Solar activity
What the Sun itself is doing: how bright it is in X-rays, which regions carry the twisted magnetic fields that produce flares, and what has actually erupted.
X-ray flux and the current flare
LiveB2.1
Minor; no noticeable effects.
- Reading taken
- 2026-09-17 07:08 UTC
- Satellite
- GOES-18
- Event began
- 2026-09-16 11:46 UTC
- Peak
- 2026-09-16 11:53 UTC · B3.4
- Event ended
- 2026-09-16 12:03 UTC
10.7 cm radio flux
F10.7
Live100sfu
Moderate activity
A typical mid-cycle value. Active regions are present and capable of producing flares.
- Measured
- 2026-09-16 20:00 UTC
- Type
- Published index
- Provider
- NOAA Space Weather Prediction Center
A disc-integrated index in solar flux units (10⁻²² W m⁻² Hz⁻¹), measured daily.
Why this index
The 10.7 cm radio flux has been measured daily since 1947, which makes it the longest continuous instrumental record of solar activity. It tracks the magnetic complexity of the corona closely enough to serve as a proxy for it, and unlike sunspot counting it does not depend on an observer's judgement or on clear skies.
Active regions on the visible disc
Live4 numbered active regions in the report for 2026-09-17, with 3 sunspots counted across 2 of them — NOAA published no spot count for the 2 remaining.
| Region | Location | Area | Spots | Class | M / X flare chance |
|---|---|---|---|---|---|
| 4527 | N03W0* | 130 | 2 | Hax / A | 0% / 0% |
| 4528 | S11W83 | 120 | 1 | Hsx / A | 1% / 1% |
| 4529 | N14W70 | — | — | — | 0% / 0% |
| 4531 | S08W37 | — | — | — | 0% / 0% |
Catalogued solar flares
Live- C3.4region 14524N15W05began 2026-09-09 08:48 UTC · peak 09:08 · DONKI record
- C2.4region 14521N10W35began 2026-09-08 12:19 UTC · peak 12:24 · DONKI record
- C5.0region 14524N12E32began 2026-09-06 10:31 UTC · peak 10:42 · DONKI record
- C8.5region 14524N12E42began 2026-09-05 17:32 UTC · peak 17:46 · DONKI record
- M1.0region 14520S12W68began 2026-09-05 15:04 UTC · peak 15:18 · DONKI record
- C6.4region 14524N12E45began 2026-09-05 10:24 UTC · peak 10:45 · DONKI record
- C6.7region 14524N12E55began 2026-09-04 19:02 UTC · peak 19:30 · DONKI record
- M1.2region 14524N14E71began 2026-09-04 07:45 UTC · peak 07:53 · DONKI record
- C2.2region 14523N11E44began 2026-09-03 09:35 UTC · peak 09:42 · DONKI record
- M3.0region 14524N12E90began 2026-09-02 18:57 UTC · peak 19:20 · DONKI record
Region numbers here are DONKI's full five-digit NOAA numbers. NOAA's daily region report, above, publishes the last four digits of the same number — so DONKI's region 14518 and the report's region 4518 are one region. Neither provider's value is rewritten.
DONKI is NASA CCMC's analyst-curated research catalogue, and CCMC states that its real-time contents “should be considered only as prototyping quality and in research context”. Curation lags events by hours, so an empty list here means nothing has been catalogued yet — not that nothing happened. For operational status, read the SWPC alerts above.
Catalogued coronal mass ejections
Live- 395 km/shalf-angle 16°first seen 2026-09-15 08:36 UTC · DONKI record
Very faint CME/outflow with a fuzzy, unclear front seen to the NE in early images of SOHO LASCO C2 only. It is not seen in SOHO LASCO C3, STEREO A COR2 and GOES CCOR-1, likely because of its faintness. No source for this feature has been found in EUV imagery.
- 461 km/shalf-angle 19°first seen 2026-09-14 17:24 UTC · DONKI record
CME observed to the NW in SOHO LASCO C2/C3 and GOES CCOR-1, likely not observed in STEREO A COR2 either due to faintness or a data gap starting at 2026-09-14T18:53Z before it becomes visible. The source is far-sided over the NW limb, observed in SDO AIA 171/193 starting around 2026-09-17T15:48Z as slow, wide field line movement. More directly observed in STEREO A EUVI 195/304 starting as early as 2026-09-14T14:55Z, as brightening and dimming centered around an estimated N30W115 in the NW disk near former Active Regions 14523 and 14521.
