Age Determination in Upper Scorpius with Eclipsing Binaries

David, Trevor J.; Hillenbrand, Lynne A.; Gillen, Edward; Cody, Ann Marie; Howell, Steve B.; Isaacson, Howard; Livingston, John H.

doi:10.3847/1538-4357/aafe09

Cited by 109 publications

(123 citation statements)

References 161 publications

(225 reference statements)

Supporting

Mentioning

115

Contrasting

Order By: Relevance

“…Following these criteria, we separate the populations into the following age bins: Table 1 shows properties of all stellar populations in §2.1 and the age bin we assigned to them. We assigned Upper Scorpius to the third age bin, in agreement with its disk fraction and with the age (5-7 Myr) recently determined by David et al (2019), although some authors suggest it is older (∼ 11 Myr, Pecaut et al 2012;Song et al 2012). To test the goodness of our assemblage of age bins, we plot the median of the stellar luminosity estimated in §2.2 vs the age of each bin ( Figure 4).…”

Section: Separation Into Age Binssupporting

confidence: 88%

“…Based on the GAIA first data release, Galli et al (2018) estimate a mean distance of ∼146 pc. Stellar ages estimated for Upper Scorpius range from ∼5 (Preibisch et al 2002) to 11 Myr (Pecaut et al 2012) and recently, using eclipsing binaries, David et al (2019) estimate and age of 5-7 Myr. Out of 306 stars in Luhman & Mamajek (2012) with spectral types ranging from K0 to M6, 74 stars have protoplanetary disks.…”

Section: Upper Scomentioning

confidence: 98%

See 1 more Smart Citation

The Evolution of the Inner Regions of Protoplanetary Disks

Manzo-Martínez

Calvet

Hernández

et al. 2020

ApJ

View full text Add to dashboard Cite

We present a study of the evolution of the inner few au of protoplanetary disks around low-mass stars. We consider nearby stellar groups with ages spanning from 1 to 11 Myr, distributed into four age bins. Combining PANSTARSS photometry with spectral types we derive the reddening consistently for each star, which we use (1) to measure the excess emission above the photosphere with a new indicator of IR excess and (2) to estimate the mass accretion rate (Ṁ ) from the equivalent width of the Hα line. Using the observed decay ofṀ as a constrain to fix the initial conditions and the viscosity parameter of viscous evolutionary models, we use approximate Bayesian modeling to infer the dust properties that produce the observed decrease of the IR excess with age, in the range between 4.5 µm and 24 µm. We calculate an extensive grid of irradiated disk models with a two-layered wall to emulate a curved dust inner edge and obtain the vertical structure consistent with the surface density predicted by viscous evolution. We find that the median dust depletion in the disk upper layers is ǫ ∼ 3 × 10 −3 at 1.5 Myr, consistent with previous studies, and it decreases to ǫ ∼ 3 × 10 −4 by 7.5 Myr. We include photoevaporation in a simple model of the disk evolution and find that a photoevaporative wind mass-loss rate of ∼ 1 − 3 × 10 −9 M ⊙ yr −1 agrees with the decrease of the disk fraction with age reasonably well. The models show the inward evolution of the H 2 O and CO snowlines.

show abstract

Section: Separation Into Age Binssupporting

confidence: 88%

Section: Upper Scomentioning

confidence: 98%

The Evolution of the Inner Regions of Protoplanetary Disks

Manzo-Martínez

Calvet

Hernández

et al. 2020

ApJ

View full text Add to dashboard Cite

show abstract

“…Finally, we note that even if the out-of-eclipse variation is not caused by spot modulation (or is removed prior to fitting; e.g. David et al 2019), the radii derived from the light curve fit should not be significantly affected.…”

Section: Parameter Estimationmentioning

confidence: 98%

THOR 42: A touchstone ∼24 Myr-old eclipsing binary spanning the fully-convective boundary

