Long-term photometry of the eclipsing dwarf nova V893 Scorpii: Orbital period, oscillations, and a possible giant planet

The cataclysmic variable V893 Sco is an eclipsing dwarf nova which, apart from outbursts with comparatively low amplitudes, exhibits a particularly strong variability during quiescence on timescales of days to seconds.The present study aims to update the outdated orbital ephemerides published previously, to investigate deviations from linear ephemerides, and to characterize non-random brightness variations in a range of timescales. Light curves of V893 Sco were observed on 39 nights, spanning a total time base of about 14 years. They contain 114 eclipses which were used to significantly improve the precision of the orbital period and to study long-term variations of the time of revolution. Oscillations and similar brightness variations were studied with Fourier techniques in the individual light curves. The orbital period exhibits long-term variations with a cycle time of 10.2 years. They can be interpreted as a light travel time effect caused by the presence of a giant planet with approximately 9.5 Jupiter masses in a 4.5 AU orbit around V893 Sco. On some nights transient semi-periodic variations on timescales of several minutes can be seen which may be identified as quasi-periodic oscillations. However, it is difficult to distinguish whether they are caused by real physical mechanisms or if they are the effect of an accidental superposition of unrelated flickering flares. Simulations to investigate this question are presented.Comment: Accepted for publication in Astronomy & Astrophysics (acceptance date: 2014, March 31

Whose Law Is It Anyway? The Cultural Legitimacy of International Human Rights in the United States

Whose Law Is It Anyway? The Cultural Legitimacy of International Human Rights in the United States on ResearchGate, the professional network for scientists

Where the Twain Shall Meet: Standing and Remedy in Alaska Center for the Environment v. Browner

In 1994, the Ninth Circuit affirmed standing for citizens to sue to compel the EPA Administrator to undertake a statewide TMDL program. Although the citizens had standing for only some of the water-quality-limited waters in Alaska, the court held that the underlying cause of action was the EPA\u27s failure to initiate the TMDL process for Alaska. This Note proposes that the court improperly reasoned its way to the correct holding. Like the EPA, the court confused standing to sue with the ultimate scope of the remedy. This Note proposes a three-step analysis to consider issues of standing and remedy. The first step is to determine the scope of the underlying action by analyzing the legal duty that forms the basis for the claim. This scoping action is critical since it serves as the referent for the next two steps. The second step is to determine whether the plaintiff has standing with respect to the underlying action. If the court decides on the merits of the case that the plaintiff should prevail, the third step is to determine the appropriate remedy. In this step, the court starts with the underlying cause of action and incorporates other factors as appropriate. This three-step analysis decouples the standing and remedy analyses and should lead to better reasoned opinions. I. INTRODUCTION In Alaska Center for the Environment v. Browner (ACE III), 1 the Ninth Circuit distinguished between standing to sue and the ultimate scope of the remedy. The court affirmed standing for a group ..