Orbital Parameter Determination for Wide Stellar Binary Systems in the Age of Gaia

The orbits of binary stars and planets, particularly eccentricities and inclinations, encode the angular momentum within these systems. Within stellar multiple systems, the magnitude and (mis)alignment of angular momentum vectors among stars, disks, and planets probes the complex dynamical processes guiding their formation and evolution. The accuracy of the Gaia catalog can be exploited to enable comparison of binary orbits with known planet or disk inclinations without costly long-term astrometric campaigns. We show that Gaia astrometry can place meaningful limits on orbital elements in cases with reliable astrometry, and discuss metrics for assessing the reliability of Gaia DR2 solutions for orbit fitting. We demonstrate our method by determining orbital elements for three systems (DS Tuc AB, GK/GI Tau, and Kepler-25/KOI-1803) using Gaia astrometry alone. We show that DS Tuc AB's orbit is nearly aligned with the orbit of DS Tuc Ab, GK/GI Tau's orbit might be misaligned with their respective protoplanetary disks, and the Kepler-25/KOI-1803 orbit is not aligned with either component's transiting planetary system. We also demonstrate cases where Gaia astrometry alone fails to provide useful constraints on orbital elements. To enable broader application of this technique, we introduce the python tool lofti_gaiaDR2 to allow users to easily determine orbital element posteriors

Toward Male Individualization with Rapidly Mutating Y-Chromosomal Short Tandem Repeats

Peer reviewe

Further evidence of an Amerindian contribution to the Polynesian gene pool on Easter Island

Available evidence suggests a Polynesian origin of the Easter Island population. We recently found that some native Easter Islanders also carried some common American Indian (Amerindian) human leukocyte antigen (HLA) alleles, which probably were introduced before Europeans discovered the island in 1722. In this study, we report molecular genetic investigations of 21 other selected native Easter Islanders. Analysis of mitochondrial DNA and Y chromosome markers showed no traces of an Amerindian contribution. However, high-resolution genomic HLA typing showed that two individuals carried some other common Amerindian HLA alleles, different from those found in our previous investigations. The new data support our previous evidence of an Amerindian contribution to the gene pool on Easter Island

Large-scale recent expansion of European patrilineages shown by population resequencing

Molecular Technology and Informatics for Personalised Medicine and Healt

The Y-Chromosome Tree Bursts into Leaf: 13,000 High-Confidence SNPs Covering the Majority of Known Clades

Molecular Technology and Informatics for Personalised Medicine and Healt