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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Wide companions to M and L subdwarfs with Gaia and the Virtual ObservatoryAims: The aim of the project is to identify wide common proper motion companions to a sample of spectroscopically confirmed M and L metal-poor dwarfs (also known as subdwarfs) to investigate the impact of metallicity on the binary fraction of low-mass metal-poor binaries and to improve the determination of their metallicity from the higher-massGonzález-Payo, J. et al.
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62021 -
The CARMENES search for exoplanets around M dwarfs. Mapping stellar activity indicators across the M dwarf domainContext. Stellar activity poses one of the main obstacles for the detection and characterisation of small exoplanets around cool stars, as it can induce radial velocity (RV) signals that can hide or mimic the presence of planetary companions. Several indicators of stellar activity are routinely used to identify activity-related signals in RVs, butLafarga, M. et al.
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82021 -
HADES RV programme with HARPS-N at TNG. XIV. A candidate super-Earth orbiting the M-dwarf GJ 9689 with a period close to half the stellar rotation periodContext. It is now well-established that small, rocky planets are common around low-mass stars. However, the detection of such planets is challenged by the short-term activity of host stars. Aims: The HARPS-N red Dwarf Exoplanet Survey programme is a long-term project at the Telescopio Nazionale Galileo aimed at monitoring nearby, early-type, MMaldonado, J. et al.
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72021 -
Simultaneous photometric and CARMENES spectroscopic monitoring of fast-rotating M dwarf GJ 3270. Discovery of a post-flare corotating featureContext. Active M dwarfs frequently exhibit large flares, which can pose an existential threat to the habitability of any planet in orbit in addition to making said planets more difficult to detect. M dwarfs do not lose angular momentum as easily as earlier-type stars, which maintain the high levels of stellar activity for far longer. StudyingJohnson, E. N. et al.
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72021 -
The CARMENES search for exoplanets around M dwarfs. Two terrestrial planets orbiting G 264-012 and one terrestrial planet orbiting Gl 393We report the discovery of two planetary systems, namely G 264-012, an M 4.0 dwarf with two terrestrial planets (M b sin i=2.50 −0.30 +0.29 M ⊕ and M c sin i=3.75 −0.47 +0.48 M ⊕), and Gl 393, a bright M 2.0 dwarf with one terrestrial planet (M b sini = 1.71 ± 0.24M ⊕). Although both stars were proposed to belong to young stellar kinematic groupsAmado, P. J. et al.
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62021 -
An ultra-short-period transiting super-Earth orbiting the M3 dwarf TOI-1685Dynamical histories of planetary systems, as well as the atmospheric evolution of highly irradiated planets, can be studied by characterizing the ultra-short-period planet population, which the TESS mission is particularly well suited to discover. Here, we report on the follow-up of a transit signal detected in the TESS sector 19 photometric timeBluhm, P. et al.
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62021 -
ESPRESSO mass determination of TOI-263b: an extreme inhabitant of the brown dwarf desertThe TESS mission has reported a wealth of new planetary systems around bright and nearby stars amenable for detailed characterizations of planet properties and atmospheres. However, not all interesting TESS planets orbit around bright host stars. TOI-263 b is a validated ultra-short-period substellar object in a 0.56-day orbit around a faint (V =Palle, E. et al.
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62021 -
Mass and density of the transiting hot and rocky super-Earth LHS 1478 b (TOI-1640 b)One of the main objectives of the Transiting Exoplanet Survey Satellite (TESS) mission is the discovery of small rocky planets around relatively bright nearby stars. Here, we report the discovery and characterization of the transiting super-Earth planet orbiting LHS 1478 (TOI-1640). The star is an inactive red dwarf (J ~ 9.6 mag and spectral typeSoto, M. G. et al.
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52021 -
HADES RV Programme with HARPS-N at TNG. XIII. A sub-Neptune around the M dwarf GJ 720 AContext. The high number of super-Earth and Earth-like planets in the habitable zone detected around M-dwarf stars in recent years has revealed these stellar objects to be the key to planetary radial velocity (RV) searches. Aims: Using the HARPS-N spectrograph within The HArps-n red Dwarf Exoplanet Survey (HADES) we have reached the precisionGonzález-Álvarez, E. et al.
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52021 -
Weighing stars from birth to death: mass determination methods across the HRDThe mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exist a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginningSerenelli, Aldo et al.
