Pre-main sequence spectroscopic binaries suitable for VLTI observations

Abstract

A severe problem of the research in star-formation is that the masses of young stars are almost always estimated only from evolutionary tracks. Since the tracks published by different groups differ, it is often only possible to give a rough estimate of the masses of young stars. It is thus crucial to test and calibrate the tracks. Up to now, only a few tests of the tracks could be carried out. However, with the VLTI it is now possible to set constrains on the tracks by determining the masses of many young binary stars precisely. In order to use the VLTI efficiently, a first step is to find suitable targets, which is the purpose of this work. Given the distance of nearby star-forming regions, suitable VLTI targets are binaries with orbital periods between at least 50 days, and few years. Although a number of surveys for detecting spectroscopic binaries have been carried out, most of the binaries found so far have periods which are too short. We thus surveyed the Chamaeleon, Corona Australis, Lupus, Sco-Cen, rho Ophiuci star-forming regions in order to search for spectroscopic binaries with periods longer than 50 days, which are suitable for the VLTI observations. As a result of the 8 years campaign we discovered 8 binaries with orbital periods longer than 50 days. Amongst the newly discovered long period binaries is CS Cha, which is one of the few classical T Tauri stars with a circumbinary disk. The survey is limited to objects with masses higher than 0.1 to 0.2 Modot for periods between 1 and 8 years. We find that the frequency of binaries with orbital periods < 3000 days is of 20+/-5 percent. The frequency of long and short period pre-main sequence spectroscopic binaries is about the same as for stars in the solar neighbourhood. In total 14 young binaries are now known which are suitable for mass determination with the VLTI.

16 pages

References in corpus (27)

• A Non-Gray Theory of Extrasolar Giant Planets and Brown Dwarfs
• A Hipparcos census of the nearby OB associations
• Theory of Low-Mass Stars and Substellar Objects
• Dynamical Masses of T Tauri Stars and Calibration of PMS Evolution
• Discovery of seven T Tauri stars and a brown dwarf candidate in the nearby TW Hydrae Association
• Evidence for a Long-period Planet Orbiting Epsilon Eridani
• A New Association of Post-T Tauri Stars Near The Sun
• Formation scenarios for the young stellar associations between galactic longitudes l = 280-360 deg
• Confirmation of the Planet Hypothesis for the Long-period Radial Velocity Variations of Beta Geminorum
• Formation and Evolution of Planetary Systems (FEPS): Primordial Warm Dust Evolution From 3-30 Myr around Sun-like Stars
• A spectro-astrometric study of southern pre-main sequence stars - binaries, outflows, and disc structure down to AU scales
• Dynamical Mass Constraints on Low-Mass Pre-Main-Sequence Stellar Evolutionary Tracks: An Eclipsing Binary in Orion with a 1.0 Msun Primary and an 0.7 Msun Secondary
• Radial-velocity survey of members and candidate members of the TW Hydrae association
• The Smallest Mass Ratio Young Star Spectroscopic Binaries
• Dynamical Masses for Low-Mass Pre-Main Sequence Stars: A Preliminary Physical Orbit for HD 98800 B
• Searching for Planets in the Hyades II: Some Implications of Stellar Magnetic Activity
• The Ages of Pre-main-sequence Stars
• A Dynamical Mass Constraint for Pre-Main-Sequence Evolutionary Tracks: The Binary NTT 045251+3016
• The HARPS search for southern extra-solar planets. III. Three Saturn-mass planets around HD 93083, HD 101930 and HD 102117
• Convection in the atmospheres and envelopes of Pre-Main Sequence stars
• A Search for Warm Circumstellar Disks in the TW Hydrae Association
• Periodic radial velocity variations in RU Lupi
• Multiplicity of X-Ray Selected T Tauri Stars in Chamaeleon
• Additional TWA Members? : Spectroscopic verification of kinematically selected TWA candidates
• The young, active binary star EK Draconis
• The Double-Lined Spectroscopic Binary Haro 1-14c
• The T Tauri star RXJ1608.6-3922 - not an eclipsing binary but a spotted single star

