scholarly journals Analysis of eclipsing binaries in multiple stellar systems: the case of V1200 Centauri

2020 ◽  
Vol 499 (2) ◽  
pp. 3019-3033
Author(s):  
F Marcadon ◽  
K G Hełminiak ◽  
J P Marques ◽  
R Pawłaszek ◽  
P Sybilski ◽  
...  
Keyword(s):  
Eclipsing Binaries ◽  
Third Body ◽  
Low Mass Stars ◽  
Multiple Star ◽  
The Third ◽  
Tidal Interactions ◽  
Photometric Observations ◽  
Quadruple System ◽  
Low Mass ◽  
Stellar Properties

ABSTRACT We present a new analysis of the multiple-star V1200 Centauri based on the most recent observations for this system. We used the photometric observations from the Solaris network and the Transiting Exoplanet Survey Satellite telescope, combined with the new radial velocities from the CHIRON spectrograph and those published in the literature. We confirmed that V1200 Cen consists of a 2.5-d eclipsing binary orbited by a third body. We derived the parameters of the eclipsing components, which are $M_{\mathrm{ Aa}} = 1.393\pm 0.018\,$M⊙, $R_{\mathrm{ Aa}} = 1.407\pm 0.014\,$R⊙, and $T_{{\rm eff},\mathrm{ Aa}} = 6588\pm 58\,$K for the primary, and $M_{\mathrm{ Ab}} = 0.8633\pm 0.0081\,$M⊙, $R_{\mathrm{ Ab}} = 1.154\pm 0.014\,$R⊙, and $T_{{\rm eff},\mathrm{ Ab}} = 4475\pm 68\,$K for the secondary. Regarding the third body, we obtained significantly different results than those previously published. The period of the outer orbit is found to be 180.4 d, implying a minimum mass of $M_\mathrm{ B} = 0.871\pm 0.020\,$M⊙. Thus, we argue that V1200 Cen is a quadruple system with a secondary pair composed of two low-mass stars. Finally, we determined the ages of each eclipsing component using two evolution codes, namely mesa and cestam. We obtained ages of 16–18.5 and 5.5–7 Myr for the primary and the secondary, respectively. In particular, the secondary appears larger and hotter than that predicted at the age of the primary. We concluded that dynamical and tidal interactions occurring in multiples may alter the stellar properties and explain the apparent non-coevality of V1200 Centauri.

scholarly journals The New Era of Eclipsing Binary Research with Large Telescopes

2006 ◽  
Vol 2 (S240) ◽  
pp. 69-78
Author(s):  
Ignasi Ribas
Keyword(s):  
Eclipsing Binaries ◽  
Host Galaxies ◽  
Low Mass Stars ◽  
Eclipsing Binary ◽  
New Era ◽  
Direct Distance ◽  
Infrared Spectral ◽  
Low Mass ◽  
Stellar Properties ◽  
Large Telescopes

AbstractThe advent of larger telescopes and powerful instrumentation enables the exploration of new aspects of faint eclipsing binaries that are just now becoming accessible. An example of this are eclipsing binaries in Local Group galaxies such as the LMC, SMC, M31 and M33, whose study yields not only stellar properties of stars formed in different chemical environments (thus providing useful model tests) but also direct distance determinations to the host galaxies. In general this is also applicable to eclipsing binaries belonging to any stellar ensemble. Another example is the observation and study of eclipsing very-low mass stars, brown dwarfs and planets. Besides the need for large telescopes because of their faintness, these also benefit from improved observational capabilities in the infrared spectral windows. Here we discuss the prospects for eclipsing binary research using photometry and spectroscopy from large telescopes.

The impact of magnetism on tidal dynamics in the convective envelope of low-mass stars

2019 ◽  
Vol 15 (S354) ◽  
pp. 195-199
Author(s):  
A. Astoul ◽  
S. Mathis ◽  
C. Baruteau ◽  
F. Gallet ◽  
A. Strugarek ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Orbital Evolution ◽  
Magnetic Contribution ◽  
Low Mass Stars ◽  
Convective Envelope ◽  
Tidal Waves ◽  
Tidal Interactions ◽  
Rotational Evolution ◽  
Low Mass ◽  
The Impact

AbstractFor the shortest period exoplanets, star-planet tidal interactions are likely to have played a major role in the ultimate orbital evolution of the planets and on the spin evolution of the host stars. Although low-mass stars are magnetically active objects, the question of how the star’s magnetic field impacts the excitation, propagation and dissipation of tidal waves remains open. We have derived the magnetic contribution to the tidal interaction and estimated its amplitude throughout the structural and rotational evolution of low-mass stars (from K to F-type). We find that the star’s magnetic field has little influence on the excitation of tidal waves in nearly circular and coplanar Hot-Jupiter systems, but that it has a major impact on the way waves are dissipated.

