37
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Kepler space telescope undetected planets
That's right. The inclination of the orbital plane around stars is considered to be random throughout the galaxy, thus the planets we can detect by the transit method is just a tiny fraction of the ...
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17
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"Periapsis" or "Periastron"?
No. These words are English, not Greek. "Periapsis" means the point on the orbit when the two bodies are at their closest. It doesn't matter if this good Greek or bad Greek, it is correct ...
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17
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How does NASA figure out orbital period and mass data for planets and other celestial bodies?
I'll take a small exception to @JamesK's answer about what NASA does and doesn't do. The Jet Propulsion Laboratory is part of NASA and one of the many invaluable contributions they've made to ...
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11
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Why does Kepler's "Big Picture" of comet 67P look so strange? And what is the significance?
One thing to keep in mind is that the Kepler instrument is not a telescope like Hubble. It is a photometer and though it uses CCDs to look at the sky, it doesn't return a picture in the usual sense. ...
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10
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According to my calculations Jupiter's moons do not follow Kepler's 3rd law - Why is that?
Kepler's third law is that $R^3/P^2$ is a constant. However it is not a universal constant; it depends on the mass of the body that is being orbited.
$$\frac{R^3}{P^2} \simeq \frac{GM}{4\pi^2},$$
...
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8
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Kepler space telescope undetected planets
Yes.
The probability of a transit taking place is something like $r/a$, where $r$ is the stellar radius and $a$ is the radius of the planetary orbit.
If you assume that planet orbits are randomly ...
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8
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Where can I find online-available datasets for the KIC 8462852?
I would suggest to follow the instructions given here: NASA how to get Kepler lightcurves
There you find the links to two archives, where you can enter the name of the source "KIC 8462852" ...
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7
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How does NASA figure out orbital period and mass data for planets and other celestial bodies?
Yes, NASA uses indeed Kepler's 3rd law to calculate the orbital periods of planets and other objects in the solar system. If you go to NASA's Horizons Website and generate orbital data for a planet ...
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6
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What caused instant jumps and exactly flat periods in Kepler's light curves?
There are two separate points of interest you're looking at so I'll separate this into sections.
Sudden Drop at Day 1559
As near as I can tell, this is the result of a quarterly roll of the ...
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6
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"Periapsis" or "Periastron"?
A disclaimer first - I am not an astronomer, but I am a Greek with some ancient Greek language knowledge.
"Periapsis" is definitely ancient Greek and it derives from peri+apsi (περί+αψη). ...
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6
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Calculate eccentric anomaly using Kepler's equation
The difference in values seems to be only $2\pi$, or one complete turn. So your value seems to be correct.
Here is my calculation:
Jupiter was at perihelion on March 17th 2011, which is 2672 days ...
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5
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Unbelievably high masses/ densities in NASA website data
Starting from the index you mentioned, I clicked through the links for some individual planets, which in turn link to discovery papers or other relevant observations. For planets around Kepler-23, -24,...
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5
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Can one approximate the semi-major axis of an orbit as the average orbital distance for eccentric orbits?
The maths says that the semi-major axis is not a good measure of average distance for high eccentricity (elliptical) orbits.
There are basically two ways to measure this : (1) an average over the ...
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5
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Are gas giants actually rare?
There is an observational bias and it is taken into account when you see inferences about planet frequency.
The methods to find planets are inherently biased towards finding large, close-in planets. ...
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5
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Keplerian Elements for Approximate Positions of the Major Planets
I believe you are right, this is extracted from the "Explantory supplement to the Astronomical Almanac (2006?)" (although it might date back to the 1960s...)
For example a similar PDF ...
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5
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How did Kepler come to the potencies in his Third Law?
If you plot the log of the period against the log of the semi-major axis then it is obvious that $P^2 \propto a^3$. Any other power law relationship simply wouldn't fit.
The following passage (from ...
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5
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Whether the comet is moving in an elliptical or hyperbolic orbit around the sun?
This might not be so hard after all.
Below I show the math for the analytical solution for a Kelperian orbit; the catch is that it's only analytical for $t(\theta)$ and not $\theta(t)$ but that ...
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4
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Can one approximate the semi-major axis of an orbit as the average orbital distance for eccentric orbits?
Just to provide an analytical formula for @uhoh's correct time-averaged distance, here the derivation of $\langle r\rangle_t=1+\epsilon^2/2$:
$$a=1 \qquad c=e\qquad b=\sqrt{1-e^2}\\
\vec{r}=(\cos \...
4
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Just how "locked" are resonant-chains of exoplanets thought to be? (e.g. K2-138 and TOI-178)
Short Answer: MMR (Mean Motion Resonance) chains seem to be mostly unstable over the lifetime of a planetary system, since we suspect most planetary systems begin in some resonance lock, but we ...
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4
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Kepler's second law of motion
That is not correct.
The area is the total area between the two radius lines, so there is a curved side.
Imagine you have two points almost 180 degrees from each other. Using just a triangle, the ...
4
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What does "forward facing" mean for space telescopes?
This can best be described by two slides from this presentation.
"Forward-facing" implies looking towards Earth in the spacecraft's orbit, in the direction of the spacecraft's velocity vector:
"...
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4
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Has star KIC 8462852's 3 year long Kepler-fading continued after the primary Kepler mission ended?
Well "if no known astrophysical model can explain it" then nobody told Wright & Sigurdsson (2016) who, cognisant of Montet & Simon's results, explore a number of astrophysical models. They ...
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4
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Getting light curves from Kepler/K2
Go to the Kepler/K2 MAST database https://archive.stsci.edu/kepler/data_search/search.php or https://archive.stsci.edu/k2/epic/search.php
Search on a temperature ($T_{\rm eff}$) range: e.g. for K-...
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4
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Data to "check" Kepler’s first law
Great project! and welcome to Stack Exchange. I'll post a short answer but I think someone can add a more detailed, thorough and insightful answer.
I think that website is not well suited, so I'll ...
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3
votes
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Hot and "warm" Jupiters expelling terrestrial planets?
It's not proof that they've ejected other inner planets, because there are plenty of other explanations for why we haven't observed companions. Steffen et al. (2012) analyzed Kepler data - likely some ...
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3
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How does gyrochronology deal with differential rotation and axial tilt?
Gyrochronology uses the rotation periods of stars, caused by rotational modulation by starspots to estimate a stellar age. In the absence of differential rotation, the rotation axis inclination has no ...
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3
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What telescopes have observed anomalies in the light curve of Tabby's star, KIC 8462852?
I do not know whether complimentary observations of the light curve are being done, but I will try to answer the rest of the question.
Is it easy to observe the light curve with ground-based ...
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3
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Where can I download processed data of the Kepler telescope?
What you are looking for is here. http://archive.stsci.edu/kepler/search_retrieve.html
This one is good for exoplanet light-curves https://exo.mast.stsci.edu/
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How to find the mass of a planet not knowing the gravitational constant?
How can I do this by not knowing the gravitational constant?
Sarcasm: You could do what Henry Cavendish did, which was to measure how the horizontal deflection rather heavy balls separated ...
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