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6 votes
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Total apparent magnitude of eclipsing binary system

Without information about stellar radii, I think it's reasonable to assume $R_A \approx R_B$. Then your equation becomes $$ m_p - m_s = -2.5 \log \frac{F_A}{F_B} $$ and you can compute $k$ and the ...
Mike G's user avatar
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5 votes

The definition of eclipsing binary star systems

I assume that the diagram indicates what the observer sees (if they had a big enough telescope!). i.e. The viewpoint is nearly in the orbital plane but not quite. Why then are the eclipses asymmetric, ...
ProfRob's user avatar
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5 votes
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Which things can LIGO see that LISA can't, and vice-versa?

Gravitational wave detectors have a frequency range that they are sensitive to. In the case of LIGO it is about 10Hz to 1kHz. The lower limit is imposed by seismic noise, the upper limit by "shot ...
ProfRob's user avatar
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5 votes
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What is the v sin i parameter?

That said, a common velocity observed in binary systems (or also generally multiple systems and exoplanet systems) is the radial velocity of the component(s) around the barycenter. That's the velocity ...
planetmaker's user avatar
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5 votes
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Orbital speeds of Components of Binary System

Use the vis-viva equation for 2 bodies: $$v^2=G(M_1+M_2)\left(\frac{2}{r}-\frac{1}{a}\right)$$ where $v$ is the relative velocity, $G \approx 887.125 \frac{\text{AU}}{M_\odot}(\text{km}/\text{s})^2$ ...
Connor Garcia's user avatar
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4 votes
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How to phase fold data when periodicity change is known as d$\omega$/d$t$?

If $\omega(t)$ is $$ \omega(t) = \omega(T_0) + \int_{T_0}^{t} \frac{d\omega}{dt}\ dt$$ then the phase $\phi(t)$ is $$ \phi(t) = \phi(T_0) + \int_{T_0}^{t} \omega(t)\ dt$$ And your phase-folded ($0 \...
ProfRob's user avatar
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4 votes

Observing eclipsing binaries

The AAVSO eclipsing binary section is a good place to start reading. Their how-to articles address eclipsing binary specific issues such as predicting times of minimum. To get a list of observable ...
Mike G's user avatar
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4 votes

Observing eclipsing binaries

www.skymaponline.net might be the one you want. Main goal when taking images in terms of timing and exposition: 1. Choose time with good sky condition (e.g., clear sky, no wind) 2. Expose long enough ...
Kornpob Bhirombhakdi's user avatar
4 votes

What is the spectral reflectance of starlight in a close binary?

Stars are far from perfect blackbodies due to scattering/reflection. This is especially true for hotter stars, because of all the free electrons, but even cooler stars can reflect a significant ...
Ken G's user avatar
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4 votes
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Variable Types of Stars

It seems to me that you're mostly asking about star naming conventions, which is unfortunately a difficult thing to master because there are many many conventions. What makes this process difficult is ...
zephyr's user avatar
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3 votes
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What determines how accurate a particular method is at finding the period between Lomb-Scargle and String Length Minimization?

I think they are just not the best period-finding algorithms. They are too simple. For high signal-to-nose data with SINGLE periods they seem to work ok, but the problem is always with low-quality ...
JOAQUÍN HERNÁNDEZ's user avatar
3 votes
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Eclipsing binaries - definition with inclination

The condition that a binary eclipses is (approximately) just a piece of trigonometry, assuming the stars are spherical and in circular orbits (this is quite likely for close binaries). The condition ...
ProfRob's user avatar
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3 votes

Which data should I use to take the fast Fourier transform (FFT) to find time period for eclipsing binaries?

For this, you should create a lightcurve, a graph of brightness over time, to view the data. For Kepler data, the bjd(date) column is the time in BJD. The dtr_flux stands for detrended flux, meaning ...
AstronomyGeek's user avatar
3 votes
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V471 Tauri's circumbinary brown dwarf non-observation; Applegate, or over-restrictive assumptions?

