Questions tagged [exoplanet]

Questions regarding planets that lie outside the Solar System.

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5 votes
1 answer
318 views

How are planets detected from the pull their gravity exerts on their parent stars?

"The planets we have so far discovered orbiting other stars were found from the pull their gravity exerts on their parent stars, or from the light they block from their stars when they pass in ...
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5 votes
1 answer
118 views

How to know if an exoplanet is terrestrial?

NASA exoplanet archive, open exoplanet catalog and exoplanet.eu are some of the most famous catalog of exoplanet discovered by all techniques. However, all of these catalogs are missing the ...
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1 vote
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If Ganymede had a thick, Earth-like atmosphere, would the surface be protected from Jupiter's intense radiation?

Obviously, this is a totally hypothetical, alternate version of Ganymede, since it would also need to have more mass and a stronger intrinsic magnetic field to hold onto a substantial atmosphere. But ...
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8 votes
1 answer
551 views

Which of the exoplanets are having retrograde rotation?

By exoplanet, I mean planets outside of our solar system(i.e., planets in other solar systems). If we talk about our solar system, then Venus, Uranus, and Pluto have retrograde rotation. Most of the ...
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3 votes
2 answers
69 views

Fourier analysis of exoplanet transit to determine the number of planets in the system

Although I think that this can be done by simply looking at the transit graph, I was wondering if a Fourier transform of a transit (basically transforming transit depth/amplitude vs time graph to ...
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14 votes
1 answer
1k views

Why use a large separate starshade instead of an occulting disk?

The New Worlds Mission proposal has a large occulter on a different spacecraft from the space telescope to block glare from a star to reveal its planets. What is its advantage compared to a disk on an ...
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3 votes
1 answer
110 views

If you were standing on a habitable moon of a gas giant, what would the planet look like during the day vs the night? [closed]

If you were standing on the proplanetary side of a habitable moon of a gas giant, and the moon had a thick enough atmosphere to make the sky blue, how would the gas giant look during the day? Would it ...
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1 vote
0 answers
16 views

easy curve modeling package for transits that fits the data not just the parameters?

Does anyone have any recommendations for easy-to-use exoplanet transit light curve model fitting packages like batman, but that fits the data, not just the model parameters? Thank you so much. I need ...
3 votes
0 answers
52 views

How to obtain exoplanets transmission spectra from JWST's NIRISS data of WASP96?

I was having a look at JWST's NIRISS data of WASP96 (specifically at the x1dints fits file which should be already calibrated). From this, I would like to obtain a result in a fashion similar to the ...
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7 votes
2 answers
84 views

Is the Michael H. Hart range for the Habitable Zone (Goldlocks Zone) still used?

We're having an argument on another site about the Hart definition of the CHZ. In 1979, Hart provided a very conservative estimate of habitable zone: 0.958 - 1.004 AU. This was used to substantiate ...
3 votes
0 answers
75 views

Could we make ourselves detectable for aliens with JWST-like technology?

The James Webb Space Telescope is going to take spectra from planets during transit in front of their central star. By that, spectral changes can identify if the planet possesses an atmosphere and ...
14 votes
2 answers
2k views

How it is not possible to say if Titius–Bode law is a "coincidence" or not?

From Wikipedia: No solid theoretical explanation underlies the Titius–Bode law – but it is possible that, given a combination of orbital resonance and shortage of degrees of freedom, any stable ...
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22 votes
4 answers
5k views

What's the difference between an exoplanetary transit and eclipse? [duplicate]

This article states Their data contained eclipses for all 25 exoplanets, and transits for 17 of them. This page from NASA explains the difference between an eclipse and a transit: Like an eclipse, ...
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1 vote
0 answers
45 views

Why do we estimate the Minimum mass when we are dealing with exoplanets?

While solving astronomy problems dealing with exoplanets, I always see that the question asks for minimum mass instead of the mass. Why is that so and why is the calculated mass minimum mass? example ...
3 votes
1 answer
55 views

Best way to quantify the tidal stress on an exoplanet?

I'm trying to assess the tidal stresses different exoplanets experience during their orbits. The known parameters are usually mass $M$, radius $R$, eccentricity $e$, orbital period $T$, and semi-major ...
5 votes
1 answer
68 views

Is an extreme precession on a tidally locked planet possible?

