Teegarden's Star and its two planet candidates

[stevebowers]

Here's Andrew LePage on the habitability of these worlds.
https://www.drewexmachina.com/2019/06/19...dens-star/

The discovery of Teegarden’s Star b and c presents scientists with yet another opportunity to study nearby “temperate planets” in hopes of more fully characterizing their actual properties. Based on what we known today, it appears likely that both of these new finds are rocky worlds like the Earth with much smaller probability that they are mini-Neptunes. The prospects for the potential habitability of Teegarden’s Star b do not appear to be as good as those of planet c owing to former’s close proximity to the inner limit of the habitable zone as well as being more exposed to any enhanced activity earlier in the evolution of Teegarden’s Star – this despite the record setting Earth Similarity Index (ESI) value for planet b. Still, these new finds do seem to have reasonable prospects of being habitable given the gaps in our understanding of planetary habitability especially for ultracool dwarfs like Teegarden’s Star. Future study of these and similar exoplanets should help provide greater insights in this question. And with hints of a third exoplanet in this system (not to mention the possibility of still others), Teegarden’s Star could be as an important laboratory for studying the evolution of exoplanets orbiting ultracool dwarfs as the better known TRAPPIST-1.

Planet c looks promising then- although I'm still concerned abut CO poisoning. Note that carbon monoxide is a very common compound in the universe, but is degraded by any hint of UV light - so is only likely to be the dominant component in cool systems like this.

[BorkLord]

I was thinking about the star when I came across this, so I whipped this up to bump the article: Because there’s already many ideas of what to do here I believe we should combine them to create an interesting history. Of course we need to alter them so that they can fit together. The AIs could get there first, but then are followed shortly after by a human expedition. The AIs tolerates this, and the two cultures tenuously coexist, before stronger connections are made over 100s of years and gradually once society is made. (Using Aldrin Cyclers to go between the two planets). Then a while later they or another group create a neogen whale/shark ecology.


Of course, this is just one version of events, and is really meant to bring more discussion. 

[MiyuwiAuthor]

Here's some old threads with ideas regarding Teegarden's Star:

https://www.orionsarm.com/forum/showthread.php?tid=4382
https://www.orionsarm.com/forum/showthread.php?tid=4810

[ProxCenBound]

Interestingly, since those older discussions, an additional terrestrial planet has been discovered exterior to the habitable zone, planet d. There's also a candidate between b and c, with a 7.7 day period.

https://www.aanda.org/articles/aa/full_h...33-23.html