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It depends whether you are talking about an eclipsing binary or a visual or spectroscopic binary. For an eclipsing binary, phase zero is mid primary eclipse. For visual or spectroscopic binaries, phase zero is at periastron. A plotted phase on a light curve or a radial velocity curve is given by $$\phi(t) = \frac{2\pi}{p}(t - \tau),$$ where $\tau$ is the ...

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Moreno et al. in their paper Eccentric binaries: Tidal flows and periastron events [2011] define the orbital phase as from -0.5 to 0.5, where periastron is at phase 0, and apastron is at -0.5 and 0.5. Orbital phase here is $\phi = \dfrac{t}{P}$, where time $t=0$ at periastron and $P$ is the orbital period. This definition allows them to plot the behavior ...

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Usually, how is phase=0 defined? It is relative to the line of apses perhaps with phase=0 at periastron? The true anomaly, $\theta$, is the angle between the current location of the orbiting particle and its location in the orbit at which it is closest to the central body (called the periapsis/periastron). The word "phase" is used variously in ...

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I don't feel that ProfRob's answer does the step to advanced LIGO justice. First, it is important to recognize that LIGO, from its inception, was envisioned as a two-stage project. From Caltech`s LIGO lab: ... and in 1989, Vogt, Drever, Fred Raab, Thorne and Weiss submitted a joint Caltech/MIT proposal for LIGO construction to the NSF.The proposal ...

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Tl;Dr: It is a matter of consideration if you want to call Kuiper belt bodies/Oort cloud bodies "asteroids" or not. Long answer: The Oort cloud defines the cosmographic boundary of the Solar System and the extent of the Sun's Hill sphere and hence it is loosely bound to the Solar System, and thus is easily affected by the gravitational pull both of ...

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I think this is largely a matter of what you decide is incremental as opposed to a generational change. The basic location and overall size and detection principle of the interferometers did not change. An important change to the interferometer configuration was the addition of the signal recycling mirror that allows a certain amount of "tuning" of ...

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It seems that the authors are just referring to the accepted model of a pulsar, i.e. a neutron star spinning and emitting beams of radiation at its poles. In that sense, the term is used here no differently than it would be in the context of an isolated pulsar. It's just a very simple way of visualizing why an observer far away appears to see periodic pulses ...

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The GREAT receiver attached to SOFIA to detect far-infrared radiation incorporates elements reminiscent of both radio and optical detectors, but since it works by mixing a signal from a tunable oscillator with the oscillating field from the incoming radiation rather than by the photoelectric effect as in most optical detectors, you might consider it more ...

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