Let's assume an exoplanet orbits a red dwarf star closely enough that is tidally locked to it. Is it possible for the planet to have a significant axial precession? If not naturally, is it possible to ...
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0 votes
1 answer
51 views

Data base of exoplanets with common names to use beside Nasa Exoplanet Archive

For a project I am working on, I use data from the NASA Exoplanet Archive at https://exoplanetarchive.ipac.caltech.edu/TAP/sync?query=select+*+from+ps&format=json I take this json data down and ...
1 vote
2 answers
164 views

Astrophysics Ph.D. thesis on intergalactic rogue planets and their habitability; how active is this field of research?

Is the habitability of intergalactic rogue planets something that has been studied a lot? The reason that I'm asking is that I've just started my PhD program last year and I'm wondering/concerned if ...
7 votes
1 answer
116 views

Is one transit enough to be confident that we detected an exoplanet

Everything is pretty much in the title. I was thinking about the transit method and was wondering if the signature of a transit on the light curve of a star is distinctive enough to only need one ...
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3 votes
1 answer
148 views

What is the densest known exoplanet?

55 Cancri e is said to be 60 percent larger in diameter than Earth but have 8 times, the mass, making it twice as dense as Earth, and almost as dense as lead. https://www.space.com/11544-densest-alien-...
3 votes
1 answer
99 views

Accurate formula for calculating the mass of an exoplanet using the transit method

A friend and I did some work on exoplanets with the help of a research institute (IEEC in Spain) for a major high school project. What we did was to "redetect" the exoplanet XO-6b through ...
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0 votes
1 answer
94 views

Can we use atmospheric retrieval techniques on stars?

Although there are lots of examples of atmospheric retrieval techniques being used on exoplanets, and recently brown dwarfs, I can't find any mention of atmospheric retrieval techniques being used on ...
2 votes
1 answer
41 views

What does "RV model including a GP with a quasi-periodic covariance structure" mean?

A candidate short-period sub-Earth orbiting Proxima Centauri says: 4.1 Simple periodogram analysis ]We first consider a very simple pre-whitening procedure applied to the CCF RVs in order to ...
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2 votes
0 answers
51 views

Contradictory errors in python package VESPA

VESPA is a python package that can calculate the False Positive Probability for Exoplanets. Here is the link to the repository https://pypi.org/project/VESPA/ https://github.com/timothydmorton/VESPA ...
1 vote
1 answer
188 views

What is a Keplerian shear

I was reading an article on Gas Giants and how some form close to their host star. One line in the article says: A region of the proto-planetary disk will be susceptible to gravitational instability ...
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0 answers
113 views

How massive can a carbon planet be?

A carbon planet is a theoretical type of planet with more carbon than oxygen. How massive can a carbon planet be? Could you have a neptune-like planet except with all the water replaced with ...
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3 votes
1 answer
109 views

The reason for an exoplanet density increase of planets closer to a star

From the NASA exoplanet archive system it can be seen that in the range of $0.02-0.06~\text{AU}$ distance an exoplanet is to its star, as distance drops down, the planet density increases linearly: A ...
4 votes
2 answers
362 views

Probability of transit of an exoplanet in front of its star

I'm trying to calculate the probability of transit of an exoplanet in orbit around a star of diameter $d$, at a distance of $4d$ from its centre. Here's what I did: In this figure, we are only ...
1 vote
0 answers
43 views

Power law of object mass in Milky way

Red dwarfs are more common than larger stars. Does this trend continue to smaller objects? If you take every "condensed object" from dust grains through asteroids, planets, and stars in the ...
2 votes
0 answers
27 views

Infrared ozone line detection

I was recently reading Jack R. Woods' response on this forum: Could the James Webb Space Telescope detect biosignals on exoplanets? In an ideal situation (say looking at absorption lines of a super-...
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2 votes
2 answers
217 views

Would a planet orbiting black hole be detectable?

Usually missions like Kepler are finding exoplanets orbiting (the barycenter of systems related to...) stars at distances that are not common if compared with the Solar System. This finding (as I ...
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0 votes
0 answers
22 views

Lightcurve Labels

I had a query regarding light curve labels. As simple as it goes we can plot time (MJD, BJD, etc) on X-axis. Also, I know we can plot magnitudes on Y-axis. Again I've seen papers showing Relative flux ...
4 votes
1 answer
73 views

Can we measure planetary Love number of exoplanets?

I understand that Love number is the ratio between the tide raising potential to the actual deformation of the body, however, I'm not sure if there are ways to detect the Love number from observations ...
2 votes
0 answers
43 views

Can distribution of stars / planets formation be a long-tailed one?

