The Flare that Time Forgot
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Nugget | |
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Number: | |
1st Author: | Paulo Simões |
2nd Author: | Hugh Hudson |
Published: | October 14, 2013 |
Next Nugget: | TBD |
Previous Nugget: | The Post-Burst Increase |
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Introduction
RHESSI, over its lifetime in space thus far, has detected many, many flares. Often a single event inspires a single paper, and then a flood of literature even if it's not very typical The Masuda flare [1] would be a case in point, and we've had Nuggets on this topic before: "An alternative view...", "Acceleration without heating", "Acceleration-region densities", etc. In spite of this it is generally held that this particular event was of quite a rare type. Thus we were amazed when a retrospective view of the RHESSI flares disclosed that the very first M-class flare observed by RHESSI looks very much like a Masuda flare! Somehow nobody picked up on this one, in spite of its newsworthiness. See Browser for a concise overview.
How do we know nobody studied this one?
The RHESSI book [2] has an extensive index, which makes use of the now-standard IAU target designation scheme. A flare, in this scheme, has an identifier such as SOL2002-02-20T10:04 (with the option of an extension for location). This makes it easy to search any database, and (for example) a Google search just brought up an entire page of SOL2002-07-23 - but none of the "Flare that Time Forgot". The RHESSI index has one entry, for a study of the albedo patch, but nothing concerning the interesting coronal developments. By contrast everybody's favorite SOL2002-07-23 has no fewer than 79 entries, and featured in Bob Lin's final chapter of the book specifically because of its Masuda-like properties. The "flare that time forgot" of course had not made the top-10 list of RHESSI flares.
The flare
A couple of images show some of the attributes of this flare. Figure 1 shows soft, medium, and hard X-ray images via two imaging algorithms. They show the familiar cusp to be present at 25-50 keV, and above it a significant 50-keV source. In other words, it is possibly a much-sought-for Masuda event, and there it was on RHESSI's plate 11 years ago.
RHESSI Nugget Date | 14 October 2013 + |
RHESSI Nugget First Author | Paulo Simões + |
RHESSI Nugget Second Author | Hugh Hudson + |