A5085792069- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Blind Source Separation Techniques
- Scientific Research and Discoveries
- SAS software applications and methods
- Spectroscopy and Laser Applications
- Crystal Structures and Properties
- Nuclear physics research studies
- Astronomical and nuclear sciences
- Solar and Space Plasma Dynamics
- Inertial Sensor and Navigation
- Spacecraft and Cryogenic Technologies
Universidad Politécnica de Madrid
2025
Universidad Complutense de Madrid
2017-2024
Hamburg Institut (Germany)
2024
Instituto de Astrofísica de Canarias
2022-2023
Hamburger Fern-Hochschule
2023
Universität Hamburg
2023
Universidad de La Laguna
2022-2023
Centro de Astrobiología
2021-2022
Max Planck Institute for Astronomy
2019
Max Planck Society
2019
The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the sample by publishing one spectrum each dwarf. These spectra cover wavelength range 520--1710nm at a resolution of least $R > 80,000$, and measure its RV, H$\alpha$ emission, projected rotation velocity. We an atlas high-resolution M-dwarf compare atmospheric models. To quantify RV precision that can be achieved in low-mass stars over range, analyze our...
We determine the radii and masses of 293 nearby, bright M dwarfs CARMENES survey. This is first time that such a large homogeneous high-resolution (R>80 000) spectroscopic survey has been used to derive these fundamental stellar parameters. derived using Stefan-Boltzmann's law. obtained required effective temperatures $T_{\rm eff}$ from spectral analysis we luminosities L integrated broadband photometry together with Gaia DR2 parallaxes. The mass was then determined mass-radius relation...
We determined effective temperatures, surface gravities, and metallicities for a sample of 343 M dwarfs observed with CARMENES, the double-channel, high-resolution spectrograph installed at 3.5 m telescope Calar Alto Observatory. employed S TE P AR YN , Bayesian spectral synthesis implementation particularly designed to infer stellar atmospheric parameters late-type stars following Markov chain Monte Carlo approach. made use BT-Settl model atmospheres radiative transfer code turbospectrum...
The CARMENES instrument was conceived to deliver high-accuracy radial velocity (RV) measurements with long-term stability search for temperate rocky planets around a sample of nearby cool stars. broad wavelength coverage designed provide range stellar activity indicators assess the nature potential RV signals and valuable spectral information help characterise targets. Data Release 1 (DR1) makes public all observations obtained during guaranteed time observations, which ran from 2016 2020...
We investigated almost 500 stars distributed among 193 binary or multiple systems made of late-F, G-, early-K primaries and late-K M dwarf companion candidates. For all them, we compiled measured coordinates, J-band magnitudes, spectral types, distances, proper motions.With these data, established a sample 192 physically bound systems. In parallel, carried out observations with HERMES/Mercator obtained high resolution spectra for the five secondaries. used automatic StePar code deriving...
The Gl 486 system consists of a very nearby, relatively bright, weakly active M3.5 V star at just 8 pc with warm transiting rocky planet about 1.3 R_Terra and 3.0 M_Terra that is ideal for both transmission emission spectroscopy testing interior models telluric planets. To prepare future studies, we collected light curves seven new transits observed the CHEOPS space mission radial velocities obtained MAROON-X/Gemini North CARMENES/Calar Alto telescopes, together previously published...
The design and construction of CARMENES has been presented at previous SPIE conferences. It is a next-generation radial-velocity instrument the 3.5m telescope Calar Alto Observatory, which was built by consortium eleven Spanish German institutions. consists two separate échelle spectrographs covering wavelength range from 0.52 to 1.71μm spec-tral resolution R < 80,000, fed fibers Cassegrain focus telescope. saw "First Light" on Nov 9, 2015. During commissioning initial operation phases, we...
Context: SteParSyn is an automatic code written in Python 3.X designed to infer the stellar atmospheric parameters Teff, log(g), and [Fe/H] of FGKM-type stars following spectral synthesis method. Aims: We present a description test its performance against sample late-type that were observed with HERMES spectrograph mounted at 1.2-m Mercator Telescope. This contains 35 targets well-known determined independently from spectroscopy. The available astronomical community GitHub repository....
Abstract We present the first elemental abundance measurements of K dwarf (K7V) exoplanet-host star WASP-107 using high-resolution ( R ≃45,000), near-infrared H - and -band) spectra taken from Gemini-S/IGRINS. use previously determined physical parameters literature infer abundances 15 elements—C, N, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Ni, all with precision < 0.1 dex—based on model fitting MARCS atmospheres Turbospectrum spectral synthesis code. Our results show near-solar a...
The main scientific goal of TESS is to find planets smaller than Neptune around stars that are bright enough allow for further characterization studies. Given our current instrumentation and detection biases, M dwarfs prime targets in the search small (or near) habitable zone their host star. In this work, we use photometric observations CARMENES radial velocity (RV) measurements validate a pair transiting planet candidates found by TESS. data were fitted simultaneously, using Bayesian...
