Analysis of Pulsating White Dwarf Star Light Curves

Analysis techniques are presented for extracting the frequencies contained in the light curves of pulsating white dwarf stars. In several surface temperature regimes, these astronomical objects are unstable to gravity mode pulsations which result in brightness variations corresponding to the periods of the excited modes. There is a rich array of possible periods with values ranging from about 100 to 1000 seconds. Mode periods present in the light curve are detected by undertaking a Fourier analysis of the time series light curve; theoretical models of the star can be refined with this information. The Fourier analysis needs to take into account such things as finite length, data gaps and the presence of noise

The post-outburst pulsations of the accreting white dwarf in the cataclysmic variable GW Librae

We present new time series photometry of the accreting pulsating white dwarf system GW Librae obtained in 2012 and 2013 at the University of Canterbury Mt John Observatory in New Zealand. Our 2012 data show the return of a ∼19 min periodicity that was previously detected in 2008. This pulsation mode was a dominant feature of our quality 2012 May data set, which consisted of six contiguous nights; a detailed analysis indicated a degree of frequency variability. We show by comparison with the previously identified pulsation modes that this periodicity is best explained as a new mode, and that the quasi-stability of the periods appears to be a general feature of the pulsations in these systems. We also find a previously unreported 3-h modulation period, which we believe to be related to the known two and four hour periods of so far unknown origin

Russian Public Accepts Putin's Spin on Ukraine Conflict

A new Chicago Council-Levada poll reveals the Russian public appears to be buying Putin's explanation for "military operation" in Ukraine.While the whole world seems to be watching the Russian "special military operation" in Ukraine, a new joint survey by the Chicago Council on Global Affairs and the Levada Center conducted March 24–30 shows that most people living in Russia are not following these events closely. Nevertheless, a majority of Russians say they support their country's military action—with just over half strongly backing it. For the most part, Russians think these actions are being taken to protect and defend fellow Russians and Russian speakers in Ukraine, to protect Russia itself, or to "denazify" Ukraine—storylines that have been amplified by the Russian government's media apparatus. But as the conflict drags on, it may become more difficult to sustain this support, especially as the casualty rates are uncovered and the economic repercussions of the Western sanctions begin to more seriously affect Russian households

GW Librae: Still Hot Eight Years Post-Outburst

We report continued Hubble Space Telescope (HST) ultraviolet spectra and ground-based optical photometry and spectroscopy of GW Librae eight years after its largest known dwarf nova outburst in 2007. This represents the longest cooling timescale measured for any dwarf nova. The spectra reveal that the white dwarf still remains about 3000 K hotter than its quiescent value. Both ultraviolet and optical light curves show a short period of 364-373 s, similar to one of the non-radial pulsation periods present for years prior to the outburst, and with a similar large UV/optical amplitude ratio. A large modulation at a period of 2 h (also similar to that observed prior to outburst) is present in the optical data preceding and during the HST observations, but the satellite observation intervals did not cover the peaks of the optical modulation so it is not possible to determine its corresponding UV amplitude. The similarity of the short and long periods to quiescent values implies the pulsating, fast spinning white dwarf in GW Lib may finally be nearing its quiescent configuration.Comment: 6 figures, accepted in A

Kant, Morality, and Hell

In this paper I argue that, although Kant argues that morality is independent of God (and hence, agrees with the Euthyphro), and rejects Divine Command Theory (or Theological Voluntarism), he believes that all moral duties are also the commands of God, who is a moral being, and who is morally required to punish those who transgress the moral law: "God’s justice is the precise allocation of punishments and rewards in accordance with men’s good or bad behavior." However, since we lack a strict proof of God's existence, we can still fulfill our duties from the motive of duty. if we did know that God exists, then this would undermine our pure moral motivation to do our duty, since we would have an even stronger interest in pleasing God through our good conduct. The effect of undermining our pure moral motivation would be to make us less eligible for divine reward, since God rewards us for doing our duty from the motive of duty

Multicolor Observations of a Planetary Transit of HD 209458

We present B, V, R, I and Z-band photometric observations of HD 209458 during the transit by its planetary companion on UT 1999 November 15 with the University of Hawaii 0.6m and 2.2m telescopes and the High Altitude Observatory STARE telescope. The detailed shape of the transit curve is predicted to vary with color due primarily to the color-dependent limb-darkening of the star, but potentially due as well to the effect of color-dependent opacity in the planetary atmosphere. We model the light curves and present refined values for the transit timing and orbital period, useful for planning future observations of the planetary transit. We also derive significantly improved measurements of the planetary radius, R_p = 1.55 +/- 0.10 R_Jup, stellar radius, R_s = 1.27 +/- 0.05 R_Sun, and orbital inclination, i = 85.9 +/- 0.5 deg. The derived planetary radius favors evolutionary models in which the planet has a low albedo.Comment: 6 pages, 3 figures, accepted for publication in ApJ Letter

The development of metaphorical language comprehension in typical development and in Williams syndrome

The domain of figurative language comprehension was used to probe the developmental relation between language and cognition in typically developing individuals and individuals with Williams syndrome. Extending the work of Vosniadou and Ortony, the emergence of nonliteral similarity and category knowledge was investigated in 117 typically developing children between 4 and 12 years of age, 19 typically developing adults, 15 children with Williams syndrome between 5 and 12 years of age, and 8 adults with Williams syndrome. Participants were required to complete similarity and categorization statements by selecting one of two words (e.g., either “The sun is like ___” or “The sun is the same kind of thing as ___”) with word pairs formed from items that were literally, perceptually, or functionally similar to the target word or else anomalous (e.g., moon, orange, oven, or chair, respectively). Results indicated that individuals with Williams syndrome may access different, less abstract knowledge in figurative language comparisons despite the relatively strong verbal abilities found in this disorder

New Pulsating DB White Dwarf Stars from the Sloan Digital Sky Survey

We are searching for new He atmosphere white dwarf pulsators (DBVs) based on the newly found white dwarf stars from the spectra obtained by the Sloan Digital Sky Survey. DBVs pulsate at hotter temperature ranges than their better known cousins, the H atmosphere white dwarf pulsators (DAVs or ZZ Ceti stars). Since the evolution of white dwarf stars is characterized by cooling, asteroseismological studies of DBVs give us opportunities to study white dwarf structure at a different evolutionary stage than the DAVs. The hottest DBVs are thought to have neutrino luminosities exceeding their photon luminosities (Winget et al. 2004), a quantity measurable through asteroseismology. Therefore, they can also be used to study neutrino physics in the stellar interior. So far we have discovered nine new DBVs, doubling the number of previously known DBVs. Here we report the new pulsators' lightcurves and power spectra.Comment: 15 pages, 2 figures, 3 tables, ApJ accepte