Murphy

Lawson

Onken

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present the characterization of CRTS J055255.7−004426 (=THOR 42), a young eclipsing binary comprising two pre-main sequence M dwarfs (combined spectral type M3.5). This nearby (103 pc), short-period (0.859 d) system was recently proposed as a member of the ∼24 Myr-old 32 Orionis Moving Group. Using ground-and space-based photometry in combination with medium-and high-resolution spectroscopy, we model the light and radial velocity curves to derive precise system parameters. The resulting component masses and radii are 0.497 ± 0.005 and 0.205 ± 0.002 M , and 0.659 ± 0.003 and 0.424 ± 0.002 R , respectively. With mass and radius uncertainties of ∼1 per cent and ∼0.5 per cent, respectively, THOR 42 is one of the most precisely characterized pre-main sequence eclipsing binaries known. Its systemic velocity, parallax, proper motion, colour-magnitude diagram placement and enlarged radii are all consistent with membership in the 32 Ori Group. The system provides a unique opportunity to test pre-main sequence evolutionary models at an age and mass range not well constrained by observation. From the radius and mass measurements we derive ages of 22-26 Myr using standard (non-magnetic) models, in excellent agreement with the age of the group. However, none of the models can simultaneously reproduce the observed mass, radius, temperature and luminosity of the coeval components. In particular, their H-R diagram ages are 2-4 times younger and we infer masses ∼50 per cent smaller than the dynamical values.

show abstract

“…Dark dots depict mass/radius measurements for interferometric measurements, single line eclipsing binaries and transiting exoplanets. The young brown dwarfs 2M0535AB [11] and RIK 27b [7] are explicitly labelled. 2M1510A's parameters are consistent with the 45±5 Myr age of the Argus moving group, just below a 40 Myr isochrone highlighted in black.…”

Section: Code Availabilitymentioning

confidence: 99%

“…Note that directly imaged planetary mass objects do not have measured radii. 2M1510Aa & Ab are represented as a single black point, and along with 2M0535AB [11] and RIK 72b [7] are the smallest and least massive objects with measured masses, radii and age (panel a). Together they form an empirical isochrone for masses close to 40 Mjup.…”

Section: Mass [Msol]mentioning

confidence: 99%

An eclipsing substellar binary in a young triple system discovered by SPECULOOS

et al. 2020

View full text Add to dashboard Cite

corresponding authors Mass, radius, and age are three of the most fundamental parameters for celestial objects, enabling studies of the evolution and internal physics of stars, brown dwarfs, and planets. Brown dwarfs are hydrogen-rich objects that are unable to sustain core fusion reactions but are supported from collapse by electron degeneracy pressure [1]. As they age, brown dwarfs cool, reducing their radius and luminosity. Young exoplanets follow a similar behaviour. Brown dwarf evolutionary models are relied upon to infer the masses, radii and ages of these objects [2, 3]. Similar models are used to infer the mass and radius of directly imaged exoplanets [4]. Unfortunately, only sparse empirical mass, radius and age measurements are currently available, and the models remain mostly unvalidated. Double-line eclipsing binaries provide the most direct route for the absolute determination of the masses and radii of stars [5, 6, 7]. Here, we report the SPECULOOS discovery of 2M1510A, a nearby, eclipsing, double-line brown dwarf binary, with a widely-separated tertiary brown dwarf companion. We also find that the system is a member of the 45±5 Myr-old moving group, Argus [8, 9]. The system's age matches those of currently known directly-imaged exoplanets. 2M1510A provides an opportunity to benchmark evolutionary models of brown dwarfs and young planets. We find that widely-used evolutionary models [4] do reproduce the mass, radius and age of the binary components remarkably well, but overestimate the luminosity by up to 0.65 magnitudes, which could result in underestimated photometric masses for directly-imaged exoplanets and young field brown dwarfs by 20 to 35%.

show abstract

Age Determination in Upper Scorpius with Eclipsing Binaries

Cited by 109 publications

References 161 publications

The Evolution of the Inner Regions of Protoplanetary Disks

The Evolution of the Inner Regions of Protoplanetary Disks

THOR 42: A touchstone ∼24 Myr-old eclipsing binary spanning the fully-convective boundary

An eclipsing substellar binary in a young triple system discovered by SPECULOOS

Contact Info

Product

Resources

About