- 744 km/shalf-angle 24°S11W38first seen 2026-09-14 11:08 UTC · DONKI record
CME first seen to the E in STEREO A COR2 starting at 2026-09-14T11:08Z. It is also seen to the W in GOES CCOR-1. This CME is covered by a data gap in SOHO LASCO C2/C3 in real time. The source of this CME is an eruption centered around AR 14528 (S11W38) best seen in GOES SUVI 284 beginning around 2026-09-14T10:00Z. Field line movement can be seen accompanied by brightening and ejecta. Post-eruptive arcades can also be seen in SDO AIA 193. There seems to be a northwestward deflection from the location of the source. There are two large coronal holes (a northern and a southern one) nearby, possib…[truncated]
- 645 km/shalf-angle 22°S10W10first seen 2026-09-13 21:12 UTC · DONKI record
Faint CME first seen to the West by SOHO LASCO C2 beginning at 2026-09-13T21:12Z, as well as by SOHO LASCO C3 and GOES CCOR-1 in later frames. This event is not seen in STEREO A COR2 due to a data gap which began at 2026-09-13T19:23Z. The source of this CME is likely outflow following an earlier filament eruption beginning at 2026-09-13T18:48Z centered at approx. S10W10 as seen in SDO AIA 193 and 304. This CME is likely deflected to the NW due to proximity to a large coronal hole.
- 1305 km/shalf-angle 23°S10W10first seen 2026-09-13 19:48 UTC · DONKI record
CME first seen to the West by SOHO LASCO C2 beginning at 2026-09-13T19:48Z, as well as by SOHO LASCO C3 and GOES CCOR-1. This CME is not seen in STEREO A COR2 due to a data gap beginning at 2026-09-13T19:23Z. The source of this event is a center disk filament eruption beginning at approx. 2026-09-13T18:48Z best seen in SDO AIA and STEREO A COR2 304, centered at approx. S10W10. This filament appears to be deflected towards the NW, which is supported by dimming seen moving towards the NW, expanding to approx. N10W30 as seen in SDO AIA 193. This eruption is close to a large coronal hole which may…[truncated]
- 295 km/shalf-angle 22°first seen 2026-09-13 10:23 UTC · DONKI record
CME first seen to the W in STEREO A COR2 starting at 2026-09-13T10:23Z and fades before leaving the FOV of STEREO A COR2. This feature is not see in SOHO LASCO C2/C3 or in GOES CCOR-1. The source is likely related to field line movement seen beyond the WNW limb in STA EUVI 195 beginning after 2026-09-13T08:00Z.
- 319 km/shalf-angle 10°first seen 2026-09-13 07:48 UTC · DONKI record
Very narrow CME first seen to the SW in SOHO LASCO C2 starting around 2026-09-13T07:48Z. It is first seen part way into the FOV of SOHO LASCO C2 and is also seen in SOHO LASCO C3 and GOES CCOR-1 but not in STEREO A COR2. The source may be related to minor field line movement beyond the SW limb best seen in SDO AIA 171 beginning around 2026-09-13T06:00Z.
- 403 km/shalf-angle 19°first seen 2026-09-13 01:24 UTC · DONKI record
CME first seen to the W in SOHO LASCO C2 starting at 2026-09-13T01:24Z. It is also seen to the W in SOHO LASCO C3. This CME is mostly obscured by Earthshine in GOES CCOR-1 and is not seen in STEREO A COR2. There is no definitive source candidate, but the source may be related to some minor activity in a filament structure over the W limb best seen in GOES SUVI 304 beginning around 2026-09-13T22:30Z.
Most coronal mass ejections are not directed at Earth. A speed here describes the ejection, not an impact: whether one reaches Earth, and when, is a separate modelled question that this catalogue does not answer.
DONKI is NASA CCMC's analyst-curated research catalogue, and CCMC states that its real-time contents “should be considered only as prototyping quality and in research context”. Curation lags events by hours, so an empty list here means nothing has been catalogued yet — not that nothing happened. For operational status, read the SWPC alerts above.
Two kinds of flare record
The X-ray panel above is an instrument reading: the flux GOES is measuring in the 1–8 Ångström band at this moment, expressed as a flare class. It is current to the minute and it is not curated. A flare in progress has no end time and its class can still rise.
The catalogued flares are a research record: events reviewed by NASA CCMC analysts, with begin, peak and end times and an associated active region. Curation lags the event by hours, so the most recent hours are routinely incomplete. An empty catalogue is not evidence of a quiet Sun.
AsteriaStar shows both and never merges them. They are produced by different processes with different latencies and different purposes, and a single combined list would inherit the weaknesses of each.
