What's up with the SOHO?

On the SOHO home page, the first 4 EIT cameras are showing as 'CCD BAKEOUT' - does this happen often and what causes it?
Does it signify an increase in solar radiation or something?

sohowww.nascom.nasa.gov...

The CCD is warmed for some time to evaporate dirt on it: What's a CCD bakeout, anyway? It can't be used to take picture during that time.

I hope this answers your question:

What's a bakeout?
In order to (i) keep read noise down (suppress the "snow") and (ii) prevent cosmic ray hits from permanently raising the read noise level by damaging the detector, the EIT CCD is usually operated at a temperature of about -67 C. This temperature is achieved by passive cooling: the CCD chip is thermally contacted to a titanium "cold finger" (at far left in the image above) that is attached to a radiator plate that is pointed at a piece of sky perpendicular to the earth-Sun line.

umbra.nascom.nasa.gov...

EDIT: Ah, Amantine, you got to it before I did. :-D

[Edited on 6-17-2004 by EmbryonicEssence]

Thanks for the info!! That explains it!