The relations between colors of the JHKL systems of SAAO (Glass et al. ), ESO (Engels et al. ; Wamsteker), CIT/CTIO (Elias et al.), MSO (Jones and Hylund; Hylund andMcGregor), AAO (Allen et al. ), and Arizona (Johnson et al. ) have been examined and linear relations derived to enable transformation between the (J-K), (J-H), (H-K), and (K-L) colors in the different systems. A homogenized system, essentially the Johnson-Glass system, is proposed and its absolute calibration derived based on the Bell model-atmosphere fluxes for a Lyr. The homogenized colors of the standard stars were used to derive intrinsic colors for stars with spectral types between B7 V and M6 V and G7 III and M5 III. The JHKL passbands of the MSO IR system, derived from measured filter passbands and estimated atmospheric transmission values, were used to compute synthetic colors from relative absolute fluxes of some stars (including the Sun). The reasonable agreement with the standardized JHKL colors indicates that these passbands can be adopted as representing the homogeneous system and used to compute broad-band IR colors from theoretical or observed fluxes. The passbands of other IR systems were similarly estimated from published data, and the synthetic colors were intercompared using blackbody and stellar fluxes. These passbands were then adjusted in wavelength to produce agreement with the observed relations between different systems, enabling the effective wavelengths of the different natural systems to be estimated. Better effective wavelength could be determined were spectrophotometry available for the very red stars with known broad-band colors.

No abstract

No abstract

No abstract