Questions tagged [exoplanet]
Questions regarding planets that lie outside the Solar System.
375
questions
3
votes
0answers
21 views
If all the Trappist-1 planets are tidally locked, which ones may have temperate zones?
Since all the Trappist-1 planets have circular orbits, it is entirely likely that all them are tidally locked.
If so, which ones of the planets may have temperate zones either on the bright or dark ...
1
vote
1answer
45 views
IAU 2018 Exoplanet definition
In 2018 the IAU produced a definition of an exoplanet:
The current official wokring definition of an exoplanet as amended by IAU Comission F2: Exoplanets and the Solar System in August 2018, reads as ...
3
votes
1answer
53 views
Lightkurve nan values after bin light curve
I am using lightkurve 2.0.2 library with Python 3.8.5 and astropy 4.2 for processing exoplanet transits. However when I want to bin light curve to fixed number of points, all values in ...
5
votes
1answer
113 views
Why was Neptune rather than Uranus chosen as an archetype?
The largest exoplanets are typically called Jupiter-like planets, or hot/cold Jupiters. Since Jupiter is the largest most massive planet in our Solar system, it makes sense that it would be chosen as ...
2
votes
2answers
205 views
Would it be possible to detect a magnetic field around an exoplanet?
Of course, we can't fly a magnetometer next to an exoplanet to measure the magnetic field, but might it be possible to find indirect evidence (e.g. polar auroras) of a magnetic field generated by an ...
1
vote
0answers
60 views
Strange matter objects other than neutron stars?
This question is about celestrial objects which are composed by exotic matter, and exotic matter I define as
states of matter that are not commonly encountered such as Bose–Einstein condensates, ...
3
votes
2answers
69 views
When examining an exoplanet's atmosphere is the star's emission spectra or planet's light used?
My understanding of the main method we use to figure out an exoplanet atmosphere composition is that when a exoplanet transits their sun, visible light passes through the planet's atmosphere, and ...
1
vote
1answer
60 views
How to track orbit of an exoplanet?
I was wondering if there is an established method to keep track of the orbit of an exoplanet assuming we know a - the semi-major axis of the orbit, e - the eccentricity of the orbit, and i - the ...
15
votes
1answer
929 views
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?
3
votes
1answer
49 views
Eccentricity of Exoplanets
The field of astrobiology specifically discovering other planets that revolve around the sun-like star (also known as Exoplanets) has risen since 1990, but certain orbits of exoplanets are observed to ...
3
votes
0answers
48 views
New method for exoplanet detection?
Could it be possible to detect exoplanets that have an abundance of iridescent minerals by analyzing their star's spectra over time as the angle in observation would lead to changes in absorbed ...
1
vote
0answers
26 views
Using the 'exoplanet' module to fit a radial velocity curve for a binary star system
As part of a project, I am trying to fit a radial velocity curve using the below tutorial for the binary star system (EBLM J0608-59):
https://docs.exoplanet.codes/en/stable/tutorials/rv/
I have the ...
10
votes
1answer
384 views
What are the challenges in finding Earth-like planets via the radial velocity method?
[I have re-asked this, because it was a good question by @Banyan, which was deleted whilst I was composing an answer.]
Most exoplanets that are found by the radial velocity ("Doppler wobble")...
2
votes
1answer
56 views
Did we find any exo–dwarf-planet?
We have discovered thousands of exoplanets so far. Do we categorize them into planets and dwarf planets, too?
3
votes
1answer
77 views
Why does the exoplanetary system TOI-178 challenges current theories of planet formation?
I am excited reading the news about ESA's latest exoplanet discovery using CHEOPS. The system TOI-178 consists of (at least?) five planets, following a 18:9:6:4:3 pattern. In the press release, the ...
10
votes
4answers
3k views
Why can't we build a huge stationary optical telescope inside a depression similar to the FAST?
So first we'll have to find a natural depression or we should create one. I understand you can only see a single portion of the sky since it can't be moved, so my money is on creating an artificial ...
