Improved SAAO–2MASS photometry transformations

Abstract

Near-infrared photometry of 599 stars is used to calculate transformations from the South African Astronomical Observatory (SAAO) JHK system to the Two-Micron All-Sky Survey (2MASS) JHK S system.Both several-term formal regression relations and simplified transformations are presented.Inverse transformations (i.e.2MASS to SAAO) are also given.The presence of non-linearities in some colour terms is highlighted.