The Gaia -ESO Survey is a public spectroscopic survey that targeted ≳10 5 stars covering all major components of the Milky Way from end 2011 to 2018, delivering its final release in May 2022. Unlike other surveys, only observed across spectral types with dedicated, specialised analyses: O ( T eff ~ 30 000–52 000 K) way K-M (≳3500 K). physics throughout these stellar regimes varies significantly, which has previously prohibited any detailed comparisons between significantly different types....
K-dwarf stars are promising targets in the exploration of potentially habitable planets. Their properties, falling between G and M dwarfs, provide an optimal trade-off prospect habitability ease detection. The KOBE experiment is a blind-search survey exploiting this niche, monitoring radial velocity 50 late-type stars. It employs CARMENES spectrograph, with observational strategy designed to detect planets zone their system. In work, we exploit data set characterize planetary signals K7V...
Context: StePar is an automatic code written in Python 3.X designed to compute the stellar atmospheric parameters Teff, log(g), [Fe/H], and of FGK-type stars by means EW method. This has already been extensively tested different spectroscopic studies with several spectrographs against myriads Gaia-ESO Survey UVES U580 spectra late-type, low-mass as one its thirteen pipelines. Aims: We describe test it a library well characterised Gaia benchmark stars. also release community provide link for...
Deriving metallicities for solar-like stars follows well-established methods, but cooler such as M dwarfs, the determination is much more complicated due to forests of molecular lines that are present. Several methods have been developed in recent years determine accurate stellar parameters these cool ($T_{\rm eff} \lesssim$ 4000 K). However, significant differences can be found at times when comparing same star derived using different methods. In this work, we effective temperatures,...
Previous studies of open clusters have shown that lithium depletion is not only strongly age dependent but also shows a complex pattern with other parameters yet understood. For pre- and main-sequence late-type stars, these include metallicity, mixing mechanisms, convection structure, rotation, magnetic activity. We perform thorough membership analysis for large number stars observed within the Gaia-ESO survey (GES) in field 20 clusters, ranging from young associations, to intermediate-age...
The detection of habitable worlds is one humanity's greatest endeavors. So far, astrobiological studies show that the most critical components for life development liquid water. Its chemical properties and its capacity to dissolve hence transport other substances makes this constituent a key piece in life. As consequence, looking as we know it directly related search For remote distant planetary systems, means planets so-called zone. In sense, K-dwarf stars are perfect hosts. Contrary...
Abstract We present an in-depth, high-resolution spectroscopic analysis of the M dwarf K2-18, which hosts a sub-Neptune exoplanet in its habitable zone. show our technique to accurately normalize observed spectrum, is crucial for proper spectral fitting. also introduce new automatic, line-by-line, model-fitting code, AutoSpecFit, performs iterative χ 2 minimization process measure individual elemental abundances cool dwarfs. apply this code star and abundance 10 elements: C, O, Na, Mg, Al,...
Existing and upcoming instrumentation is collecting large amounts of astrophysical data, which require efficient fast analysis techniques. We present a deep neural network architecture to analyze high-resolution stellar spectra predict parameters such as effective temperature, surface gravity, metallicity, rotational velocity. With this study, we firstly demonstrate the capability networks precisely recover from synthetic training set. Secondly, application method observed impact gap (i.e.,...
Aims. We present a spectroscopic analysis of the extremely luminous red star VX Sgr based on high-resolution observations combined with AAVSO light curve data. Given puzzling characteristics Sgr, we explore three scenarios for its nature: massive supergiant (RSG) or hypergiant (RHG), Thorne Zytkow object (TZO), and an extreme Asymptotic Giant Branch (AGB) star. Methods. Sampling more than one whole cycle photometric variability, derive stellar atmospheric parameters by using state-of-the-art...
(Abridged) We characterize a series of neutral vanadium atomic absorption lines in the 800--910nm wavelength region high signal-to-noise, high-resolution, telluric-corrected M-dwarf spectra from CARMENES survey. Many these are prominent and exhibit distinctive broad flat-bottom shape, which is result hyperfine structure (HFS). investigate potential implications HFS split for abundance analysis cool stars. With standard spectral synthesis routines, as provided by spectroscopy software iSpec...
The Gaia -ESO Survey is an European Southern Observatory (ESO) public spectroscopic survey that targeted 10 5 stars in the Milky Way covering major populations of disk, bulge and halo. observations were made using FLAMES on VLT obtaining both UVES high ( R ~ 47 000) GIRAFFE medium 20 resolution spectra. analysis spectra was work multiple teams (nodes) within five working groups (WG). homogenisation stellar parameters WG11 (high FGK stars) WG10 (medium described here. In cases, carried out a...