0
votes
2answers
35 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
vote
1answer
28 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 ...
0
votes
1answer
25 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
1answer
45 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 ...
7
votes
2answers
94 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 ...
6
votes
1answer
256 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 ...
4
votes
2answers
79 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 ...
4
votes
1answer
193 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 ...
4
votes
0answers
62 views

Are there certain alignments in planetary orbits that create interesting effects in the moons or planets?

We have some interesting examples such as Mercury's perihelion The planet Mercury is especially susceptible to Jupiter's influence because of a small celestial coincidence: Mercury's perihelion, ...
0
votes
2answers
66 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 ...
7
votes
3answers
59 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 ...