2 research outputs found
On the behaviour of spin-orbit connection of exoplanets
Star-planet interactions play, among other things, a crucial role in
planetary orbital configurations by circularizing orbits, aligning the star and
planet spin and synchronizing stellar rotation with orbital motions. This is
especially true for innermost giant planets, which can be schematized as binary
systems with a very large mass ratio. Despite a few examples where spin-orbit
synchronization has been obtained, there is no demographic study on synchronous
regimes in those systems yet. Here we use a sample of 1,055 stars with
innermost planet companions to show the existence of three observational loci
of star-planet synchronization regimes. Two of them have dominant fractions of
subsynchronous and supersynchronous star-planet systems, and a third less
populated regime of potentially synchronized systems. No synchronous
star-planet system with a period higher than 40 days has been detected yet.
This landscape is different from eclipsing binary systems, most of which are
synchronized. We suggest that planets in a stable asynchronous spin state
belonging to star-planet systems in a supersynchronized regime offer the most
favourable conditions for habitability.Comment: 15 pages, 1 figure in main paper, 6 supplementary figures. Published
in Nature Astronomy, May 202
Physiological Correlates of Volunteering
We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation