[vsnet-alert 11009] re Observe the hot disc of R CrB in the I band

[varposts at Safe-mail.net]

Not sure, but I think you need at least SEDs to assess disc temperature via models (Spectral Energy Distribution), which photometrically means that preferably as many folk as possible take B, V, Rc, Ic, J, H, K where feasible, hopefully to some density so that at least some are near contemporaneous, then models combining photosphere and disc and any halo can be churned out by them that know how.

CBAT seems to have made a note on R CrB's fade too, so there'll likely be some R and/or r' and some K of some version from professional scope ToO, these seem to be the optical and NIR passbands most quoted on GCNs and ATELs for instance.  Both Spitzer and Akari are in warm stage now, but still available for some limited passband use, so hopefully ToO for some MIR bands will be available too, not sure if FIR is possible in warm mode, and I forget what bands Akari is going to continue with.  The longer the wavelength the better to some extent, so possibly the millimetre and submillimetre 'scopes around nowadays may play too.

Of course this kind of also needs there to be optical, NIR, MIR and FIR available for nonfade states, and dunno if IRAC or MIPS can cope with full brightness R CrB.

Certainly some Ic would be nice, and B-V in tandem with V-Ic could be informative.

Cheers

John