All Questions
Tagged with exoplanets exoplanets or
122 questions
-4
votes
1
answer
120
views
Why do we refer to life on Earth when we talk about life on other planets? [closed]
I have always had thoughts about extraterrestrial life and I wonder why researchers largely compare the conditions for existence of life to that on the Earth?
Is it impossible that on a remote ...
- 109
0
votes
2
answers
261
views
In searching for an exoplanet by observing transitions, isn't it rather rare that an orbital plane would line up with Earth?
Given that we are at a random orientation to any remote star system, it seems to me that there is only a narrow angle at which transits of exoplanets can be observed.
Imagine a large mathematical ...
- 984
0
votes
1
answer
123
views
Fusion inside a planet with high concentration of radioactive elements?
If an Earth-sized or larger planet had sufficiently large amounts of radium, thorium or uranium, couldn't the resulting fission trigger periodic fusion of hydrogen? I'm thinking of fission happening ...
- 140
1
vote
2
answers
1k
views
What is the unit of time "JD" in an astronomical context?
For my high school physics project I am required to research a planetary system. The orbital period of the planets are given in JD. What are these units? I've tried to research it, and I've found it ...
- 135
0
votes
0
answers
38
views
Toroidal planetary systems
Is it possible that two toroidal, rigid, homogeneous planets are forming a system in which the toroids are chained through each other, and during their mutual motion, the planets are never touching ...
- 1,359
0
votes
1
answer
815
views
Where to start, if I would like to run a planet climate simulation? [closed]
I would like to understand the math behind it, and maybe write an own climate simulator program. I know, that it is a really hard subject. But I'm curious, and I would like to learn more about it. But ...
- 307
20
votes
1
answer
2k
views
Can we know if an exoplanet has a magnetic field?
The recent discovery of the exoplanet Proxima b gave rise to several questions concerning its habitability and its potential to host life. A major concern is the huge amount of radiation coming from ...
- 1,264
4
votes
2
answers
184
views
Is it possible to get to get to Proxima B in 30 years?
This morning I read about the discovery of an earth-like planet, Proxima B, being 'just' 4.22 light years away from us. This is quite interesting since the planet is oribiting our closest neighbour.
...
- 143
0
votes
2
answers
549
views
Is there an equation that can estimate chances of alien life in the universe?
Seeing how infinite the universe appears and out of all of those stars, planets, galaxies, there must be other life forms. Mathematically, the odds are very good. Is there a mathematical equation to ...
- 253
1
vote
0
answers
88
views
Locating a possible habitable zone in an ordered hierarchal septenary star system?
I'm writing a story about potential off-world colonization in the dawn of interstellar commerce, and despite such a plot necessitating some degree of FTL travel I'd like to keep the rest of my science ...
- 117
15
votes
2
answers
2k
views
What is the farthest planetary body or star system object we have observed using visual light?
What is the farthest object which we can get a direct Detailed visual image of using visible light which appears more than just a dot and falls into one of the following categories:
Planet
Satellite
...
- 838
0
votes
1
answer
256
views
What is the difference between habitable and Goldilocks zone?
If I am right, Habitable Zone means that a planet is on such a distance from its Star which makes it good candidate for supporting some sort of life.
But then what is Goldilocks zone and how is it ...
- 117
3
votes
3
answers
255
views
Simulation of relativistic probe passing through an external solar system
I recently read about the Breakthrough Initiative to launch "StarShot", a nano-probe that is designed to travel to Alpha Centauri at $0.2c$. One of the challenges to be solved involves the precise ...
3
votes
1
answer
2k
views
How is the stellar flux for exoplanets calculated?
I have noticed that in many Wikipedia articles, the stellar flux received by each planet is stated. I tried to calculate this stellar flux from the given data, but the results didn't seem to be ...
- 3,934
78
votes
6
answers
10k
views
How can we see planets thousands of light years away but don't know if there are more planets in the solar system?
That is basically my question, it arose when I saw an article (here is the scientific paper, which should be free to read) saying two Caltech scientists might have found the 9th planet of the solar ...
- 1,768
1
vote
1
answer
2k
views
Finding radius of an exoplanet's orbit knowing orbital period and star's mass [closed]
I've been stuck on this question in an assignment for a while now, and I can't seem to find anything on the internet that either deals with a question in which more values are provided, or where the ...
- 11
6
votes
2
answers
1k
views
How does rogue planet PSO J318.5-22 stay 800ºC?
According to this article, the rogue planet (meaning a planet which does not orbit a star) PSO J318.5-22 has a surface temperature of 800ºC and weather that features molten iron rain. Without a star ...
