Re: New Draft: NSV 10892

[aah@nofs.navy.mil]

Going through old email.  Michael K wrote:
>This is probably a dumb question, but are these systems 
>generally Main Sequence or Supergiants? In Astrophysical 
>Quantities, using the table for calilbration of MK spectral 
>types, Arne's photometry groups together more tightly on the 
>supergiants table than on the main sequence table.
  First, Astrophysical Quantities still uses Johnson R and I,
not Cousins Rc and Ic.  Much of that text was not updated, so
you have to be careful when perusing the latest edition.
  Second, with 4 broadband colors, you can say something
about the spectral type but rarely something about the
luminosity class; just not enough information.  So don't
worry about 'groupings'.
Arne