Provenance
Every value on these pages is fetched from NOAA SWPC or NASA CCMC and carries the provider's own timestamp. Nothing is simulated, interpolated or filled in: when a provider cannot be reached, the panel says so and shows no number. There is no overall “space weather score” here — the agencies publish scales, and a single figure invented on top of them would be an opinion wearing NOAA's authority.
GOES X-ray flare state
Live- Status
- Live
- Kind
- Observation
- Provider
- NOAA Space Weather Prediction Center
- Organisation
- NOAA / National Weather Service
- Fetched
- 2026-09-17 07:12 UTC
- Generated by provider
- 2026-09-17 07:08 UTC
- Provider cadence
- 1 min
- Cached for
- 1 min
- Treated as stale after
- 3 h
- Licence
- Public domain (US Government work). No licence fee and no redistribution restriction.
Source file: https://services.swpc.noaa.gov/json/goes/primary/xray-flares-latest.json
GOES X-ray flare (latest) from NOAA Space Weather Prediction Center, fetched from https://services.swpc.noaa.gov/json/goes/primary/xray-flares-latest.json. GOES X-ray fluxes are published each minute; the cache matches the cadence.
The current or most recent flare seen by the primary GOES satellite in the 1–8 Ångström band. A flare in progress has no end time yet, and its class can still rise.
Active regions
Live- Status
- Live
- Kind
- Observation
- Provider
- NOAA Space Weather Prediction Center
- Organisation
- NOAA / National Weather Service
- Fetched
- 2026-09-17 07:12 UTC
- Generated by provider
- 2026-09-17 00:00 UTC
- Provider cadence
- 1 d
- Cached for
- 1 h
- Treated as stale after
- 4 d
- Licence
- Public domain (US Government work). No licence fee and no redistribution restriction.
Source file: https://services.swpc.noaa.gov/json/solar_regions.json
Solar active regions (daily report) from NOAA Space Weather Prediction Center, fetched from https://services.swpc.noaa.gov/json/solar_regions.json. A once-daily synoptic report. An hour's cache cannot make a daily product stale.
Numbered active regions from the daily solar region summary, with sunspot area, magnetic and spot classification. The spot totals here are counts within numbered regions and are NOT the International Sunspot Number, which is defined differently and published by SILSO.
10.7 cm radio flux
Live- Status
- Live
- Kind
- Published index
- Provider
- NOAA Space Weather Prediction Center
- Organisation
- NOAA / National Weather Service
- Fetched
- 2026-09-17 07:12 UTC
- Generated by provider
- 2026-09-16 20:00 UTC
- Provider cadence
- 1 d
- Cached for
- 1 h
- Treated as stale after
- 4 d
- Licence
- Public domain (US Government work). No licence fee and no redistribution restriction.
Source file: https://services.swpc.noaa.gov/products/summary/10cm-flux.json
10.7 cm solar radio flux from NOAA Space Weather Prediction Center, fetched from https://services.swpc.noaa.gov/products/summary/10cm-flux.json. F10.7 is a daily index; an hour's cache is far finer than its resolution.
The daily 10.7 cm radio flux in solar flux units, the standard long-run proxy for solar activity. It is a disc-integrated index, not a measure of any one region.
DONKI flare catalogue
Live- Status
- Live
- Kind
- Observation
- Provider
- NASA DONKI
- Organisation
- NASA Goddard Space Flight Center / Community Coordinated Modeling Center
- Fetched
- 2026-09-17 07:12 UTC
- Provider cadence
- 1 h
- Cached for
- 15 min
- Treated as stale after
- 6 h
- Licence
- Public domain (US Government work), subject to NASA's media usage guidelines.
Source file: https://kauai.ccmc.gsfc.nasa.gov/DONKI/WS/get/FLR?startDate=2026-08-18&endDate=2026-09-17
Solar flare catalogue from NASA DONKI, fetched from https://kauai.ccmc.gsfc.nasa.gov/DONKI/WS/get/FLR?startDate=2026-08-18&endDate=2026-09-17. A curated catalogue updated by analysts through the day, not a live stream; fifteen minutes bounds the delay on a newly-catalogued event without polling a research service every request.
Analyst-curated flare records for the last 30 days, with begin, peak and end times and the associated active region. Curation lags the event, so the most recent hours may be incomplete — an absent flare is not evidence of a quiet Sun.
Sources & references
The primary and reference sources this topic draws on.
- NOAA SWPCNOAA Space Weather Prediction Center
Space-weather forecasts and alerts: aurora (OVATION), the Kp index, and the G1–G5 geomagnetic storm scale.
- NASA DONKINASA Community Coordinated Modeling Center
The Space Weather Database Of Notifications, Knowledge, Information: solar flares, CMEs, and geomagnetic storms.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.