- 738
3
votes
1
answer
87
views
Have we observed sufficient extra-solar planetary systems to establish a planetary distribution pattern? [duplicate]
From Kepler And Extra-Solar Planetary Observations
As of January 2015, Kepler and its follow-up observations had found 1,013 confirmed exoplanets in about 440 stellar systems, along with a further ...
user81619
3
votes
3
answers
2k
views
Lift and drag coefficients on other planets
The question I'm trying to answer seemed simple: how hard would it be to fly on a planet with lower gravity but also thinner atmosphere compared to Earth. If the answer could hint me at how much ...
- 33
2
votes
2
answers
16k
views
How does a planet's size really affect its surface gravity?
If we located an exoplanet whose diameter was $x$ times that of the Earth's in size, and which for simplicity appeared to have an identical composition to that of Earth, then its mass might be taken ...
- 281
10
votes
2
answers
2k
views
How can a gas giant be about the same size but six times more massive than Jupiter?
I've just read this article: http://www.sci-news.com/astronomy/science-kepler-432b-new-super-jupiter-exoplanet-02490.html
And I wondered how this could be possible?
Maybe it's because this gas giant ...
- 1,643
0
votes
1
answer
2k
views
Calculating eccentric anomaly using the Newton-Raphson method
Yesterday I asked a question on calculating the eccentricity of an exoplanet only knowing the radial velocity vs. phase graph an the mass of the star (question). The answer I got helped me a lot, but ...
- 27
2
votes
1
answer
219
views
Calculating the size of exoplanets with moons
When astronomers detect an exoplanet using its transit and calculate its size to be, say twice the earths size, do they have any way of knowing that its actually not a slightly smaller planet with a ...
- 303
2
votes
1
answer
4k
views
Calculating the eccentricity of an exoplanet
I'm wondering how to calculate the eccentricity of an exoplanet by its radial velocity vs. phase graph. To clarify my question I will take an exoplanet called WASP-14b 2 as an example (http://...
- 27
3
votes
1
answer
728
views
Exoplanet Mass-Radius Diagram
I'm currently studying the following diagram:
But I'm not entirely sure I understand what's going on. Is it just, that most exoplanets discovered, is pretty much made up of Hydrogen and Helium ? And ...
- 2,577
2
votes
1
answer
1k
views
Density of a planet
I was wondering, how would you find out about the mass and the density of a planet and what the planet is made of?
Finding out about the mass might be possible, because you can observe the movements ...
- 253
2
votes
2
answers
297
views
Habitable zones around other stars
I have a question about measuring the boundaries of habitable zones on other planets.
Is it okay to assume that, if Sun's habitable zone starts at a distance $R_0$ and its luminosity is $L_0$, we can ...
- 125
2
votes
1
answer
124
views
Global Circulation Model of tidally locked planets for PC?
Is there some free simple Global Circulation Model that can handle tidally locked planets and can be easily compiled and used on a PC computer? It does not have to be very precise, I am interested ...
- 444
14
votes
2
answers
2k
views
What would we see if we looked at our Solar system from 2,000 light years away with our current technology?
Assuming the tables were turned and we would live in a system like Kepler-422/423/424, some 2,000 ly away. If we'd look at the Solar system with a telescope like Kepler and using techniques like ...
- 209
1
vote
1
answer
143
views
Non-discoveries by the Kepler space telescope: exomoons, co-orbital planets, trojans
I am just reading the review article Advances in exoplanet science from Kepler (arxiv preprint: http://arxiv.org/abs/1409.1595), and I found a remarkable paragraph (last paragraph in section "...
- 781
1
vote
1
answer
189
views
Multiple planets orbiting a star
One way of detecting exoplanets orbiting around a star is the Radial velocity method.
Can this be used to detect multiple planets? Wouldn't the star orbit the center of mass of the whole system with ...
- 344
2
votes
2
answers
157
views
For a planet which has a temperature gradient, hot in the center and cooler on the surface, why do we get absorption lines?
For a planet which has a temperature gradient, hot in the center and cooler on the surface, why do we see absorption lines?
Similarly, why do we see emission lines if the planet is hot on the ...
- 1,015
1
vote
1
answer
85
views
Spectroscopy and the current state of our ability to determine the composition of extra-solar planets
I was interested in learning more about the status of our scientific understanding and technological instruments regarding extra solar spectroscopy.
I am motivated by this almost 3 year old question/...