Cited by in corpus (88)

• Protoplanetary Disk Structures in Ophiuchus
• BANYAN. XI. The BANYAN $\Sigma$ multivariate Bayesian algorithm to identify members of young associations within 150 pc
• The Disk Population of the Taurus Star-Forming Region
• X-Shooter spectroscopy of young stellar objects: IV -- Accretion in low-mass stars and sub-stellar objects in Lupus
• Bayesian analysis to identify new star candidates in nearby young stellar kinematic groups
• Line-profile tomography of exoplanet transits -- II. A gas-giant planet transiting a rapidly-rotating A5 star
• Accretion Rates for T Tauri Stars Using Nearly Simultaneous Ultraviolet and Optical Spectra
• A Spitzer survey of mid-infrared molecular emission from protoplanetary disks I: Detection rates
• The Palomar/Keck Adaptive Optics Survey of Young Solar Analogs: Evidence for a Universal Companion Mass Function
• The Disk Around CoKu Tau/4: Circumbinary, not Transitional
• Mapping the Shores of the Brown Dwarf Desert I.: Upper Scorpius
• A Spitzer IRS Study of Infrared Variability in Transitional and Pre-Transitional Disks around T Tauri Stars
• Circumbinary, not transitional: On the spiral arms, cavity, shadows, fast radial flows, streamers and horseshoe in the HD142527 disc
• Close Companions to Young Stars. I. A Large Spectroscopic Survey in Chamaeleon I and Taurus-Auriga
• On the gas content of transitional disks: a VLT/X-Shooter study of accretion and winds
• Disk Evolution in the three Nearby Star-Forming Regions of Taurus, Chamaeleon, and Ophiuchus
• Evidence for Disk Photoevaporation Driven by the Central Star
• RACE-OC Project: Rotation and variability in young stellar associations within 100 pc
• VLT-CRIRES Survey of Rovibrational CO Emission from Protoplanetary Disks
• Measuring Protoplanetary Disk Accretion with H I Pf-beta
• On the Distance to the Ophiuchus Star-Forming Region
• The Degree of Alignment Between Circumbinary Disks and Their Binary Hosts
• A Hubble Space Telescope Survey of H2 Emission in the Circumstellar Environments of Young Stars
• The many-faceted light curves of young disk-bearing stars in Upper Sco and $\rho$ Oph observed by $K2$ Campaign 2
• Surface magnetic fields on two accreting T Tauri stars: CV Cha and CR Cha
• The Spitzer c2d Survey of Weak-Line T Tauri Stars. III. The Transition from Primordial Disks to Debris Disks
• Direct evidence of a sub-stellar companion around CT Cha
• Single peaked CO emission line profiles from the inner regions of protoplanetary disks
• Hot Gas Lines in T Tauri Stars
• Re-examining the membership and origin of the Epsilon Cha association
• Silica in Protoplanetary Disks
• LACEwING: A New Moving Group Analysis Code
• The (w)hole survey: an unbiased sample study of transition disk candidates based on Spitzer catalogs
• RACE-OC Project: Rotation and variability in the epsilon Chamaeleontis, Octans, and Argus stellar associations
• High resolution spectroscopy of Ne II emission from young stellar objects
• Search for Associations Containing Young stars (SACY): Chemical tagging IC 2391 & the Argus association
• Spitzer Infrared Spectrograph survey of young stars in the Chamaeleon I star-forming region
• The Evolution of Disk Winds from a Combined Study of Optical and Infrared Forbidden Lines
• A continuum of accretion burst behavior in young stars observed by K2
• Large grains in disks around young stars: ATCA observations of WW Cha, RU Lup, and CS Cha
• EX Lupi in quiescence
• Measurements of water surface snow lines in classical protoplanetary disks
• Variability of the transitional T Tauri star T Chamaeleontis
• Low EUV Luminosities Impinging on Protoplanetary Disks
• Lupus DANCe. Census of stars and 6D structure with Gaia-DR2 data
