Two-micron objects in the northern Monoceros region.

A two-micron survey uncovered 55 objects in a 4 X 2040 area of the northern Monoceros region with a minimum detectable magnitude K--5.5. They were identified on a near-infrared photographic plate, and broad-band photometry of the wavelength range 0.35-3.5 m and spectroscopic observations with an objective prism revealed the photometric properties of these objects. It is found that many of these objects are reddened late-type giants. In particular, object No. 17 in our list is a carbon star V493 Mon with an infrared excess newly found in this study. The interstellar extinction curve was found normal. The amount of interstellar extinction and the space density of late-type giants were estimated. Key words: Infrared objects; Interstellar extinction; Late-type giants; NGC 2264.