RR Lyrae stars and novae in the Magellanic Clouds.

RR Lyrae variable stars and classical novae can be used very effectively for locating and studying the old stellar populations in the Magellanic Clouds. RR Lyrae stars are found in large numbers in both Clouds at about 19m. Apart from the concentrated searches within Cloud clusters, intensive surveys for field variables have so far been made in four areas, each about 1 deg square. Novae have the advantage of being as bright as 10m at maximum light. They can be detected with small telescopes, and surveys have covered almost the entire area of each Cloud. Needs and prospects for future surveys are discussed. Both types of object are suitable for investigating the early chemical composition of the Clouds and its subsequent enrichment with heavy elements. Studies of the old populations in the Clouds are reinforcing the view that, while some stars in the Magellanic Clouds are as old as any in the Galaxy, the major bursts of star formation came along comparatively recently.