0
votes
1
answer
44
views
how find resonance in extrasolar planet? [closed]
I make this program, i have a 2xN matrix in which the columns are the ID of planets and their period, the rows are the number of planets, for istance something like that:
...
1
vote
1
answer
4k
views
Is there a simple formula for calculating semimajor axis bounds of "habitable zone"?
I understand that an accurate determination of the bounds of the "habitable zone" for a given stellar system depends on a large number of factors, including many beyond characteristics of the parent ...
- 5,169
5
votes
1
answer
167
views
Are the known exoplanets representative of the population of exoplanets?
An article about the recent release of a large number of confirmed exoplanets states that most of the 715 newly announced exoplanets orbit very close to their host stars.
Do the theories predict ...
- 16.7k
0
votes
1
answer
200
views
Is there any other solar system in the universe?
Is there any other solar system far away from ours in the universe?
Why don't we expect another solar system based on another star similar to sun in the universe?
If so, Why probably there wouldn't ...
- 1,653
7
votes
2
answers
510
views
Earliest terrestrial planet?
If I've understood correctly, the heavier elements needed for terrestrial planets such as iron can only form in supernova.
If that is indeed true, how long since the beginning of the universe would ...
- 692
8
votes
1
answer
4k
views
What is the percentage of stars with planetary systems
We have discovered quite a number of exoplanets to date. The Kepler spacecraft has examined 150,000 stars and found 1,059 exoplanets.
We know that Kepler, as well as all other exoplanet searches to ...
- 11.2k
10
votes
2
answers
315
views
How close would Earth have to be for us to detect it was habitable, and then inhabited?
Given our current technology (or technology that is near implementation), how close would a clone of our Solar System (and so also Earth) have to be to us in order to detect that the cloned Earth was ...
- 6,987
4
votes
2
answers
227
views
Is it possible that only one hemisphere of a planet has an atmosphere?
Suppose there is a tidally locked planet orbiting a star. The planet's surface consists of a global ocean, that is, liquid water. At the inner hemisphere the temperature is so high that the water is ...
- 11.3k
7
votes
1
answer
420
views
Are there rogue planets between Sun and Proxima Centauri?
Would we be able to detect (via emitted radiation, or its gravity) a rogue planet between us and Proxima Centauri? How big would that planet need to be?
- 275
3
votes
4
answers
401
views
Gas giant evolution over lifetime
In various types of stars, one can learn how they evolve differently, depending on factors such as their size and chemistry. Some stars have a short lifetime and others much longer.
But, what is ...
- 53
1
vote
2
answers
396
views
Is there anyone calculate the probability of extrasolar planets?
After reading an recent news "Stargazers capture first picture of a planet with two suns – just like Luke Skywalker’s home planet of Tatooine in Star Wars", I am thinking that: can we calculate the ...
- 116
9
votes
2
answers
299
views
Word for the star around which an exoplanet orbits:
Is there accepted nomenclature for the star around which a particular exoplanet orbits? Meaning, if I were to say "The exoplanet blah blah blah's (noun)" what noun would I put there? Sun? Star? ...
- 147
9
votes
3
answers
1k
views
Why is planet CFBDSIR2149-0403 hot?
According to a BBC report
Astronomers have spotted a "rogue planet" - wandering the cosmos without a star to orbit - 100 light-years away.
...
The proximity of the new rogue planet has ...
- 7,308
4
votes
1
answer
536
views
What day/night cycles, climate and seasons would experience Alpha Centauri Bb inhabitants?
Alpha Centauri Bb is an exoplanet orbiting Alpha Centauri B. It is asserted that given the close distance to the star the planet should be tidally locked.
The orbiting period of the planet is about ...
- 11.3k
2
votes
1
answer
154
views
Alpha Centauri Bb: Comparing astrometric precision vs Doppler precision
How do you compare astrometric precision vs Doppler spectroscopic precision?
In particular, will the Gaia spacecraft to be launched next year be able to confirm the existence of Alpha Centauri Bb? I.e....
- 869
14
votes
1
answer
2k
views
Do any naked-eye stars have planets
Are there any known exoplanets around naked-eye stars? I know that Fomalhaut has a planet, and Vega has a dust belt that may be a protoplanetary disk or even analogous to our Kuiper belt. What else is ...
- 4,543
7
votes
1
answer
1k
views
Stability of moons around tidally locked exoplanets
Can someone send me pointers to work (either theoretical or simulations)
showing (in)stability of satellite orbits around tidally locked exoplanets?
I want to know firstly if satellite orbits can ...
Kamal Ali