Questions tagged [exoplanet]
Questions regarding planets that lie outside the Solar System.
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Where did TRAPPIST-1a go?
According to the NASA announcement and the Wikipedia article on TRAPPIST-1, the planets around the TRAPPIST-1 star are named TRAPPIST-1 b through h. What happened to "TRAPPIST-1 a"?
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If Alpha Centauri A's solar system exactly mirrored our own, what would we be able to detect?
Suppose there was an exact replica of our solar system 4.4 ly away (people included). What would we be able to detect and with what telescope(s)? Which planets? Could we detect radio transmissions and/...
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Is it odd that our Sun has so many planets?
The internet is abuzz with the new evidence of the possible ninth planet in our Solar System. With those nine objects, the asteroid belt, the Kuiper belt, and everything else in our Solar System - the ...
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Which of the planets would be detected if they were exoplanets?
An (almost-)omnipotent being selects the solar system, presses Ctrl+C, and then Ctrl+V several times, creating copies at distances of 5, 500, 50.000, and 5.000.000 light-years away. All in a direction ...
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Terrestrial Exoplanet Skies – I've Built a Visual Sky Chart. Is it Accurate?
I'm an artist (and science enthusiast) and I've been trying to find a comprehensive resource that would help me clearly identify likely sky colors (as perceived by human vision) for exoplanets that ...
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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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Is Jupiter still an anomaly?
I remember a few years ago hearing that Jupiter was an anomaly in the landscape of exoplanets. Back then, most Jupiter-mass planets discovered were Hot Jupiters, orbiting very close to their host star....
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Do these results mean that I have found this exoplanet?
Yesterday I was going through the TESS mission data on mast portal and after applying some filters I found some data. I started analyzing that data using the lightkurve library.
plot without using the ...
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how far away could we detect that Earth has life?
My guess is that life bearing planets are too far apart to be detected. I think we can only find the ones within a sphere around our planet that is 100s of light years in diameter but I suspect life ...
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How are the compositional components of exoplanet atmospheres differentiated?
How are exoplanetary atmosphere compositional spectra distinguished from those of the parent star(s), from the composition of the planetary surface or any other factor? Is it actually possible to ...
user8
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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 ...
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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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How was Trappist-1 discovered?
I was going through all the questions in this community related to TRAPPIST-1 in order to know how planets TRAPPIST-1b to TRAPPIST-1h were discovered, but there aren't any.
How were they discovered?
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Hypothetical trans-Neptunian planets orbiting the Sun
The planet HD 106906 b was found at 650 AU from its home star, a star not so different from the Sun. Fomalhaut b is also a young planet that is orbiting very far away from its star.
These two planets ...
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Why are most discovered exoplanets heavier than Earth?
Looking at all discovered exoplanets (4393 exoplanets), I found than only 17 of them (less than one percent!) have masses less or equal to Earth's mass. Why so?
Is it because it is very difficult to ...
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What does forward modeling mean?
In my research on exoplanets, I have heard many people talk "forward modeling of exoplanet atmospheres". I don't know what the "forward" means in "forward modeling" and how it compares with "reverse ...
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How many sun-like stars are there in the universe?
After yesterday's announcement of the Kepler telescope finding a huge amount of newly observed exoplanets, i saw a headline claiming that as much as 22% of sun like stars in the universe have planets ...
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Exoplanet dip in transit light curve when the planet passes behind the star
In the animation below, I don't understand why the brightness slightly decreases when the planet is behind the star.
Where does this effect come from?
user16492
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Is there a gas giant orbiting TRAPPIST-1?
I would like to know if besides these planets, astronomers have discovered a gas planet like Jupiter in this system and if on these planets could exist life without a comet protector like Jupiter does ...
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What practical considerations are there for amateur observations of transiting exoplanets?
Obviously, I am not referring to actual viewing of the exoplanets themselves, but detecting their effects on the brightness of the light emitted from the parent star (as in the diagram below from The ...
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How hot can a planet be?
Given that some exoplanets, particular "Hot Jupiters", orbit very closely to their parent star, how hot can these planets become?
What is the hottest exoplanet discovered so far?
user8
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What is the most extreme weather found on another planet?
On Venus, there is really inhospitable weather, as well as within the gas giants in our solar system. Are there examples of even more extreme weather on planets found in other solar systems than ours?
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Do any known exoplanetary/solar bodies have "annular" eclipses similar to Earth's?
This was somewhat inspired by this question but is a bit different: I am interested in if there are any known systems in which the angular size of the eclipsing object is almost the same as the ...
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Do celestial objects need to be big to have liquid water on their surfaces?
I mean no asteroid, planetoid that I am aware of has water on its surface. It is way more common to see ice in it. So I figured that the size of the celestial body has something to do with the cycle ...
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Orbital velocity of a planet - why is my calculation off by about 10%?
I am not sure if I am doing something wrong, or misunderstanding Reider and Kenworthy (2016).
I'm just trying to reproduce the orbital velocities listed in Table 1. The second paragraph of Section II ...
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How would we detect an Earth doppelganger planet?
With our current technology, or technology available in the near future (up to 2025), how would we detect a planet exactly like our own, and how close would it have to be to be detectable?