scholarly journals Dependence of star formation on initial conditions and molecular cloud structure

2010 ◽  
Vol 6 (S270) ◽  
pp. 133-140
Author(s):  
Matthew R. Bate
Keyword(s):  
Star Formation ◽  
Molecular Cloud ◽  
Initial Conditions ◽  
Small Scale ◽  
Low Mass Stars ◽  
Cloud Structure ◽  
Low Mass ◽  
Stellar Properties ◽  
Stellar Masses ◽  
Formation Of Groups

AbstractI review what has been learnt so far regarding the origin of stellar properties from numerical simulations of the formation of groups and clusters of stars. In agreement with observations, stellar properties are found to be relatively robust to variations of initial conditions in terms of molecular cloud structure and kinetics, as long as extreme initial conditions (e.g. strong central condensation, weak or no turbulence) and small-scale driving are avoided, but properties may differ between bound and unbound clouds. Radiative feedback appears crucial for setting stellar masses, even for low-mass stars, while magnetic fields can provide low star formation rates.

scholarly journals Systematic search for stellar pulsators in the eclipsing binaries observed by Kepler

2019 ◽  
Vol 630 ◽  
pp. A106 ◽  
Author(s):  
Patrick Gaulme ◽  
Joyce A. Guzik
Keyword(s):  
Stellar Evolution ◽  
Percent Level ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Systematic Search ◽  
Red Giants ◽  
Low Mass Stars ◽  
Orbital Periods ◽  
Red Giant ◽  
Stellar Properties

Eclipsing binaries (EBs) are unique targets for measuring precise stellar properties and can be used to constrain stellar evolution models. In particular, it is possible to measure masses and radii of both components of a double-lined spectroscopic EB at the percent level. Since the advent of high-precision photometric space missions (MOST, CoRoT, Kepler, BRITE, TESS), the use of stellar pulsation properties to infer stellar interiors and dynamics constitutes a revolution for studies of low-mass stars. The Kepler mission has led to the discovery of thousands of classical pulsators such as δ Scuti and solar-like oscillators (main sequence and evolved), but also almost 3000 EBs with orbital periods shorter than 1100 days. We report the first systematic search for stellar pulsators in the entire Kepler EB catalog. The focus is mainly aimed at discovering δ Scuti, γ Doradus, red giant, and tidally excited pulsators. We developed a data inspection tool (DIT) that automatically produces a series of plots from the Kepler light curves that allows us to visually identify whether stellar oscillations are present in a given time series. We applied the DIT to the whole Kepler EB database and identified 303 systems whose light curves display oscillations, including 163 new discoveries. A total of 149 stars are flagged as δ Scuti (100 from this paper), 115 as γ Doradus (69 new), 85 as red giants (27 new), and 59 as tidally excited oscillators (29 new). There is some overlap among these groups, as some display several types of oscillations. Despite the likelihood that many of these systems are false positives, for example, when an EB light curve is blended with a pulsator, this catalog gathers a vast sample of systems that are valuable for a better understanding of stellar evolution.

scholarly journals A Relative Age Test of Pre-Main Sequence Evolutionary Models Based on the Young Quadruple System GG Tauri

2001 ◽  
Vol 200 ◽  
pp. 464-467
Author(s):  
Russel J. White
Keyword(s):  
Spectral Type ◽  
Temperature Scale ◽  
Main Sequence ◽  
Evolutionary Models ◽  
Low Mass Stars ◽  
Relative Age ◽  
Wide Range ◽  
Quadruple System ◽  
Low Mass

The components of the young hierarchical quadruple GG Tau, which span a wide range in spectral type (K7 – M7.5), are used to test both evolutionary models and the temperature scale for very young, low mass stars under the assumption of coeval formation. Of the evolutionary models tested which extend into the substellar regime, those of Baraffe et al. yield the most consistent ages when combined with a temperature scale intermediate between that of dwarfs and giants. The Palla & Stahler and Siess et al. models are also capable of yielding a coeval age down to their lowest mass (0.1 M⊙). These latter two models, which extend to much higher masses than the Baraffe et al. models, agree reasonably well with the Baraffe et al. models at 1.0 M⊙ and thus could be combined to construct a set evolutionary models that extends from Substellar to several solar masses.

scholarly journals High-resolution spectroscopy of detached solar-type eclipsing binaries observed during the Kepler K2 mission

