The all-sky PLATO input catalogue

Abstract

Context. The ESA PLAnetary Transits and Oscillations of stars (PLATO) mission will search for terrestrial planets in the habitable zone of solar-type stars. Because of telemetry limitations, PLATO targets need to be pre-selected. Aims. In this paper, we present an all sky catalogue that will be fundamental to selecting the best PLATO fields and the most promising target stars, deriving their basic parameters, analysing the instrumental performances, and then planing and optimising follow-up observations. This catalogue also represents a valuable resource for the general definition of stellar samples optimised for the search of transiting planets. Methods. We used Gaia Data Release 2 (DR2) astrometry and photometry and 3D maps of the local interstellar medium to isolate FGK (V≤13) and M (V≤16) dwarfs and subgiant stars. Results. We present the first public release of the all-sky PLATO Input Catalogue (asPIC1.1) containing a total of 2 675 539 stars including 2 378 177 FGK dwarfs and subgiants and 297 362 M dwarfs. The median distance in our sample is 428 pc for FGK stars and 146 pc for M dwarfs, respectively. We derived the reddening of our targets and developed an algorithm to estimate stellar fundamental parameters (T eff , radius, mass) from astrometric and photometric measurements. Conclusions. We show that the overall (internal+external) uncertainties on the stellar parameter determined in the present study are ∼230 K (4%) for the effective temperatures, ∼0.1 R (9%) for the stellar radii, and ∼0.1 M (11%) for the stellar mass. We release a special target list containing all known planet hosts cross-matched with our catalogue.

The PLATO field selection process I. Identification and content of the long-pointing fields

“…The present work is the first attempt to identify the LOP fields using a consistent and quantitative approach. The coordinates of SOP/LOP fields previously selected, as reported in some papers (such as Nascimbeni et al 2016;Miglio et al 2017;Marchiori et al 2019;Montalto et al 2021), all centered at Galactic latitude |b| = 30 • , were merely a working hypothesis to verify their compliance with the PLATO Science Requirements Document (SRD; v8.0). The definitive choice for the first observing field will be formally delivered two years before launch with possibility of a fine tuning of the target list up to nine months before launch.…”

“…Due to telemetry constraints, PLATO will not be able to download time series of full-frame images. Rather, it will download light curves of pre-selected targets, and "imagettes" for a fraction of them, drawn from the PLATO Input Catalog (PIC; Montalto et al 2021). This implies, as it will be further discussed in Section 3, that any field-level prioritization scheme must be based on a target-level scheme.…”

“…While the PIC will contain only the targets to be observed by PLATO on the final LOP/SOP fields, an all-sky version of it, including all the stars compliant with the P1-P2-P4-P5 definition (except the requirements on photometric noise) is also available (asPIC; Montalto et al 2021) and will be the starting point of our simulations. Additional catalogues are being compiled in parallel for operational purposes (including instrumental calibration, validation, and fine pointing).…”

“…The PLATO scientific requirements for the PIC are described in the SRD for the samples mentioned above; we refer the reader to Montalto et al (2021) for a detailed overview 4 . Throughout this work, we will mostly focus on prioritizing the P1 sample because it is recognized as the "backbone of the PLATO mission and must be considered as the highest priority objective" (SRD), and the field choice should consequently be driven by it.…”

“…in which R can be extracted from the All-Sky PLATO Input Catalog (asPIC; Montalto et al 2021), where all the basic astrophysical parameters for every eligible P1-P2-P4-P5 target in the sky are homogeneously extracted from Gaia DR2 astrometry and photometry combined with interstellar extinction maps. To give a reliable estimate of the photometric error σ (equivalently called Noise-to-Signal Ratio, or NSR 7 ), on the other hand, requires a detailed modeling of the optical/electronic performances of PLATO to 1) compute the FOV footprint corresponding to a given PF pointing, and 2) estimate σ for each asPIC entry, according to its magnitude in the PLATO photometric band 8 and its position in the optical FOV and on the CCD detector of each camera.…”