Start year
1995
Organizational Unit
Organizing institutions
General
Description
Our goal is to study the processes that lead to the formation of low mass stars, brown dwarfs and planets and to characterize the physical properties of these objects in various evolutionary stages. Low mass stars and brown dwarfs are likely the most numerous type of objects in our Galaxy but due to their low intrinsic luminosity they are not so well known. We aim to study the frequency, multiplicity and spatial distribution of these objects in the solar neighbourhood and in nearby star forming regions and stellar clusters in order to better understand the mechanism of formation, characterise their optical and infrared properties and establish the relation between spectral properties, mass and luminosity.. Most of our effort will be dedicated to push toward lower mass limits the detection of these astros either bounded to stars and brown dwarfs and/or free-floating in interstellar space. The lowest mass objects display a lower intrinsic luminosity and cooler effective temperatures thus they are remarkably difficult to detect using direct imaging techniques. However, these techniques allow a full photometric and spectroscopic characterization and a best determination of their physical and chemical properties. We also aim to investigate the presence of planets around low mass stars using radial velocity measurements and techniques for high spatial resolution imaging. We will develop ultrastable spectrographs for large telescopes and systems for ultrafast imaging. With the spectrographs it would be possible to detect planets of similar mass to the Earth around G, K and M-type stars. The goal is to establish the frequency of these planets in stars of the solar neighbourhood and characterise the properties of the associated planetary systems.
Members
Principal investigator
Prof.
Rafael
Rebolo López
Project staff
Víctor Javier
Sánchez Bejar
Nicolas Cédric
Lodieu
Jonay Isai
González Hernández
Patricia
Chinchilla Gallego
Collaborators
Dr.
M.R. Zapatero Osorio
Dr.
A. Pérez-Garrido
Dr.
I. Villo
Dr.
A. Díaz Sánchez
Dr.
E. Jodar
Dr.
C. McKay
Dr.
D. King
Dr.
T. Henning
Dr.
R. Mundt
Dr.
G. Bihain
Dr.
P. Lucas
Dr.
D. Pinfield
Dr.
H. Jones
Dr.
F. Marocco
Dr.
M.T. Ruiz
Dr.
L. Labadie
Dr.
Ya. Pavlenko
Dr.
R. Smart
Dr.
A. Burgasser
Dr.
F. Allard
Dr.
R. Raddi
Results
- The optical and near-infrared sequence of 10 Myr-old L dwarfs in the nearest OB association to the Sun, Upper Scorpius
- The lithium depletion boundary of the Hyades cluster.
Scientific activity
Related publications
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Gliese 49: activity evolution and detection of a super-Earth. A HADES and CARMENES collaborationContext. Small planets around low-mass stars often show orbital periods in a range that corresponds to the temperate zones of their host stars which are therefore of prime interest for planet searches. Surface phenomena such as spots and faculae create periodic signals in radial velocities and in observational activity tracers in the same range, soPerger, M. et al.
Advertised on:
42019 -
MuSCAT2: four-color simultaneous camera for the 1.52-m Telescopio Carlos SánchezWe report the development of a four-color simultaneous camera for the 1.52-m Telescopio Carlos Sánchez in the Teide Observatory, Canaries, Spain. The instrument, named MuSCAT2, has a capability of four-color simultaneous imaging in g (400 to 550 nm), r (550 to 700 nm), i (700 to 820 nm), and zs (820 to 920 nm) bands. MuSCAT2 equips four 1024 × 1024Narita, N. et al.
Advertised on:
12019 -
The CARMENES search for exoplanets around M dwarfs. Chromospheric modeling of M 2-3 V stars with PHOENIXChromospheric modeling of observed differences in stellar activity lines is imperative to fully understand the upper atmospheres of late-type stars. We present one-dimensional parametrized chromosphere models computed with the atmosphere code PHOENIX using an underlying photosphere of 3500 K. The aim of this work is to model chromospheric lines ofHintz, D. et al.
