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(From John Greaves) Date: Mon, 9 Jun 2003 18:50:15 +0000 Subject: Re: V Cyg On 9 Jun 2003, Ondrej Pejcha wrote: > However, the flare in V Cyg is real, as far as I can say. I > have the images at home and have performed various checks. > There is no hot pixel and the profile is Gaussian with the > same FWHM as other stars in the image have. The star is > _significantly_ brighter than on the image taken 4 days > before. I can send the images to interested folks. V Cyg... ...carbon star That stuffs just about all the evidence and _all_ of the theories in the papers on flaring. Of course, there's nothing to stop several classes of objects flaring, from either the same or different mechanisms, but the theories place their bets on oxygen rich M type star capable mechanisms only. MSX5C data does show this to be variable in a passband normally associated with silicate emission though, whilst not variable in the other bands as would occur for continuum variation (and I can't remember where the "graphite bump" is, 19 microns? anyone? an ADS search on graphite and bump is not too helpful, too many irrelevant hits!). In MSX5C data it is also apparently stable and twice as "bright" (properly: twice the flux) in the 12 micron band, and about similarly bright in the 15 micron band. It's also brightest at 12 microns in IRAS, getting fainter towards 100 microns. Cheers John (NB note that I've already discounted the Maffei et al paper as being not pertinent to this particular matter as it calls a 'rapid variation' some thing that is on the 2 to 30 days timescale, which is not what we're on about here).
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