# Tag Info

## New answers tagged exoplanet

15

A rough back-of-the-envelope way of seeing what's going on... The tidal force is due to the difference in gravitational force, so follows an inverse cube law: $$F_\mathrm{tide} \propto M_\ast R^{-3}$$ where $M_\ast$ is the stellar mass and $R$ is the distance. So at the same distance from a less massive star, the tidal force will indeed be weaker. But ...

3

This answer applies to the simplest case: a static binary and a point source. In the binary case, $u(t)$ describes how close each point in the source trajectory comes to (what you have defined as) the origin of the binary axis. The solution is non-trivial. It involves finding the roots of a 5th order complex polynomial. You can look for example at how ...

2

The only way to answer the question about stability is to do the integration, because this problem does not have an analytic solution. There are approximate solutions for the stability of two-planet systems (although these are based on a somewhat weaker constraint that allows the outermost object to escape to infinity) but they do not necessarily generalise ...

1

(Some of) These plots are incorrect. Whilst Rayleigh scattering has a steep dependence on wavelength $(\propto \lambda^{-4})$, it cannot scatter what is not there. There is almost no blue light at all coming from stars with $T_{\rm eff} < 3500$ K. A detailed description of the problem with your calculations(?) is given here with regard to a red giant ...

1

I think the star,its halo and cloud can't be darker than the sky color even early M type still look blindingly bright orange-red on the sky not dim orange-red. The sky color, if heavier i think it will look more "desaturate"(brighter too but not bright to the point it's brighter than the star) and thecolor shift toward the red side(you are correct) that ...

4

> Do other stars have similar gaseous-to-rocky ratios among their planets? For any given stellar system, are there typically as many gaseous planets as there are rocky planets? With the current instruments and methods we have, we can only access certain population of exoplanets. Terrestrial-mass exoplanets are quite hard to find hence we have more ...

6

I am not using TESS to find planets, but I'm reasonably sure that the answer is that nobody has looked very carefully at all the data yet. The TESS data comes in two flavours. There were a subset of about 200,000 stars that were observed with a 2 minute cadence. These targets were chosen to be a combination of bright and small, heavily weighted towards ...

1

The important thing to bear in mind is that WASP-76b is a gas giant (at the time of writing, the NASA Exoplanet Archive gives values of 0.92 Jupiter masses and 1.83 Jupiter radii, so this planet is much less dense than Jupiter is): there's no solid surface for the iron to build up on. Instead what would happen is that the iron would rain down until it ...

2

FFI means "full frame image". It does not contain any tables, so the unhelpful error message is almost certainly due to that. Chapter 2 of the Kepler Archive Manual is essential reading. Light curve files have a file name suffix of .llc or .slc (long and short cadence), as described in that document, and contain binary fits tables that can be opened and ...

12

Radial velocity Radial velocity might be able to detect Jupiter in the 5 or 500 light-years cases unless the solar system were oriented close to face-on. There is nevertheless the potential for confusion with the solar activity cycle at a similar period (this issue has come up for a couple of extrasolar Jupiter-analogues), which may require a very long ...

21

The distance moduli at 5, 500, 50,000 and 5,000,000 are -4.1, 5.9, 15.9 and 25.9 respectively. We add that to the absolute visual magnitude of the Sun, 4.8, to get apparent magnitudes of 0.7, 10.7, 20.7 and 30.7 respectively. Most planets are detected by the Doppler wobble in the parent star or if the planet transits in front of the parent star. Some are ...

3

It's usually a good idea to use the main page and follow links there instead of guessing URL; a search for "kepler telescope data" and "tess telescope data" quickly revealed these links: Kepler: https://keplerscience.arc.nasa.gov/data-products.html which links for some data to https://exoplanetarchive.ipac.caltech.edu/index.html TESS: https://heasarc.gsfc....

13

There is no unique definition of Earth-like and it depends on what characteristics are important in the context of discussion. The most simple one is to just compare radii and masses. That is observationally sensible as radius is directly deducable from transits (assuming stellar size known) and mass is often an accessible properties for transiting planets ...

3

The term "stellar component" refers to a part ("component") of a system that is in the form of one or more stars. For example, the Alpha Centauri system has three stellar components: Rigil Kentaurus, Toliman and Proxima Centauri. The planet Proxima Centauri b is also a component of the Alpha Centauri system but it is not a stellar component because it isn't ...

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