Solar alert

Issued on 2023 Jul 18 0905 UTC

A halo coronal mass ejection (CME) was observed in LASCO/C2 coronagraph data from 23:50 UTC on July 17, as an initial estimate the projected speed is over 1000 km/s. The CME is associated with an M5.7 flare originating from NOAA AR 3363 near the south west limb, which also caused a proton event. The greater than 10 MeV proton flux crossed the 10 pfu threshold on 18 July at 01:15 UTC and reached a maximum value of 620 at 06:15 UTC. The proton flux is expected to remain above the threshold over the next hours. Analysis of the CME is ongoing but, due to the location of the CME origin, a glancing blow at Earth may be possible.

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