2020 ◽  
Vol 493 (2) ◽  
pp. 2329-2338
Author(s):  
B Hoyman ◽  
Ö Çakırlı
Keyword(s):  
Theoretical Models ◽  
Eclipsing Binaries ◽  
High Resolution Spectroscopy ◽  
Physical Parameters ◽  
Evolutionary Status ◽  
Low Mass Stars ◽  
Ongoing Effort ◽  
Stellar Parameter ◽  
Solar Type ◽  
Low Mass

ABSTRACT Solar-type stars in eclipsing binaries are proving to be a remarkable resource of knowledge for testing models of stellar evolution, as spectroscopic and photometric studies have opened up a window into their interiors. Until recently, many cases have been worked out with Kepler data. In an ongoing effort to elucidate this research, we examine five detached eclipsing binaries, selected from the Kepler catalogue. There is a well-known stellar parameter discrepancy for low-mass stars, in that the observed radii and masses are often larger and stars overluminous than predicted by theory by several per cent. In our samples, we found five double-lined binaries, with solar-type stars dominating the spectrum. The orbital and light-curve solutions were found for them, and compared with isochrones, in order to estimate absolute physical parameters and evolutionary status of the components. An important aspect of this work is that the calculated stellar radii and masses are consistent with theoretical models within the uncertainties, whereas the estimated temperatures from the disentangled spectra of the components are no different than predicted.

scholarly journals Deep inside low-mass stars

2008 ◽  
Vol 4 (S252) ◽  
pp. 163-174 ◽  
Author(s):  
Corinne Charbonnel ◽  
Suzanne Talon
Keyword(s):  
Large Scale ◽  
Main Sequence ◽  
Internal Gravity Waves ◽  
Transport Processes ◽  
Atomic Diffusion ◽  
Physical Processes ◽  
Low Mass Stars ◽  
Low Mass ◽  
Stellar Properties ◽  
The Impact

AbstractLow-mass stars exhibit, at all stages of their evolution, the signatures of complex physical processes that require challenging modeling beyond standard stellar theory. In this review, we recall the most striking observational evidences that probe the interaction and interdependence of various transport processes of chemicals and angular momentum in these objects. We then focus on the impact of atomic diffusion, large scale mixing due to rotation, and internal gravity waves on stellar properties on the main sequence and slightly beyond.

scholarly journals CM Draconis: Masses and Radii of Very Low Mass Stars

2006 ◽  
Vol 2 (S240) ◽  
pp. 628-630
Author(s):  
J.C. Morales ◽  
I. Ribas ◽  
C. Jordi ◽  
G. Torres ◽  
E.F. Guinan ◽  
...  
Keyword(s):  
Magnetic Activity ◽  
Time Span ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Low Mass Stars ◽  
Fundamental Properties ◽  
Low Mass ◽  
Effective Temperatures ◽  
Better Than

AbstractIn this work we have studied CM Draconis, one of the least massive eclipsing binaries known. Its components are very similar, with masses and radii of about 0.23 M⊙ and 0.25 R⊙. We have analysed light curves in the R and I bands to calculate the fundamental properties of this system with accuracies better than 1%. With these results we plan to carry out a thorough test of the models, which have been found to predict smaller radii and larger effective temperatures than observed for these low-mass stars. This will also be especially interesting in the case of CM Dra since the mechanism driving magnetic activity is thought to be different from that of more massive stars. In addition, the extended time-span of the observations has led to the detection of apsidal motion. This provides a further check on models through the determination of the internal structure of the stars.

scholarly journals Do Magnetic Fields Actually Inflate Low-Mass Stars?

2013 ◽  
Vol 9 (S302) ◽  
pp. 150-153
Author(s):  
Gregory A. Feiden ◽  
Brian Chaboyer
Keyword(s):  
Magnetic Fields ◽  
Eclipsing Binaries ◽  
Scaling Relation ◽  
Model Surface ◽  
Outer Envelope ◽  
Low Mass Stars ◽  
Convective Boundary ◽  
X Ray ◽  
Surface Magnetic Field ◽  
Low Mass

AbstractMagnetic fields have been hypothesized to inflate the radii of low-mass stars—defined as less than 0.8 M⊙–in detached eclipsing binaries (DEBs). We evaluate this hypothesis using the magnetic Dartmouth stellar evolution code. Results suggest that magnetic suppression of thermal convection can inflate low-mass stars that possess a radiative core and convective outer envelope. A scaling relation between X-ray luminosity and surface magnetic flux indicates that model surface magnetic field strength predictions are consistent with observations. This supports the notion that magnetic fields may be inflating these stars. However, magnetic models are unable to reproduce radii of fully convective stars in DEBs. Instead, we propose that model discrepancies below the fully convective boundary are related to metallicity.

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