HIGH-SPEED INFRARED PHOTOMETRY OF RAPIDLY OSCILLATING AP (ROAP) STARS - 10-AQUILAE

A controversy has recently been raised on the possibility of amplitude excesses in the oscillations of roAp stars when observed by means of rapid infrared photometry. Both marginally positive results for the J and K infrared bands (Weiss et al. 1990, 1991), and null results for the K band (Matthews et al. 1990) have been obtained. With the main aim of adding some work to this issue, high-speed photometric observations of the recently discovered roAp star 10 Aql were performed in the J(1.22-mu-m) filter. A total of 47.2 hours of data were obtained during seven consecutive nights in July 1990, using a standard infrared photometer attached to the Cassegrain focus of the 1.54 m Carlos Sanchez telescope at the Observatorio del Teide (Tenerife, Spain). As a first approach, the harmonic analysis of the data shows a noise level of about 0.8 mmag with the presence of marginal signal (DELTA-J approximately-1 mmag) in the visible (B band) photometric frequencies already reported in the literature (Heller & Cramer 1990). The possibility of interpreting these events as actual stellar signal will be discussed.