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Impressive eruption

An impressive eruption took place over the Sun's southwest limb on 24 June. The source was NOAA 3712, but there were interactions with the other nearby big group NOAA 3713 as well. In soft x-ray (GOES) and in UV (PROBA2/LYRA), the eruption seems to have started late on 23 June, peaking around 05 UTC on 24 June around the M1 level, and lasting for the better part of that day (see the combined GOES and PROBA2 chart underneath). On itself, this flare was not registered by GOES as it evolved too slowly. The spikes on the overall evolution result from other, more short-lived eruptions in NOAA 3712 and 3713, NOAA 3716 (another big region close to the northwest limb) and the returning old sunspot group NOAA 3664 (near the southeast limb ; 3rd appearance). As the sunspot complex NOAA 3712/3713 rotated further onto the farside of the Sun, one can also see the soft x-ray and UV background flux quickly dropping early on 25 June.

The imagery below shows the eruption in extreme ultraviolet (EUV), with SDO/AIA 171 showing temperatures around 700.000 degrees (yellowish green), and AIA 131 showing the much hotter parts of the eruption at multi-million degrees (orange-reddish colours). The image underneath shows the area around the time of flare maximum, when also the hottest portion (reddish) was the most extensive. The hottest parts of the flare suggest the presence of supra-arcade downflows (SAD). These features have been discussed in detail in this STCE newsitem, providing also many more examples of SADs. The post-eruption coronal loops that can be seen growing in height, eventually towered at least 182.000 km over the solar surface, that is half the Earth-Moon distance. They were still visible early on 25 June.

A partial halo coronal mass ejection (CME) was associated with this eruption, directed to the southwest. The SIDC forecaster has analyzed this CME, and came to the conclusion that it has no earth-directed component in view of the source location. The imagery underneath combines EUV imagery by SUVI 304 (GOES) with white light coronagraphic images by SOHO/LASCO C2.