Multicolor observations of stars in the vicinity of the Orion Nebula

Photometry in nine colors from 0.3 to 3.4 M of all stars brighter than V = 12 mag within half a degree square centered on 61 Orionis is presented. Additionally about one-half of this area is searched for stars which, although visually fainter than twelfth magnitude, have 2.2- magnitudes brighter than about 8 mag. Several stars with infrared excesses and a few highly reddened stars are found. These two types of stars can be separated in an infrared two-color diagram. No star earlier than B9 has a significant infrared excess at 2 . There is a good correlation of 2- excess with optical variability. For those stars with spectral types, the visual absorption can be deduced. This varies greatly from star to star and does not correlate with position or luminosity and only weakly with 2- excess. There is, however, a probable correlation of visual absorption with optical variability. For nearly all stars more energy is absorbed in the visual region than is reemitted in the infrared at wavelengths up to 3.4 . Subject headings: infrared sources - interstellar reddening - Orion Nebula