2
votes
0answers
44 views
Abundance of penitente ice formations in the solar system
When researching for my question on extraterresitral snow, I learned about a rare snow formation called penitente which seems to be found on various (dwarf) planets, like Earth, Mars, and Pluto. ...
5
votes
0answers
122 views
Extraterrestrial snow?
What do we know about extraterrestrial snow? On which (exo)planets or (exo)moons do we have direct hints for its existance? This is indeed a children's question, but I struggle to answer it ...
7
votes
3answers
557 views
Can we visually perceive exoplanet transits with amateur telescopes?
Is it possible for an amateur astronomer to visually perceive an exoplanet transit by the change of brightness of the star via observations spaced over time, or is the variation of the brightness too ...
14
votes
2answers
5k views
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?
2
votes
1answer
40 views
Calculating the Solar Day of an Exoplanet?
I am currently in the process of compiling a list of stars and their planets, given the information in the European Star Catalogue found here, but I'm struggling to find out how to calculate a planets ...
2
votes
1answer
50 views
Why doesn't star size distribution conform to space rock size distribution?
The number of space rocks is exponentially related to the size of the rocks. There are more small space rocks than big ones. Stars are most commonly the size of the sun, big and smaller stars are rare,...
4
votes
1answer
153 views
Current best-known Drake Equation values?
Frank Drake's equation is used to estimate $N$ the number of civilizations we might be able to communicate with in our galaxy:
$$N = R_\star f_p n_e f_l f_i f_c L$$
where:
$R_\star$ is the average ...
3
votes
2answers
139 views
How difficult is it for an amateur to discover a new exoplanet or astronomical object?
I recently read about precovery, where plates or images of an object predating its discovery are used to precisely determine its orbit. It occurred to me that it might be possible that some objects ...
20
votes
1answer
3k views
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 ...
1
vote
0answers
20 views
How do HabEx's internal coronagraph and external starshade work together and complement each other? What is it that each can do that the other can't?
Limits of space telescope? links to the video 4 Future Space Telescopes NASA wants to build and that page links to The New Great Observatories. These cover the four space-based instruments proposed by ...
0
votes
1answer
39 views
Identifying cluster of exoplanets between Deneb and Vega
I noticed an interesting patern of exoplanets.
Is this a known phenomenon?
6
votes
1answer
90 views
How do scientists differentiate between a total and a partial transit of a planet passing in front of its star?
Say there's a star in our local neighborhood with a Jupiter-sized planet orbiting around it. This planet's orbit happens to lie approximately in our line-of-sight – we can only see a quarter of it ...
2
votes
0answers
22 views
The electron–cyclotron maser emissions from Earth
The first-ever detection of radio signals caused by the electron–cyclotron maser mechanism outside of the Solar System, on Tau Bootis b was recently published (here). This phenomenon causes huge radio ...
3
votes
1answer
217 views
Minimum distance between planets
In our solar system, MOIDs (minimum orbital intersection distance) of different planets reach a minimum of ~30 million miles (Mercury and Venus). However, other star systems have more compact planets. ...
4
votes
2answers
112 views
Probability of planets in binary star systems?
There is much fiction on binary stars with planets, for whatever reason, and this keeps supporting the popular impression that those systems are frequent. Indeed, the methods for identifying ...
3
votes
0answers
38 views
Simulating oceans and ice sheets on other planets or moons?
From my friends in geosciences I learned a lot about General Circulation Models (GCMs) (for Earth's atmosphere and oceans). I also learned about ice sheet models for floating ice (like sea ice or ...
1
vote
1answer
73 views
What would be the year length of a habitable planet of 40 Eridani A?
The planet Vulcan, in Star Trek, is one of the most famous fictional planets.
The length of a Vulcan year comes up in my answer at:
How old was Spock in Star Trek while he was serving on the ...
3
votes
1answer
143 views
Are planet-destroying quakes possible or observable?
The Gutenberg-Richter-Law is a very-well studied relationship between the magnitude and total number of (earth)quakes. In theory, there is no upper bound for the size of a quake other than the size of ...
