis products for GONG month 304, and the p-mode frequency data products for central GONG month 303 is completed and the data products are now available. 

Mauna Loa Access Road

The Central Federal Lands Highway Division of the Federal Highway Administration has updated its "Request for Qualifications (RFQ)" on sam.gov with new due date 9 July 2025. That means that the schedule for Mauna Loa Access road is delayed by about a month with road completion estimated in Nov 2025. 

 

Large prominence eruption on 5 July 2025

See a large prominence at the North-West limb of the Sun rising and erupting as observed by GONG stations at Learmonth, Australia and Teide, Canary Islands on 5 July 2025, between 03:00:42 UT and 11:06:11 UT.

NISP group continues working on the GONG refurbishment project.

NISP Data Center, scientists, and engineers are currently vetting another new EVT (Emergent Vision Technologies) GONG camera at one of the NISP engineering sites in Boulder, Colorado. Five of the EVT cameras have already replaced old SMD (Silicon Mountain Design company) cameras at five sites of the GONG network. We have two more EVT cameras to vet. The two cameras and the one being currently tested, will upgrade the engineering sites.