• ACRONYM III: Radial Velocities for 336 Candidate Young Low-Mass Stars in the Solar Neighborhood, Including 78 Newly Confirmed Young Moving Group Members
• Dynamical Masses of Young Stars I: Discordant Model Ages of Upper Scorpius
• SPOTS: The Search for Planets Orbiting Two Stars: II. First constraints on the frequency of sub-stellar companions on wide circumbinary orbits
• A kinematic study and membership analysis of the Lupus star-forming region
• Chamaeleon DANCe. Revisiting the stellar populations of Chamaeleon I and Chamaeleon II with Gaia-DR2 data
• Mid-Infrared Spectral Variability Atlas of Young Stellar Objects
• A slowly accreting ~10 Myr old transitional disk in Orion OB1a
• First direct detection of a polarized companion outside of a resolved circumbinary disk around CS Cha
• The Gaia-ESO Survey: Structural and dynamical properties of the young cluster Chamaeleon I
• IN-SYNC VI. Identification and Radial Velocity Extraction for 100+ Double-Lined Spectroscopic Binaries in the APOGEE/IN-SYNC Fields
• Herschel evidence for disk flattening or gas depletion in transitional disks
• The Giant Accreting Protoplanet Survey (GAPlanetS) -- Results from a Six Year Campaign to Image Accreting Protoplanets
• SPOTS: The Search for Planets Orbiting Two Stars. III. Complete Sample and Statistical Analysis
• The Frequency Of Binary Star Interlopers Amongst Transitional Discs
• GW Ori: Inner disk readjustments in a triple system
• CO Fundamental Emission from V836 Tau
• Tracing High-Energy Radiation from T Tauri Stars Using Mid-Infrared Neon Emission from Disks
• Spots, flares, accretion, and obscuration in the pre-main sequence binary DQ Tau
• The quadruple pre-main sequence system LkCa3: Implications for stellar evolution models
• Radial velocity variations in the young eruptive star EX Lup
• Spatially Resolved Mid-IR Imaging of the SR 21 Transition Disk
• Chronostar. II. Kinematic age and substructure of the Scorpius-Centaurus OB2 association
• Astrometric confirmation of young low-mass binaries and multiple systems in the Chamaeleon star-forming regions
• Proper motion survey and kinematic analysis of the Rho Ophiuchi embedded cluster
• Signatures of warm carbon monoxide in protoplanetary discs observed with Herschel SPIRE
• Gaia-based Isochronal, Kinematic, and Spatial Analysis of the $\epsilon$ Cha Association
• New companions in the stellar systems of DI Cha, Sz 22, CHXR 32, and Cha Halpha 5 in the Cha I star-forming region
• Stellar multiplicity affects the correlation between proto-planetary disc masses and accretion rates: binaries explain high-accretors in Upper Sco
• Identification of transitional disks in Chamaeleon with Herschel
• Molecules in the transition disk orbiting T Cha
• Deep XMM-Newton observation of the Eta Chamaleontis cluster
• Constraints to the magnetospheric properties of T Tauri stars. I. The C II], Fe II] and Si II] ultraviolet features
• CS Cha B: A disc-obscured M-type star mimicking a polarised planetary companion
• Constraining the properties of transitional disks in Chamaeleon I with Herschel
• Mid-infrared variability of the binary system CS Cha
• Detection of Strong Millimeter Emission from the Circumstellar Dust Disk Around V1094 Sco: Cold and Massive Disk around a T Tauri Star in a Quiescent Accretion Phase?
• A kinematically unbiased, all-sky search for nearby, young, low-mass stars
• Young and eccentric: the quadruple system HD 86588
• Accretion and inter-cycle variations in the PMS interacting binary AK Sco
• Fundamental stellar parameters for selected T-Tauri stars in the Chamaeleon and Rho Ophiuchus star-forming regions
• The evolution of velocity dispersion in the Sco-Cen OB association
• Finding new sub-stellar co-moving companion candidates - the case of CT Cha
• The morphology of CSCha circumbinary disk suggesting the existence of a Saturn-mass planet