3
votes
1answer
81 views
Would the electron cyclotron-maser emission mechanism affect Proxima b's ability to retain an atmosphere?
In a recent arXiv preprint, Pérez-Torres et al. "Monitoring the radio emission of Proxima Centauri" claim the detection of radio emissions synchronised with the orbit of the planet Proxima b....
2
votes
1answer
67 views
Does a continuous deformable mirror cause diffuse reflection?
We have all seen images like this of deformable mirrors:
Continuous deformable mirrors are known to have a higher quality over segmented mirrors, but it seems to me that a continuous mirror (or even ...
1
vote
0answers
26 views
Are falling evaporating bodies (FEBs) and exocomets the same thing? How does one know they're falling and evaporating?
Looking for a (short) list of comets with heliocentric escape velocity I stumbled upon Wikipedia's exocoments which like exoplanets, are bound to other stars. I should have been looking for "...
10
votes
4answers
1k views
Are stars near the ecliptic the only stars from which Earth would appear to transit the Sun?
The majority of exoplanets we have discovered have been found by the transit method, in which a planet passes in front of its parent star and by analyzing the light curve we can deduct its ...
5
votes
1answer
86 views
Why 2014-2015-2016 were the years when the number of discovered exoplanets increased the most?
So, if we look into the cumulative number of exoplanets discovered by year, you can appreciate a huge rise in the number of discovered exoplanets in the years 2014 and 2016:
Credit to NASA Exoplanet ...
0
votes
1answer
44 views
Why do some pulsar planets have designations with a capital letter at the end?
The pulsar PSR B1257+12 has three planets. Most triple-planet system have designation foo b, foo c, and foo d. However, I noticed that the three planets of this pulsar (PSR B1257+12) have a ...
2
votes
0answers
34 views
Help understanding why these two sub-Hill sphere moon stability limits are so different?
Comments under this answer to What orbital period would produce one New Moon (and one Full Moon) each year? What other effects would this produce? link to
Stable satellites around extrasolar giant ...
4
votes
0answers
48 views
Radial velocity exoplanet search - can mathematical details be explained? (Bayesian periodogram MCMC)
Radial velocity (RV) is one of main methods for exoplanet search.
The popular description of the method sounds simple - one should measure periodic Doppler variation of a spectral line of a star and ...
3
votes
1answer
108 views
Is there a public record of planetary disks apart from ours?
Our planetary disk is not aligned with the rest of the galaxy. Are there publicly available records of the orientations of any other planetary disks?
Especially interested in nearby stars - but I'd ...
17
votes
3answers
4k views
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 ...
1
vote
1answer
57 views
Can the Sudarsky's gas giant classification be applied to ice giants?
Based on the temperature of a gas giant around another star, I have come to understand that it is possible to guestimate its appearance; a classification scheme for gas giants developed by David ...
2
votes
2answers
110 views
Technique for folding sparse event data in order to detect an underlying periodicity?
@JamesK's answer to When will the next transit of Earth be visible from Mars? Was the last one really on May 11, 1984? lists dates of 18 transits which I've converted to days since 1500-Jan-01 as
<...
0
votes
2answers
207 views
Calculate mass of exoplanet from transit method
Is there any way to calculate (or at least estimate) mass of an exoplanet from transit method? I know that mass can be calculated with radial velocity method, however I would like to create program ...
4
votes
2answers
86 views
What's still needed before we can observe orbits of exomoons thereby weighing exoplanets?
Comments below this answer to How do we weigh a planet? point out that we currently cannot (or at least have not) detect moons around exoplanets, much less measure the sizes and periods of their ...
6
votes
1answer
280 views
What's the big deal with WD 1856+534 b?
A few days ago (september 2020) a planet candidate was announced orbiting white dwarf WD 1856+534. Some media outlets announce it as the First Possible ‘Survivor’ Planet around a white dwarf, while ...
3
votes
1answer
42 views
I have seen so many articles but how can finding exoplanet density determine composition
I have seen some articles and lectures that state but i cant seem to put my finger on on how does density affect composition and how are you able to determine composition from exoplanet density.