We know that peak of star formation already passed 10.1146/annurev-astro-032620-021910 and it looks like peak of planet formation occurred slightly after formation of Earth 10.1017/S1473550415000208 ...
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23 votes
10 answers
6k views

Is the closest planet to another planet always the innermost planet?

In our Solar system Mercury is not only the closest planet to Earth on average but also, for the same reason, the closest planet on average to all other planets (Jupiter, Neptune, etc...). Does that ...
10 votes
1 answer
2k views

What is sin i in this graph and why is it there?

This is some data presented in a lecture on exoplanets that depicts the distribution of the sizes of super-Earths in comparison to the mass of Jupiter. I would like to know what the argument of the ...
1 vote
1 answer
54 views

Which studies prior to 2018 "claimed to find evidence of extragalactic planets in the Andromeda galaxy"? Which instrument was used?

After the first round of popular news items about the "first extragalactic exoplanet" discovery, CNET's Did astronomers find the first planet outside of the Milky Way? It's complicated ...
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1 vote
0 answers
30 views

Which University of Oklahoma research purported to "detect thousands of extragalactic planets back in 2018"? Which instrument was used?

After the first round of popular news items about the "first extragalactic exoplanet" discovery, CNET's Did astronomers find the first planet outside of the Milky Way? It's complicated ...
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24 votes
4 answers
8k views

Is there any planet bigger than a star?

Or a star smaller than a planet? Which star and planet would be an example of this?
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6 votes
2 answers
98 views

After only one eclipse of its X-ray bright primary, how can astronomers estimate the first extragalactic exoplanet's period to be about 70 years?

Phys.org's Astronomers may have discovered the first planet outside of our galaxy links to Di Stefano et al. 2021 A possible planet candidate in an external galaxy detected through X-ray transit (...
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1 vote
1 answer
91 views

Was the First Extragalactic Planet discovered in Andromeda Galaxy

In the news today, they announce a first possible planet outside the Milky Way galaxy has been spotted, in the Whirpool Galaxy. https://www.bbc.co.uk/news/science-environment-59044650 Surely the ...
1 vote
1 answer
42 views

How often does the configuration of the Trappist-1 system repeat

My question is simply how long it takes for the 7 known planets in Trappist-1 to be in the same configuration in relation to their host star, and to each-other. Those seven planets are in a 2:3:4:6:9:...
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2 votes
2 answers
187 views

What are opinions of most planetary scientists on this study (link below), were there already some complex reviews in scientific journals?

I remember this two year old article from Universe Today about this study, "Stepwise Earth oxygenation is an inherent property of global biogeochemical cycling", by Lewis J. Alcott, Benjamin ...
3 votes
1 answer
67 views

Shortest and longest wavelengths at which exoplanets have been resolved from their primaries?

Phys.org's Radio signals from distant stars suggest hidden planets summarizes the Nature Astronomy paper The population of M dwarfs observed at low radio frequencies (also in arXiv) but this is an ...
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4 votes
1 answer
299 views

Why was there a gap in exoplanet detection in 2015?

The question How has the number of known TNOs evolved over time? contains a link to this image: Number of extrasolar planet discoveries per year through April 2018, with colors indicating method of ...
8 votes
3 answers
2k views

What precisely leads to planets like COCONUTS-2b to orbit so far away from their host stars, 6000 AU in its case?

Taking our Solar System as an example, most gas giants formed relatively close by (a few AU) and drifted away to reasons I don't know, from an explanation I recall reading. Simply orbiting a few AU ...
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1 vote
1 answer
49 views

Maximum distance at which planetary atmospheres can be analyzed during transits?

Is there a limit for how far away you could make a spectroscopic analysis of a planet when it transits its star, to detect bio markers and industry markers? What would the limit be with current ...
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1 vote
1 answer
80 views

Incorrect best period fit over phase-folded data

I am using the astropy Lomb-Scargle periodogram here, https://docs.astropy.org/en/stable/timeseries/lombscargle.html to get the best period fit using its model() method for simulated data given in ...
2 votes
0 answers
43 views

Precision of orbital period of exoplanets vs solar system planets (Extrasolar Planets Encyclopedia)

I noticed that the Extrasolar Planets Encyclopedia lists the orbital period of L 98-59 b in days to 7 decimal places. Can astronomers really measure orbital period of exoplanets to greater precision ...
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1 vote
1 answer
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Can a terrestrial planet orbit an icy planet (or vice versa)?

I know that the composition of planets is dependant on the equilibrium temperature at its orbit - for example, if below a certain temperature, water and other volatiles become solid, allowing them to ...
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