Age Determination in Upper Scorpius with Eclipsing Binaries
arXiv:1901.05532 · doi:10.3847/1538-4357/aafe09
Abstract
The Upper Scorpius OB association is the nearest region of recent massive star formation and thus an important benchmark for investigations concerning stellar evolution and planet formation timescales. We present nine EBs in Upper Scorpius, three of which are newly reported here and all of which were discovered from K2 photometry. Joint fitting of the eclipse photometry and radial velocities from newly acquired Keck-I/HIRES spectra yields precise masses and radii for those systems that are spectroscopically double-lined. The binary orbital periods in our sample range from 0.6-100 days, with total masses ranging from 0.2-8 . At least 33% of the EBs reside in hierarchical multiples, including two triples and one quadruple. We use these EBs to develop an empirical mass-radius relation for pre-main-sequence stars, and to evaluate the predictions of widely-used stellar evolutionary models. We report evidence for an age of 5-7 Myr which is self-consistent in the mass range of 0.3-5 and based on the fundamentally-determined masses and radii of eclipsing binaries (EBs). Evolutionary models including the effects of magnetic fields imply an age of 9-10 Myr. Our results are consistent with previous studies that indicate many models systematically underestimate the masses of low-mass stars by 20-60% based on H-R diagram analyses. We also consider the dynamical states of several binaries and compare with expectations from tidal dissipation theories. Finally, we identify RIK 72 b as a long-period transiting brown dwarf (, , days) and an ideal benchmark for brown dwarf cooling models at 5-10 Myr.
accepted to The Astrophysical Journal
References in corpus (37)
- Modules for Experiments in Stellar Astrophysics (MESA)
- The Dartmouth Stellar Evolution Database
- The K2 Mission: Characterization and Early results
- New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
- Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
- Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
- Improving PARSEC models for very low mass stars
- Tidal dissipation in stars and giant planets
- Tertiary companions to close spectroscopic binaries
- Spitzer Secondary Eclipses of the Dense, Modestly-irradiated, Giant Exoplanet HAT-P-20b Using Pixel-Level Decorrelation
- A spin-down clock for cool stars from observations of a 2.5-billion-year-old cluster
- EVEREST: Pixel Level Decorrelation of K2 Light curves
- Mapping the Shores of the Brown Dwarf Desert I.: Upper Scorpius
- Comparative statistics and origin of triple and quadruple stars
- Older and Colder: The impact of starspots on pre-main sequence stellar evolution
- A Surprising Reversal of Temperatures in the Brown-Dwarf Eclipsing Binary 2MASS J05352184-0546085
- Empirical Tests of Pre-Main-Sequence Stellar Evolution Models with Eclipsing Binaries
- New planetary and EB candidates from Campaigns 1-6 of the K2 mission
- New low-mass eclipsing binary systems in Praesepe discovered by K2
- New Pre-main-Sequence Stars in the Upper Scorpius Subgroup of Sco-Cen
- Self-Consistent Magnetic Stellar Evolution Models of the Detached, Solar-Type Eclipsing Binary EF Aquarii
- Zodiacal Exoplanets in Time (ZEIT) V: A Uniform Search for Transiting Planets in Young Clusters Observed by K2
- IN-SYNC I: Homogeneous Stellar Parameters from High Resolution APOGEE Spectra for Thousands of Pre-main Sequence Star
- A continuum of accretion burst behavior in young stars observed by K2
- EPIC 219388192 b - an inhabitant of the brown dwarf desert in the Ruprecht 147 open cluster
- Orbital Motion in Pre-Main Sequence Binaries
- The effect of starspots on the radii of low-mass pre-main sequence stars
- Using rotation rates to probe age spreads in the Orion Nebula Cluster
- M Dwarf rotation from the young clusters to the field. I. A Mass-Rotation Correlation at 10 Myr
- More Rapidly Rotating PMS M Dwarfs with Light Curves Suggestive of Orbiting Clouds of Material
- The Factory and the Beehive III: PTFEB132.707+19.810, a Low-Mass Eclipsing Binary in Praesepe Observed by PTF and K2
- Differential rotation on both components of the pre main-sequence binary system HD 155555
- Age spreads and the temperature dependence of age estimates in Upper Sco
- Near-Infrared Light Curves of the Brown Dwarf Eclipsing Binary 2MASS J05352184-0546085: Can Spots Explain the Temperature Reversal?
- A Transient Transit Signature Associated with the Young Star RIK-210
- Radial velocity measurements of B stars in the Scorpius-Centaurus association
- CoRoT 223992193: Investigating the variability in a low-mass, pre-main sequence eclipsing binary with evidence of a circumbinary disk