Advertised on:
32019 -
The CARMENES search for exoplanets around M dwarfs. Period search in Hα, Na I D, and Ca II IRT linesWe use spectra from CARMENES, the Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs, to search for periods in chromospheric indices in 16 M0-M2 dwarfs. We measure spectral indices in the Hα, the Ca II infrared triplet (IRT), and the Na I D lines to study which of these indices areFuhrmeister, B. et al.
Advertised on:
32019 -
A 3D view of the Hyades stellar and sub-stellar populationAims: Our scientific goal is to provide a 3D map of the nearest open cluster to the Sun, the Hyades, combining the recent release of Gaia astrometric data, ground-based parallaxes of sub-stellar member candidates and photometric data from surveys which cover large areas of the cluster. Methods: We combined the second Gaia release with ground-basedLodieu, N. et al.
Advertised on:
32019 -
The CARMENES search for exoplanets around M dwarfs. Activity indicators at visible and near-infrared wavelengthsContext. The Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs (CARMENES) survey is searching for Earth-like planets orbiting M dwarfs using the radial velocity method. Studying the stellar activity of the target stars is important to avoid false planet detections and to improve ourSchöfer, P. et al.
Advertised on:
32019 -
The CARMENES search for exoplanets around M dwarfs. The enigmatic planetary system GJ 4276: one eccentric planet or two planets in a 2:1 resonance?We report the detection of a Neptune-mass exoplanet around the M4.0 dwarf GJ 4276 (G 232-070) based on radial velocity (RV) observations obtained with the CARMENES spectrograph. The RV variations of GJ 4276 are best explained by the presence of a planetary companion that has a minimum mass of mb sin i ≈ 16 M⊕ on a Pb = 13.35 day orbit. The analysisNagel, E. et al.
Advertised on:
22019 -
Multiple water band detections in the CARMENES near-infrared transmission spectrum of HD 189733 bAims: We explore the capabilities of CARMENES for characterising hot-Jupiter atmospheres by targeting multiple water bands, in particular, those at 1.15 and 1.4 μm. Hubble Space Telescope observations suggest that this wavelength region is relevant for distinguishing between hazy and/or cloudy and clear atmospheres. Methods: We observed one transitAlonso-Floriano, F. J. et al.
Advertised on:
12019 -
CARMENES input catalogue of M dwarfs. IV. New rotation periods from photometric time seriesAims: The main goal of this work is to measure rotation periods of the M-type dwarf stars being observed by the CARMENES exoplanet survey to help distinguish radial-velocity signals produced by magnetic activity from those produced by exoplanets. Rotation periods are also fundamental for a detailed study of the relation between activity andDíez Alonso, E. et al.
Advertised on:
12019 -
Detection of He I λ10830 Å absorption on HD 189733 b with CARMENES high-resolution transmission spectroscopyWe present three transit observations of HD 189733 b obtained with the high-resolution spectrograph CARMENES at Calar Alto. A strong absorption signal is detected in the near-infrared He I triplet at 10830 Å in all three transits. During mid-transit, the mean absorption level is 0.88 ± 0.04% measured in a ±10 km s-1 range at a net blueshift of - 3Salz, M. et al.
Advertised on:
122018 -
Exploring the substellar population in the Hyades open clusterAims: Our aim is to identify substellar members of the nearby Hyades open star cluster to determine the photometric and spectroscopic properties of brown dwarfs at moderately old ages and extend our knowledge of the substellar mass function of the cluster. Methods: We cross-matched the 2MASS and WISE public catalogues and measured proper motions toPérez-Garrido, A. et al.
Advertised on:
122018 -
The CARMENES search for exoplanets around M dwarfs. The warm super-Earths in twin orbits around the mid-type M dwarfs Ross 1020 (GJ 3779) and LP 819-052 (GJ 1265)We announce the discovery of two planetary companions orbiting around the low-mass stars Ross 1020 (GJ 3779, M4.0V) and LP 819-052 (GJ 1265, M4.5V). The discovery is based on the analysis of CARMENES radial velocity (RV) observations in the visual channel as part of its survey for exoplanets around M dwarfs. In the case of GJ 1265, CARMENESLuque, R. et al.
