All Questions
14 questions
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
8
votes
3
answers
359
views
Is a rogue 'exoplanet' classed as a exoplanet?
Given that the term planet strictly (according to the IAU) refers to a body around the sun, rogue planets can't be called that, so I assume they must be called rogue exoplanets?
But do they even ...
- 6,987
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
4
votes
2
answers
208
views
Are there planets orbiting something else than a star?
Exoplanet is a planet that orbits a star different from our Sun.
Are there any planets (that we know of) which orbit something else? (Like different giant planet or black hole or maybe neutron star.)
- 269
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
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
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
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
0
answers
102
views
What orbit does a planet have to have to be a planet? [closed]
Other questions have dealt with where you could find a planet-like object, and what a planet has to consist of to count as a planet. But this question is directed as what orbit or path an object would ...
- 121
1
vote
1
answer
43
views
Can a planemo turn into a star?
I read this question
Why is planet CFBDSIR2149-0403 hot?
and wonder what will happen to this "planemo". Will it attract more mass as it flows around in the gas clouds in space and eventually light ...
- 439
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
0
votes
2
answers
92
views
Study of exoplanets reaching saturation point [closed]
In recent exoplanet meeting The Next 40 Years of Exoplanets, it was mentioned a few times that the field/topic is becoming saturated.
In what ways is it becoming saturated, and can you see the effect ...
- 235
0
votes
2
answers
67
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 ...
- 500
-1
votes
2
answers
98
views
Did we adapt to Earth or Earth to us? [closed]
I often hear that Earth is a unique planet because it has life and it has its own inhabitance. We also see a proper balance between plants and humans and other animals. Why life is not possible on ...
- 12.1k