Linear, and sometimes two-line, transformations are often acceptable for VRI photometry but they are not rigorous.
We present the saturation and colour corrections required to relate the natural system of the MkII JHKL photometer.
The St Andrews Scanner has been used to determine the atmospheric extinction at SAAO Sutherland.
Approximate relations between colour equations and mean reciprocal wavelengths are given for bands in the red and near infrared.
A spectrum of the star van Biesbroeck 8 shows that it is an M dwarf of very late type.
Isolated extragalactic H II regions are dwarf galaxies undergoing a burst of star formation.