English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We report the discovery of three low-mass double-lined eclipsing binaries inthe pre-main sequence Upper Scorpius association, revealed by $K2$ photometricmonitoring of the region over $\sim$ 78 days. The orbital periods of all threesystems are $<$5 days. We use the $K2$ photometry plus multiple Keck/HIRESradial velocities and spectroscopic flux ratios to determine fundamentalstellar parameters for both the primary and secondary components of eachsystem, along with the orbital parameters. We present tentative evidence thatEPIC 203868608 is a hierarchical triple system comprised of an eclipsing pairof $\sim$25 $M_\mathrm{Jup}$ brown dwarfs with a wide M-type companion. Ifconfirmed, it would constitute only the second double-lined eclipsing browndwarf binary system discovered to date. The double-lined system EPIC 203710387is composed of nearly identical M4.5-M5 stars with fundamentally determinedmasses and radii measured to better than 3% precision ($M_1=0.1183\pm0.0028M_\odot$, $M_2=0.1076\pm0.0031 M_\odot$ and $R_1=0.417\pm0.010 R_\odot$,$R_2=0.450\pm0.012 R_\odot$) from combination of the light curve and radialvelocity time series. These stars have the lowest masses of any stellar massdouble-lined eclipsing binary to date. Finally, EPIC 203476597 is a compactsingle-lined system with a G8-KO primary and a likely mid-K secondary whoseline are revealed in spectral ratios. Continued measurement of radialvelocities and spectroscopic flux ratios will better constrain fundamentalparameters and should elevate the objects to benchmark status. We also presentrevised parameters for the double-lined eclipsing binary UScoCTIO 5($M_1=0.3336\pm0.0022 M_\odot$, $M_2=0.3200\pm0.0022 M_\odot$ and$R_1=0.862\pm0.012$, $R_2=0.852\pm0.013 R_\odot$). We discuss the implicationsof our results on these $\sim$0.1-1.5 $M_\odot$ stars for pre-main-sequenceevolutionary models.

astrophysical journal/the astrophysical journal

K2 Discovery of Young Eclipsing Binaries in Upper Scorpius: Direct Mass  and Radius Determinations for the Lowest Mass Stars and Initial  Characterization of an Eclipsing Brown Dwarf Binary