Exoplanets & Stellar Populations Group

An all-sky catalog of solar-type dwarfs for exoplanetary transit surveys

Nascimbeni et al., 2016, MNRAS, 463, 4210

Most future surveys designed to discover transiting exoplanets, including TESS and PLATO, will target bright (V < 13) and nearby solar-type stars having a spectral type later than F5. In order to enhance the probability of identifying transits, these surveys must cover a very large area on the sky, because of the intrinsically low areal density of bright targets. Unfortunately, no existing catalog of stellar parameters is both deep and wide enough to provide a homogeneous input list.
As the first Gaia data release exploitable for this purpose is expected to be released not earlier than late 2017, we have devised an improved reduced-proper-motion method to discriminate late field dwarfs and giants by combining UCAC4 proper motions with APASS DR6 photometry, and relying on RAVE DR4 as an external calibrator.

The output, named UCAC4-RPM, is a publicly-available, complete all-sky catalog of solar-type dwarfs down to V < 13.5, plus an extension to log g > 3.0 subgiants. The relatively low amount of contamination (defined as the fraction of false positives; < 30%) also makes UCAC4-RPM a useful tool for the past and ongoing ground-based transit surveys, which need to discard candidate signals originating from early-type or giant stars. As an application, we show how UCAC4-RPM may support the preparation of the TESS (that will map almost the entire sky) input catalog and the input catalog of PLATO (within the research area Field and target characterisation and selection), planned to survey more than half of the whole sky with exquisite photometric precision.

The UCAC4-ROM catalog is available on Vizier at CDS at this link or downloadable here (gzipped file, 340M).