30,994 research outputs found
The Interior Structure Constants as an Age Diagnostic for Low-Mass, Pre-Main Sequence Detached Eclipsing Binary Stars
We propose a novel method for determining the ages of low-mass, pre-main
sequence stellar systems using the apsidal motion of low-mass detached
eclipsing binaries. The apsidal motion of a binary system with an eccentric
orbit provides information regarding the interior structure constants of the
individual stars. These constants are related to the normalized stellar
interior density distribution and can be extracted from the predictions of
stellar evolution models. We demonstrate that low-mass, pre-main sequence stars
undergoing radiative core contraction display rapidly changing interior
structure constants (greater than 5% per 10 Myr) that, when combined with
observational determinations of the interior structure constants (with 5 -- 10%
precision), allow for a robust age estimate. This age estimate, unlike those
based on surface quantities, is largely insensitive to the surface layer where
effects of magnetic activity are likely to be most pronounced. On the main
sequence, where age sensitivity is minimal, the interior structure constants
provide a valuable test of the physics used in stellar structure models of
low-mass stars. There are currently no known systems where this technique is
applicable. Nevertheless, the emphasis on time domain astronomy with current
missions, such as Kepler, and future missions, such as LSST, has the potential
to discover systems where the proposed method will be observationally feasible.Comment: Accepted for publication in ApJ, 8 pages, 3 figure
Compelling Intimacies: Domesticity, Sexuality, and Agency
This introduction highlights what we call Compelling Intimacies —the multiple desires, affects, and affinities that arise at the intersection of institutions, actors, technologies, and ethical discourses to exert persuasive pressures on subjects. Each article animates different facets of the intensities born of intimacy as they operate across social and relational fields. The authors separate agency from intention in their efforts to identify the vitality of human and non-human relations. Together, the articles demonstrate how domesticities arise through diverse sets of circumstances, emerging in multiple incarnations—often in the same household—in such a way as to generate a wide range of affects and affinities. Finally, each author turns attention to the so-called small events that come to affirm or deny life as given form in everyday household arrangements, kin relations, friendships, and institutional settings, thereby suggesting the political stakes evoked by differing forms of care
- …