25. Stellar Photometry

Abstract

During the past three years there has been increased activity in many fields where photometric methods are employed; more telescopes have been commissioned or adapted for photometric measurements and new magnitude systems have been proposed and tried, but much of the observing is now of a routine nature. Most of this continues to be done in the wide-band UBV system, but more measurements are now being made in the red and infra-red.More interest is being shown in narrower band-widths that emphasize particular features of a stellar spectrum, because these offer better prospects of separating the effects of temperature, luminosity, interstellar reddening, composition and duplicity. Attention has been given to finding the most useful bands and practical ways of measuring them, both photoelectrically and photographically.