Advertised on:
122018 -
A candidate super-Earth planet orbiting near the snow line of Barnard's starBarnard's star is a red dwarf, and has the largest proper motion (apparent motion across the sky) of all known stars. At a distance of 1.8 parsecs1, it is the closest single star to the Sun; only the three stars in the α Centauri system are closer. Barnard's star is also among the least magnetically active red dwarfs known2,3 and has an estimatedRibas, I. et al.
Advertised on:
112018 -
The CARMENES search for exoplanets around M dwarfs. Nine new double-line spectroscopic binary starsContext. The CARMENES spectrograph is surveying ˜300 M dwarf stars in search for exoplanets. Among the target stars, spectroscopic binary systems have been discovered, which can be used to measure fundamental properties of stars. Aims: Using spectroscopic observations, we determine the orbital and physical properties of nine new double-lineBaroch, D. et al.
Advertised on:
112018 -
CARMENES: high-resolution spectra and precise radial velocities in the red and infraredThe design and construction of CARMENES has been presented at previous SPIE conferences. It is a next-generation radial-velocity instrument at the 3.5m telescope of the Calar Alto Observatory, which was built by a consortium of eleven Spanish and German institutions. CARMENES consists of two separate échelle spectrographs covering the wavelengthQuirrenbach, A. et al.
Advertised on:
72018 -
GTC adaptive optics first performance tests in laboratoryThe GTC AO system designed and developed during the last years is based on a single deformable mirror with 21 x 21 actuators, conjugated to the telescope pupil, and a Shack-Hartmann wavefront sensor with 20 x 20 subapertures, using an OCAM2 camera. The GTCAO system will provide a corrected beam with a Strehl Ratio (SR) of 0.65 in K-band with brightReyes García-Talavera, M. et al.
Advertised on:
72018 -
Servo control simulations and preliminary laboratory results for GTC adaptive optics with NGSThe Gran Telescopio Canarias Adaptive Optics (GTCAO) is a single-conjugated post-focal system with a Shack Hartmann wavefront sensor, and one Deformable Mirror (DM) conjugated to the pupil. The optical design for tip-tilt correction includes two different mirrors, DM and the telescope M2, being M2 also used for off-loading the DM to avoid reachingNúñez Cagigal, Miguel et al.
Advertised on:
72018 -
EMCCD in-situ periodic characterization in Shack-Hartmann wavefront sensor for GTCAOThe Gran Telescopio Canarias Adaptive Optics (GTCAO) will measure the wavefront with a Shack-Hartmann sensor. This wavefront sensor (WFS) is based on the CCD220, an electron-multiplying CCD (EMCCD) that achieves sub-electron readout noise, increasing the signal to noise ratio when weak natural guide stars (NGS) are used as reference. GTCAO willTubío Araújo, Óscar et al.
Advertised on:
72018 -
GTCAO real time AO closed loop software implementation and initial computer performance analysisThe Gran Telescopio Canarias Adaptive Optics (GTCAO) is a single-conjugated post-focal system with a Shack Hartmann wavefront sensor working at visible wavelength and one Deformable Mirror (DM) conjugated to the pupil. GTCAO does not include a fast tip-tilt mirror in its optical bench so it relies on the telescope secondary mirror (M2) to correctMarco de la Rosa, J. et al.
Advertised on:
72018 -
The CARMENES search for exoplanets around M dwarfs. A Neptune-mass planet traversing the habitable zone around HD 180617Despite their activity, low-mass stars are of particular importance for the search of exoplanets by the means of Doppler spectroscopy, as planets with lower masses become detectable. We report on the discovery of a planetary companion around HD 180617, a bright (J = 5.58 mag), low-mass (M = 0.45M⊙) star of spectral type M2.5 V. The star, located atKaminski, A. et al.
Advertised on:
102018