Which ...
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What is the current accepted theory for the fate of hot Jupiters?
It is well established that one main feature of many hot jupiters is their close proximity to their parent star, usually the equivalent of being within the orbit of Mercury. So, these planets are gas ...
user8
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Is it possible for planetary rings to be perpendicular (or near perpendicular) to the planet's orbit around the host star?
Is it possible for planetary rings to be perpendicular (or near perpendicular) to the planet's orbit around the host star?
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Is there enough data in light coming from distant exoplanets for Earth-orbiting telescopes to take a high-resolution photo of it?
NASA’s James Webb Space Telescope has taken very blurry "photos" of exoplanets around distant stars, such as the exoplanet HIP 65426 b, in different bands of infrared light:
My question is, ...
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Statistics of elements abundance in exoplanets
Recently, I encountered the concept of carbon planets - planets, which would be, unlike the Earth, formed mostly by carbon, instead of oxygen, silicon and magnesium. (I am not counting iron, which is ...
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When will we be able to detect Earth-sized exoplanets?
I have heard that the only planets able to be seen outside the Solar system are Jovian-sized planets with the occasional detection of planets three times the Earth's size. But, as far as I know, we ...
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What percent of planets are in the position that they could be viewed edge-on from Earth? (and thus able to undergo transits)
Star number 12644769 from the Kepler Input Catalog was identified as
an eclipsing binary with a 41-day period, from the detection of its
mutual eclipses (9). Eclipses occur because the orbital ...
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Is the surface of TrES-2b actually dark?
The exoplanet TrES-2b is known as the darkest planet ever found, reflecting <1% of the light that hits it.
What does it mean in respect to the surface? What would we see below the atmosphere of ...
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Are there any planets or moons denser than Earth?
Earth has the highest density out of all planets, planetoids and moons of our planetary system, and also has a higher density than the Sun. Do we know any exoplanets or moons denser than Earth?
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Is the measurement of distance and position of remote celestial bodies accurate?
Considering that light is affected by gravity, how accurate are measurements of distant stars and galaxies?
When light passes through objects with great mass, such as Jupiter size planets, stars, or ...
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Would an exoplanet without axial tilt have no seasons?
Would an Earth analog exoplanet which rotates around a solar analog, but without axial tilt, have no seasons?
Would it be similar to how Los Angeles does not have very noticeable seasons compared to ...
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Could it be possible to detect planets from stars that went supernova through the resulting nebula shape?
It ocurred me, if a star with at least one planetary companion undergoes a nova or supernova, we shoud expect the debris to be deflected to some degree, on exit. To ilustrate it, first let's take the ...
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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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Is it possible for a moon to orbit a planet floating free in the galaxy rather than orbiting a star
This article got me thinking, can a planet hold a moon in orbit if it is just floating in the galaxy by itself not as part of a star system? Can a celestial body even qualify as a planet if it is ...
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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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How close are we to having the technology to measure planetary obliquity for exoplanets?
As far as I can tell, we do not yet have the precision to even put reasonable bounds on an exoplanets obliquity, but wikipedia seems to indicate that this may be possible in the "near future." It ...
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Why there are no terrestrial planets with a subsurface ocean?
Subsurface oceans in satellites are pretty common: Europa, Enceladus, Ganymede, Callisto, maybe Pluto... This is due to tidal heating of their host planet, Jupiter and Saturn, which heats up the inner ...
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What is the orbital path of the newly discovered star-less planet PSO J318.5-22?
Recent results from Institute for Astronomy at the University of Hawaii at Manoa claim that there is a Jupiter-sized gas giant planet that is independent of a star about 80 light-years from Earth.
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How is an exoplanet characterised as "Earth-Like"?
Which features or characteristics are taken into account to characterize an exoplanet as "Earth-Like"?
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Why hasn't VLBI been used to try and image giant exoplanets?
A Jupiter-sized object at 10 pc subtends an angle of 0.0001 arcseconds (100 micro-arcsec) at the Earth. The Event Horizon Telescope interferometry network is capable of a (demonstrated) angular ...
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The battle over Gliese 581 and Gliese 667C?
In 2014, Robertson et al. made a case that stellar activity is masquerading as planets (here and here) for these well-known systems. In both cases, they claim that the only real planets discovered so ...
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Are there any Stars we know don't have planets?
We have been looking for planets around other stars for a while (see related https://space.stackexchange.com/questions/1484 ) and we are finding lots of planets, some of them are Earth like According ...
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How would a person know if a planet is orbiting a binary star?
I read in Neil deGrasse Tyson's book Astrophysics for People in a Hurry that scientists can tell if a star has a planet orbiting it because the light appears to shake.
So if in the case of a binary ...
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How do we know that an exoplanet is tidally locked to the parent star?
Often in discussing exoplanets we hear that they are close to the parent star (usually a red dwarf) but then there's a caveat that the planet is tidally locked to that star and that that fact severely ...
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Are there plans to detect life on Earth from the outer solar system?
This has been kicking around in my head for a while. We've been detecting planets for decades by observing regular dips in starlight from many light years away as a planet transits its host star. I've ...
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