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122021 -
A transmission spectrum of the planet candidate WD 1856+534 b and a lower limit to its massThe cool white dwarf WD 1856+534 was found to be transited by a Jupiter-sized object with a mass at or below 14 M Jup. We used the GTC telescope to obtain and analyse the photometry and low-resolution spectroscopy of six transits of WD 1856+534 b, with the intention of deriving the slope of the transmission spectrum. Such a slope, assuming a cloudAlonso, R. et al.
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52021 -
The CARMENES search for exoplanets around M dwarfs. No evidence for a super-Earth in a 2-day orbit around GJ 1151Context. The interaction between Earth-like exoplanets and the magnetic field of low-mass host stars are considered to produce weak emission signals at radio frequencies. A study using LOFAR data announced the detection of radio emission from the mid M-type dwarf GJ 1151 that could potentially arise from a close-in terrestrial planet. Recently, theRibas, I. et al.
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52021 -
Six transiting planets and a chain of Laplace resonances in TOI-178Determining the architecture of multi-planetary systems is one of the cornerstones of understanding planet formation and evolution. Resonant systems are especially important as the fragility of their orbital configuration ensures that no significant scattering or collisional event has taken place since the earliest formation phase when the parentLeleu, A. et al.
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52021 -
A sub-Neptune and a non-transiting Neptune-mass companion unveiled by ESPRESSO around the bright late-F dwarf HD 5278 (TOI-130)Context. Transiting sub-Neptune-type planets, with radii approximately between 2 and 4 R ⊕, are of particular interest as their study allows us to gain insight into the formation and evolution of a class of planets that are not found in our Solar System. Aims: We exploit the extreme radial velocity (RV) precision of the ultra-stable echelleSozzetti, A. et al.
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42021 -
A super-Earth on a close-in orbit around the M1V star GJ 740. A HADES and CARMENES collaborationContext. M-dwarfs have proven to be ideal targets for planetary radial velocity (RV) searches due to their higher planet-star mass contrast, which favors the detection of low-mass planets. The abundance of super-Earth and Earth-like planets detected around this type of star motivates further such research on hosts without reported planetaryToledo-Padrón, B. et al.
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42021 -
Exploring the planetary-mass population in the Upper Scorpius associationWe aim at identifying very low-mass isolated planetary-mass member candidates in the nearest OB association to the Sun, Upper Scorpius (USco) (145 pc; 5-10 Myr), to constrain the form and shape of the luminosity function and mass spectrum in this regime. We conducted a deep multiband (Y = 21.2, J = 20.5, Z = 22.0 mag) photometric survey of 6 deg 2Lodieu, N. et al.
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52021 -
A nearby transiting rocky exoplanet that is suitable for atmospheric investigationSpectroscopy of transiting exoplanets can be used to investigate their atmospheric properties and habitability. Combining radial velocity (RV) and transit data provides additional information on exoplanet physical properties. We detect a transiting rocky planet with an orbital period of 1.467 days around the nearby red dwarf star Gliese 486. TheTrifonov, T. et al.
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32021 -
The atmosphere of HD 209458b seen with ESPRESSO. No detectable planetary absorptions at high resolutionWe observed two transits of the iconic gas giant HD 209458b between 380 and 780 nm, using the high-resolution ESPRESSO spectrograph. The derived planetary transmission spectrum exhibits features at all wavelengths where the parent star shows strong absorption lines, for example, Na I, Mg I, Fe I, Fe II, Ca I, V I, Hα, and K I. We interpreted theseCasasayas-Barris, N. et al.
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32021 -
Fundamental physics with ESPRESSO: Towards an accurate wavelength calibration for a precision test of the fine-structure constantObservations of metal absorption systems in the spectra of distant quasars allow one to constrain a possible variation of the fine-structure constant throughout the history of the Universe. Such a test poses utmost demands on the wavelength accuracy and previous studies were limited by systematics in the spectrograph wavelength calibration. ASchmidt, Tobias M. et al.
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22021 -
ESPRESSO high-resolution transmission spectroscopy of WASP-76 bAims: We report on ESPRESSO high-resolution transmission spectroscopic observations of two primary transits of the highly irradiated, ultra-hot Jupiter-sized planet, WASP-76b. We investigated the presence of several key atomic and molecular features of interest that may reveal the atmospheric properties of the planet. Methods: We extracted twoTabernero, H. M. et al.
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22021
