3 research outputs found
The rapidly pulsating sdO star, SDSS J160043.6+074802.9
A spectroscopic analysis of SDSS J160043.6+074802.9, a binary system
containing a pulsating subdwarf-O (sdO) star with a late-type companion, yields
Teff = 70 000 +/- 5000 K and log g = 5.25 +/- 0.30, together with a most likely
type of K3V for the secondary star. We compare our results with atmospheric
parameters derived by Fontaine et al. (2008) and in the context of existing
evolution models for sdO stars. New and more extensive photometry is also
presented which recovers most, but not all, frequencies found in an earlier
paper. It therefore seems probable that some pulsation modes have variable
amplitudes. A non-adiabatic pulsation analysis of uniform metallicity sdO
models show those having log g > 5.3 to be more likely to be unstable and
capable of driving pulsation in the observed frequency range.Comment: 14 pages, 12 figures, accepted for publication in MNRAS, 2009
September
Children's Height and Parental Unemployment: A Large-Scale Anthropometric Study on Eastern Germany, 1994-2006
The average height of children is an indicator of the quality of nutrition and healthcare. In this study, we assess the effect of unemployment and other factors on this variable. In the Eastern German Land of Brandenburg, a dataset of 253,050 preschool height measurements was compiled and complemented with information on parents' schooling and employment status. Unemployment might have negative psychological effects, with an impact on parental care. Both a panel analysis of districts and an assessment at the individual level yield the result that increasing unemployment, net out-migration and fertility were in fact reducing height. Copyright 2009 The Authors. Journal Compilation Verein für Socialpolitik and Blackwell Publishing Ltd. 2009.