For all of these direct imaging results, the critical parameter is the contrast as a function of separation. This lets you know how much fainter an object you can see around the much brighter primary ...
astrosnapper's user avatar
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3 votes

How is phase defined in a binary orbit with eccentricity?

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 ...
Daddy Kropotkin's user avatar
3 votes

How to determine temperatures for a binary system?

Yes, you're exactly on the right track. There are several methods people use to estimate the temperature from the color indices, but most of them estimate the temperature from the average index (i.e. ...
mknote's user avatar
  • 133
3 votes
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How can eclipsing binaries be used to gauge distances?

Most distance methods are luminosity-based: you measure an object's flux, assume it has a particular luminosity, and then determine the distance from that using the inverse-square law. So the question ...
Peter Erwin's user avatar
  • 17.2k
2 votes

How can eclipsing binaries be used to gauge distances?

The key here is mass. In nonbinary systems (or other external factors) it can be a bit tough to determine mass of a star. You just see a point source of light; we can get spectral features which can ...
Justin T's user avatar
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2 votes

How is phase defined in a binary orbit with eccentricity?

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. ...
Connor Garcia's user avatar
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2 votes
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Time domain astronomy and fastest eclipsing binary ZTF J1539+5027 (+20 mag, 6.91 minutes): How to measure its minimum brightness?

Unless I've done my maths wrong, the period of total eclipse is about 18 seconds. The CHIMERA camera at Mt Palomar, the instrument which followed up the discovery of this system, can take exposures at ...
ProfRob's user avatar
  • 155k
2 votes

period of an eclipsing binary

The period (at least in physics) is defined the time an oscilating system needs to get back to its starting point (for a sinus curve its 2*pi). Now when they say an eclipsing binary has a period of T ...
RononDex's user avatar
  • 466
2 votes
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Determining masses from radial velocity curves of eclipsing binaries

No, it is correct. The inclination of an eclipsing binary can be estimated from the light curve (and is likely to be close to 90 degrees in order to produce an eclipse). The radial velocity curves can ...
ProfRob's user avatar
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1 vote
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Binaries: mass and distance constraints

If you have an astrometric binary (one where both components can be resolved in an image - for example Sirius AB), then knowing the distance to the binary system can tell you what the physical scale ...
ProfRob's user avatar
  • 155k
1 vote

What determines how accurate a particular method is at finding the period between Lomb-Scargle and String Length Minimization?

I do think the previous response contains almost all you need to know, so I won't write everything, only a little bit of additional information I did find useful at least in my case. There are two ...
Kacper Rutkowski's user avatar
1 vote

What is the v sin i parameter?

$v \sin i$ is the parameterised amount of rotational broadening that is required to match the spectrum being considered. $v$ is the equatorial velocity of a star and $i$ is the (generally unknown) ...
ProfRob's user avatar
  • 155k
1 vote

Semimajor axes data from Kepler Eclipsing Binary Catalog

The reason the KEBC doesn't have semi-major axes is because it's based entirely on photometric data with no EB modeling done. Determining the SMA requires spectroscopic data and EB modeling. ...
mknote's user avatar
  • 133
1 vote

What is the spectral reflectance of starlight in a close binary?

This is a long-standing (and complicated!) problem in modeling eclipsing binary light curves. Here’s a full review from 1985 (with later citations here), which suggests (from a very quick skim) that ...
Eric Jensen's user avatar
  • 4,894
1 vote

What is the spectral reflectance of starlight in a close binary?

Complementing @KenG's answer, Here's an actual datapoint. The new paper in Nature Polarized reflected light from the Spica binary system (downloadable here) is notable in that the measurement of the ...
uhoh's user avatar
  • 30.6k
1 vote

What percent of planets are in the position that they could be viewed edge-on from Earth? (and thus able to undergo transits)

The answer comes from the number of stars examined by each method. Kepler in the first part of its mission examined 150,000 stars. After the extended mission it has examined 503,506 https://en....
TazAstroSpacial's user avatar

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