Published online by Cambridge University Press: 12 April 2016
The accuracy with which infrared photometry can be carried out is currently limited by poor definition of the instrumental system and by the accuracy of the available standard stars. We present new colour transformations between the CIT J, H, K photometric system and systems currently in use at Cerro Tololo, Mauna Kea and Kitt Peak. The precision of the J, H, K data for some of the stars observed by Elias et al. is improved and the system extended to fainter stars suitable for use with larger telescopes and/or infrared arrays. Evidence of infrared variability has been detected for one M dwarf star in our programme.