IRTF: What we hope to observe

During the 1983 eclipse something funny happened in the infrared spectrum.  In addition to the continuum from the F-star, additional absorption lines started to appear.  This doesn't seem that odd until one considers that some of the spectral lines, carbon monoxide (CO) in particular, did not appear until after mid-eclipse.  The high resolution spectra obtained during the ecipse also provided some other interesting details, but I'll let you read the paper to find out those tidbits of information.  (As an interesting sidenote, the integration times for these spectra were very long.  One spectra i particular took 670 minutes!  That's a little over 11 hours to get a single spectra!)

Now here comes the big question: where did the CO come from?  The F-star is too hot for CO to form so we can't find it there.  The leading edge of the disk doesn't cause CO emission so it isn't there either, right?  In our proposal we argued that the CO is present in the disk and is frozen down to grains of dust in the disk.  When the disk rotates past the F-star, it's intense radiation causes the CO to sublimate off of the grains and become a gaseious cloud like I've drawn below:

(yes, this really is a sketch in my notes.)

With such a hypthosis going into our observation, and data that already proves the CO is present only in the trailing edge of the disk, how are we going to get observing time?  The experiment has been done and proven to be true.  Fortunatly we are trying to prove a few things in addition to the apperance of CO and the sublimation off of grains.  Because this is an active research topic (which may result in a publication), I can't openly discuss it, but what I can talk about is how we go from having a need for data to applying for telescope time.  That's coming up in tomorrow's blog posting.