Excess continuum radiation from an unresolved binary companion in the CGS4 slit may be mistaken for veiling local to the T Tauri star. Lists of known binary T Tauri stars in Taurus were therefore consulted [Ghez et al. 1991, Ghez et al. 1993, Leinert et al. 1993, Richichi et al. 1994, Mathieu 1994, Simon et al. 1995, Ghez et al. 1997] to check if any of our sample are known to be binaries that would be unresolved to our slit.
T Tau is a binary system (separation 
) with a cool
infrared companion star [Ghez et al. 1991] which might be
contaminating the near infrared spectrum and therefore making it look
like that of a later spectral type object.
HP Tau is a binary system with a separation of 
which might
make the near infrared spectrum of HP Tau look like that of a star with a
later spectral type.
V773 Tau is a multiple system with an unresolved component that contributes considerably to the total spectral energy distribution [Ghez et al. 1997] which is likely to be of K5V spectral type.
DF Tau, DI Tau, FS Tau, GG Tau, GH Tau, LkCa7, UY Aur, V807 Tau, VY Tau
and ZZ Tau are all binary stars with separation less than 
[Mathieu 1994]. Despite that, the near infrared spectrum corresponds to
the spectral types expected from the optical.