New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit

By Isabelle Baraffe, Derek Homeier, G. Chabrier. 2015

1,182 citations recorded by the source corpus.

We present new models for low-mass stars down to the hydrogen-burning limit that consistently couple atmosphere and interior structures, thereby superseding the widely used BCAH98 models. The new models include updated molecular linelists and solar abundances, as well as atmospheric convection parameters calibrated on 2D/3D radiative hydrodynamics simulations. Comparison of these models with observations in various colour-magnitude diagrams for various ages shows significant improvement over previous generations of models. The new models can solve flaws that are present in the previous ones, such as the prediction of optical colours that are too blue compared to M dwarf observations. They can also reproduce the four components of the young quadruple system LkCa 3 in a colour-magnitude diagram with one single isochrone, in contrast to any presently existing model. In this paper we also highlight the need for consistency when comparing models and observations, with the necessity of using evolutionary models and colours based on the same atmospheric structures.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/79c6d9a244d010f9f3443389a44ec46d2c9fb4e3

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. B. Bowler
2. Michael C. Liu
3. Jon Fortney
4. N. Madhusudhan
5. A. Kraus
6. Eric Mamajek
7. K. Luhman
8. T. Dupuy

In Instrumentation

1. B. Bowler
2. Jon Fortney
3. Eric Mamajek
4. Michael C. Liu
5. M. Marley
6. A. Mann
7. P. Capak
8. T. Dupuy

Citations in the corpus

• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics from 10 to 100 au (2019, methodology): “We utilize the CIFIST2011 BT-Settl atmosphere models (Caffau et al. 2011; Allard 2014; Baraffe et al. 2015)45, tied to the COND “hot-start” evolutionary model grid (Baraffe et al. 2003), to give absolute H magnitude and temperature as a function of mass and age.”
• Compact Disks in a High-resolution ALMA Survey of Dust Structures in the Taurus Molecular Cloud (2019, methodology): “…and age of each source in our sample and in the Taurus disk sample of Andrews et al. (2013) are then calculated by comparing the temperature and updated luminosity to Baraffe et al. (2015) and non-magnetic Feiden (2016) models of pre-main sequence stellar evolution, as in Pascucci et al. (2016).”
• Imaging Extrasolar Giant Planets (2016, background): “For example, evolutionary models predict the H-band contrast between a 5 MJup planet orbiting a 1 M⊙ star to be ≈25 mag at 5 Gyr but only ≈10 mag at 10 Myr (Baraffe et al. 2003; Baraffe et al. 2015).”
• The star formation history and accretion-disc fraction among the K-type members of the Scorpius–Centaurus OB association (2016, methodology): “Masses and radii for the eclipsing binary UScoCTIO 5 from Kraus et al. (2015), when compared to the Baraffe et al. (2015) evolutionary models, already provide some concordance with the older ∼10 Myr ages from the F- and G-type stars, though more theoretical work remains to be completed.”
• Accretion onto Pre-Main-Sequence Stars (2016, methodology): “The two green long-dashed curves are isochrones at 1 and 10 Myr from Baraffe et al. (2015). www.annualreviews.org • Accretion onto Pre-Main-Sequence Stars 171 A nn u.”
• Individual Dynamical Masses of Ultracool Dwarfs (2017, background): “…based on theoretical work over the last two decades (e.g., Saumon et al. 1994; Baraffe et al. 1995; Burrows et al. 1997; Chabrier & Baraffe 1997; Lodders 1999; Chabrier et al. 2000; Burrows et al. 2001; Baraffe et al. 2003; Saumon & Marley 2008; MacDonald & Mullan 2009; Baraffe et al. 2015).”
• The habitability of Proxima Centauri b. I. Irradiation, rotation and volatile inventory from formation to the present (2016, methodology): “We used the evolutionary tracks provided by Baraffe et al. (2015) in order to reproduce these values at the age of the star (4.8 Gyr).”
• Why do protoplanetary disks appear not massive enough to form the known exoplanet population? (2018, background): “…from Alcalá et al. (2017) and Manara et al. (2017) to the new distances, and by comparing the new stellar luminosities and the effective temperatures of the stars with the evolutionary models by Baraffe et al. (2015), when possible, or Siess et al. (2000) for stellar masses higher than 1.4 M .”
• The Habitability of Planets Orbiting M-dwarf Stars (2016, background): “M-dwarf stars have an extended pre-main sequence (PMS) phase (Baraffe et al., 1998, 2015)—the period of time prior to settling onto the Main Sequence to begin hydrogen fusion in their cores.”
• X-shooter spectroscopy of young stellar objects in Lupus (2017, methodology): “The three stars are within the bounded region predicted by the Bildsten et al. (1997) analysis, but both masses and ages from Baraffe et al. (2015) models are discrepant when compared to the nuclear masses and ages.”
• An ALMA Survey of Protoplanetary Disks in the σ Orionis Cluster (2017, methodology): “Stellar masses taken from the literature were derived using the Siess et al. (2000) evolutionary tracks for all regions except Chamaeleon I, which used the Baraffe et al. (2015) models; the stellar masses derived using these two grids are generally consistent, thus any effects should be negligible.”
• A STEEPER THAN LINEAR DISK MASS–STELLAR MASS SCALING RELATION (2016, methodology): “The H-R diagram is shown in Figure 1, with each object represented by an open circle and the evolutionary tracks from Baraffe et al. (2015) and the nonmagnetic tracks from Feiden (2016) in solid (isochrones) and dashed (stellar mass tracks) lines.”
• Gaps and Rings in an ALMA Survey of Disks in the Taurus Star-forming Region (2018, methodology): “The stellar masses are then calculated from the Baraffe et al. (2015) and nonmagnetic Feiden (2016) evolutionary tracks, following Pascucci et al. (2016).”
• Evolved Climates and Observational Discriminants for the TRAPPIST-1 Planetary System (2018, background): “Although numerous, Mdwarf HZ planets likely face significant challenges to habitability, as their parent stars exhibit high stellar activity (Tarter et al. 2007) and intense, protracted stellar evolution (Baraffe et al. 2015).”
• THE HAWAII INFRARED PARALLAX PROGRAM. II. YOUNG ULTRACOOL FIELD DWARFS (2016, methodology): “We also examine BT-Settl evolutionary model isochrones (Baraffe et al. 2015; Allard et al. 2015, in preparation) that adopt a particular prescription for the formation and sedimentation of clouds as objects age (Allard et al. 2012).”