Proxima Centauri b

[kentonio]

They already said it wasn't spinning didn't they? They sounded pretty sure.

[Lorizael]

It's just a guess based on the age of the star and the planet's distance from it. The radial velocity detection method cannot tell us whether the planet is tidally locked.

[pchang]

Tidal or near tidal locking with an atmosphere would result in very interesting and potentially very powerful weather systems.

[Lorizael]

Yup. There have been a lot of papers recently (because of the "Living with a Red Dwarf" program) looking at atmospheric simulations of exoplanets around stars like Proxima Cen.

One problem with tidal locking, though, is that it reduces the magnetic moment of the planet, and no magnetosphere + lots of solar flares (which stars like Proxima Cen have in abundance) = atmospheric stripping.

[BlackCat]

If it's habitable, average lifetime will be near 2.500 years

[Ben Kenobi]

Lori would it be worthwhile to work this with SPECKTR to try to make images of the planet?

[pchang]

If it's habitable, average lifetime will be near 2.500 years

Umm, how do you get that?

[Dauphin]

Umm, how do you get that?

I would guess the calculation he did was a human lifetime of 75 Earth years = 2,500 years on this planet, given an 11-day year. (365/11*75=~2,500)

[Proteus_MST]

The inhabitants of Proxima b will be constantly partying, because everyday it will be someones elses birthday

[Berzerker]

I understand it orbits a red dwarf

I thought red dwarves are the leftover cores of red giants

so how did this planet survive the red giant phase that close?

or was it dragged closer?

I seriously doubt any water survived

[Lorizael]

Red dwarfs are just low mass stars, busily (well, not so busily) fusing hydrogen into helium just like our star. White dwarfs are the end products of the giant phase (for small enough stars).

[Ben Kenobi]

I thought red dwarves are the leftover cores of red giants

Ahh. Yeah. Stars don't 'evolve into' being Red dwarfs. That's a misconception I had myself. Depending on the mass of the star will determine the temperature at which we see the star.

K dwarfs (orange), are about .5 solar masses to .8 solar masses. M dwarfs are anything 0.5 solar masses to about .075 solar masses. M dwarfs are an enormous, enormous category of stars.

Red giants - or rather their cores, are white dwarfs. They are much, much smaller than most red dwarfs, and much more massive (paradoxically smaller stars are more massive).

[BlackCat]

I would guess the calculation he did was a human lifetime of 75 Earth years = 2,500 years on this planet, given an 11-day year. (365/11*75=~2,500)

Spot on and of course meaningless - half way expected Lori to give me a or two.

[The Mad Monk]

Red dwarves are the oldest stars in the universe, and there will seldom be a time when they are not.

[Proteus_MST]

The discoverers of Promixa b did some more research/calculations and estimate the size of Promixa b to be around 0.94 and 1.4 earth radii.
Depending on the size it could have oceans, similar on earth (if its around the smaller extmates) or even (if the size is around the bigger estimates) even be covered in a 200k deep planetary ocean.
Likewise they assume good chances for an atmosphere in both scenarios

http://phys.org/news/2016-10-planet-star-nearest-sun-oceans.html

http://www.iflscience.com/space/nearby-earthlike-world-proxima-b-may-have-a-global-ocean/