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There are two methods often used to observe and measure the separation of known binary stars. One uses an astrometric eyepiece and the other uses CCD images. With measurements taken at the Colorado Mountain College Ball Observatory, the relative accuracy and precision of these two methods was compared using observations of the known binary WDS 19121+4951. The use of CCD Images was more accurate and precise than the use of an astrometric eyepiece. The average position angle and separation measured using the astrometric eyepiece were 200.6⁰ and 8.0" with a standard deviation of 2.29 and 0.51 respectively, and are considerably far from the published orbital predictions, whereas the average position angle and separation measured using CCD Images were 202.89⁰ and 7.02" with a standard deviation of 0.11 and 0.016 which is much closer to the published orbital predictions. 

Abstract Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals. 

Advanced LIGO and Advanced Virgo are monitoring the sky and collecting gravitational-wave strain data with sufficient sensitivity to detect signals routinely. In this paper we describe the data recorded by these instruments during their first and second observing runs. The main data products are gravitational-wave strain time series sampled at 16384 Hz. The datasets that include this strain measurement can be freely accessed through the Gravitational Wave Open Science Center at http://gw-openscience.org, together with data-quality information essential for the analysis of LIGO and Virgo data, documentation, tutorials, and supporting software.