A Powerful Sequence of Flares Start September 2017
- Produced by:
- Scott Wiessinger
- View full credits
Short video showing the sequence of M and X flares starting on September 4, 2017 and culminating with an X9.3 flare — the largest of the solar cycle.
Music: "Networked" from Killer Tracks
Watch this video on the NASA Goddard YouTube channel.
Complete transcript available.
One minute video showing the two X flares on September 6, 2017. The second was an X9.3 flare — the largest of the solar cycle.
Music: "Networked" from Killer Tracks
Complete transcript available.
Active region 2673 emitted a series of flares in early September, 2017, including:
--an M5.5 at 4:33 p.m. EDT on Sept. 4, 2017
--an X2.2 at 5:10 a.m. EDT on Sept. 6, 2017
--an X9.3 at 8:02 a.m. EDT on Sept. 6, 2017
--an M7.3 at 6:15 a.m. EDT on Sept. 7, 2017
--an X1.3 at 10:36 a.m. EDT on Sept. 7, 2017
--an M8.1 at 3:49 a.m. EDT on Sept. 8, 2017
--an X8.2 at 12:47 p.m. EDT on Sept. 10, 2017
NASA’s Solar Dynamics Observatory, which watches the sun constantly, captured images of the events. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel.
To see how this event may affect Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.
X-class denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc.
The X9.3 flare was the largest flare so far in the current solar cycle, the approximately 11-year-cycle during which the sun’s activity waxes and wanes. The current solar cycle began in December 2008, and is now decreasing in intensity and heading toward solar minimum. This is a phase when such eruptions on the sun are increasingly rare, but history has shown that they can nonetheless be intense.
September 10, X8.2

Different views of the X9.3 flare from Sept. 6, 2017. On the left, it flashes in a blend of 131 and 171 angstrom light. On the right it shows light in both visible and 304 angstrom extreme ultraviolet wavelengths, revealing both sunspots visible on the Sun's surface and the flare in the solar atmosphere.>Credit: NASA/GSFC/SDO
For More Information
See https://www.nasa.gov/feature/goddard/2017/two-significant-solar-flares-imaged-by-nasas-sdo
Credits
Please give credit for this item to:
NASA's Goddard Space Flight Center. However individual items should be credited as indicated above.
Visualizer
- Tom Bridgman (GST)
Science writer
- Karen Fox (ADNET)
Producer
- Scott Wiessinger (KBRwyle) [Lead]
Technical support
- Aaron E. Lepsch (ADNET)