J. A. Caballero's Humboldt-Foundation Research Stay in Germany Renewed "Blaue Erden bei roten Zwergen" – Heidelberg, Göttingen, Hamburg, Tautenburg CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs, http://carmenes.caha.es/) is a next-generation instrument being built for the Zeiss 3.5 m telescope at the Calar Alto Observatory (Andalusia, Spain) by a consortium of German and Spanish institutions. In plain English, it is a complex machine to look for planets like our Earth around close, small, red stars, dubbed M dwarfs. In detail, CARMENES consists of two separated spectrographs covering the wavelength ranges from 0.5 to 1.0 µm and from 1.0 to 1.7 µm with spectral resolutions R = 82,000, each of which shall perform high-accuracy radial-velocity measurements (∼1 m s-1) with long-term stability. The fundamental science objective of CARMENES is to carry out a radial-velocity survey of ∼300 late-type mainsequence stars with the goal of detecting low-mass planets in their habitable zones. We aim at being able to detect 2 MEarth planets in the habitable zone of M5V stars. Habitable planets have liquid water on their surfaces and are expected to be blue, which explains the title of this research project: “Blue earths near red dwarfs”. The CARMENES first light is expected to occur in Summer 2015. The consortium that builds CARMENES is made of the Max-PlanckInstitut für Astronomie Heidelberg, Landessternwarte Königstuhl Heidelberg, Institut für Astrophysik Göttingen, Thüringer Landessternwarte Tautenburg and Hamburger Sternwarte, together with the Observatory of Calar Alto and five research institutions and universities in Spain. In total, we are about 130 researchers and engineers in Germany and Spain. Dr. Caballero is the CARMENES deputy project manager, communication manager, webmaster, leader of the data work package, and responsible of numerous managerial, engineering, and scientific tasks. Only a few months ahead of the first tests at the Observatory, and less than a year ahead of the start of the survey, it becomes critical to define the list of M dwarfs that CARMENES will observe. One of the main Dr. Caballero’s scientific tasks is to coordinate the preparation of the CARMENES input catalogue, which is a comprehensive, exhaustive compilation of M dwarfs and stellar data from which the CARMENES science team will carefully choose the best, brightest, latest, slowest-rotator, single, M-dwarf targets. An incorrect star choice translates into lower probabilities of discovering new exoearths. CARMENCITA, the CARMENES Cool star Information and daTa Archive, is that M-dwarf database from where we will choose our best target sample. CARMENCITA currently catalogues over 2200 M dwarfs visible from the Calar Alto Observatory. For each star, we tabulate dozens of parameters compiled from the literature or measured by us with new data, such as: accurate astrometry, spectral typing, photometry in 20 bands from the ultraviolet to the mid-infrared, rotational and radial velocities, X-ray count rates and hardness ratios, close and wide multiplicity data, basic stellar parameters derived from sythetic model fits, etc. It is being continuously updated with the most precise parameters. The private on-line catalogue, including preparatory science observations (i.e., high-resolution imaging, lowand high-resolution spectroscopy), will be eventually public as a CARMENES legacy and will represent a worldwide cornerstone in the investigation of cool stars in the solar neighbourhood. While the CARMENCITA data compilation is centralized at the Dr. Caballero’s location in Madrid, key parts of the analysis are also distributed among the other institutions involved in CARMENES, both in Spain and Germany. The aim of this proposal for a HumboldtFoundation Renewed Research Stay in Germany is to allow Dr. Caballero to complete the best CARMENES input catalogue in close collaboration with colleagues at the five German centres: • Institut für Astrophysik Göttingen (host: Prof. A. Reiners). Maximum priority will be given to the analysis, interpretation and publication of the preparatory high-resolution spectra obtained with telescopes in Chile, Spain and USA, and the study of stellar activity. • Landessternwarte Königstuhl Heidelberg (host: Prof. A. Quirrenbach). Work will be focused on the CARMENCITA visual interface of the “golden sample”, i.e. the stars that today have the highest chances to be observed. • Hamburger Sternwarte (host: Prof. J. H. M. M. Schmidt). Efforts will be devoted to create the largest compendium of M dwarfs with X-ray emission from ROSAT data, which will be in turn an excellent input catalogue for eROSITA. • Max-Planck-Institut für Astronomie (host: Prof. R. Mundt). We will draw a plan on how to maximize the synergies between the Planet and Star Formation group at MPIA and the CARMENES consortium for the science exploitation phase. • Thüeringer Landessternwarte Tautenburg (host: Dr. E. W. Guenther). We will investigate how the tools and instruments used successfully in radial-velocity monitoring by the TLS team can be implemented in parallel to the CARMENES survey. This is a step-by-step process that cannot be accomplished in a single stay, but in five dedicated stays approximately in the same order as listed. For preparing the next step, a gap between two consecutive stays of about one month is needed. Because of Dr. Caballero’s commitmments (CARMENES deputy project manager, supervisor of PhD students and lecturer of master courses in Madrid, member in international boards), each stay will be one week long (from Monday morning to Friday afternoon). Such relatively short stays have the benefit of maximizing efficiency and minimizing travel expenses, but force to have a well pre-defined stay schedule. In the case of the stay at the Institut für Astrophysik Göttingen with Prof. A. Reiners, Prof. S. Dreizler, Dr. S. V. Jeffers, Dr. U. Lemke, Dr. M. Zechmeister, F. Bauer, A. Lamert, C. Marvin, V.-M. Passegger, L.-F. Sarmiento and S. Schäfer, the main Dr. Caballero’s tasks will be to check: • Status of the reduction and preliminary analysis of all the FEROS, CAFÉ and HRS spectra (he coordinated the observations in Chile and Spain). • Target coordinates and names and to help preparing a log-table of observations. • Derived spectral types, and to compare with previous measurements and look for outliers. • Derived rotational velocities, and to compare with previous measurements, help plotting them versus rotation periods and activity indicators (Hα pseudo-equivalent width, X-ray flux) and help defining a spectral type-dependent vsini upper limit for CARMENES selection. • Derived effective temperatures, surface gravities and metallicities, and to compare with spectral indices sensitive to those parameters (e.g., TiO5 bands, Na doublet, zeta index), look for outliers and help with interpretation. • Single-epoch and multi-epoch radial velocities and draw a plan on how to use them for making a comprehensive kinematics analysis. • Derived Hα pseudo-equivalent widths, and to study the accretion-chromosphere emission boundary and Hα variability in multi-epoch observations. • In-preparation manuscripts for the Astronomy & Astrophysics journal on the analysis of the high-resolution spectra, or to edit or help editing them. • Status of the automatic data pipeline development (a piece of software needed since the CARMENES first light). • Status of the NIR+VIS Fabry-Pérot etalon (a piece of hardware needed for an accurate wavelength calibration of the CARMENES spectra). Dr. Caballero will be working with F. Bauer, A. Lamert, C. Marvin, V.-M. Passegger, L.-F. Sarmiento and S. Schäfer to provide them with information that they will need for their PhD theses.
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