EDDINGTON AND STELLAR-ROTATION STUDIES: LIGHT CURVE ANALYSIS TOOLS AND GROUND-BASED FOLLOW-UP SPECTROSCOPY

摘要

Eddirigton will produce a data stream of light curves for some tens of thousands of stars. This means that a clever algorithm must predetermine what type of variability is expected for a particular target, and then suggest and apply the proper analysis tool. We investigate the feasibility of such an algorithm by comparing the chances of detecting the solar rotational period from the long-term Sun-as-a-star ACRIM data by means of Fourier and wavelet period-search techniques. We first create artificial data with a spot-modelling code that includes differential surface rotation, and then try to recover the rotation signal from the Fourier spectrum. Then, we present the example of the rapidly-rotating spotted star UZ Librae, where ground-based time-series photometry obtained with automatic telescopes indeed revealed signal from a differentially rotating stellar, surface. Finally, we discuss the urgent need for ground-based preparatory and follow-up spectroscopy and introduce our own support possibilities. We emphasise that all proposed joint Eddington-support efforts, with our Spanish colleagues on the Canary islands and our Italian and American colleagues in Arizona, strongly suggest that the planet-finding field is in the northern hemisphere.