THE RR LYRAE POPULATION OF THE LMC .1. THE IMMEDIATE ENVIRONMENT OF NGC-2210

We present results of a CCD-based survey for RR Lyraes in various regi ons of the Large Magellanic Cloud (LMC). This first study is part of a long-term programme which aims to use RR Lyraes to map the distributi on and kinematics of the oldest stellar population in the LMC. Our dat a cover a 15 x 15 arcmin2 field in the vicinity of the LMC globular NG C 2210. We have identified 44 moderate-amplitude variable stars, of wh ich 31 were known from the previous surveys summarized by Hazen & Neme c. Our field of view includes a further eight stars from the latter su rvey, only one of which - a low-amplitude variable near the cluster ce ntre - is confirmed as variable by our observations. At least 27 of th e variables are RR Lyraes, the majority of which clearly are associate d with NGC 2210. The mean magnitude of the RR Lyraes most distant from the cluster centre, which we suggest as likely LMC members, is 0.1 ma g fainter than that of the cluster variables. If the field stars have the same mean abundance as NGC 2210, this implies that the cluster is approximately 2 kpc in front of the LMC, and, allowing for the tilt of the LMC as a whole, we derive a distance modulus of 18.3 to 18.5 to t he centre of the Bar of the LMC.