Teegarden’s Star

Hi everyone

I can remember reading Nemisis by Isaac Asimov along with a detailed article in the magazine Astronomy about the smallest stars Red Dwarfs sometime in the 90s. This sparked an interest in these small and interesting stars, I have been reading and studying them ever since. I have been thinking along with many others about their prospects for life and even extra-terrestrial civilization’s. Fast forward to the present day and technology has revealed systems of Terrestrial worlds are very common around these numerous and long lived stars. In fact not finding system of Planets would now be considered unusual. I’m also currently reading Proxima the story was written before the discovery around Proxima Centauri which is interesting in itself. Let now have a look at another amazing system around a Red Dwarf.

Teegardens star is a solar neighbour, and similar in size to Trapist-1 being just large enough to make it onto the main sequence, so this is a Red Dwarf star one of the smallest possible. Detailed observations have revealed two planets similar in size to our own Earth receiving enough flux to be potentially very interesting worlds. There are even hints of a 3^rd planet much colder and further out.

As usual my two favourite Author’s Paul and Andrew have written excellent posts on this amazing discovery (See links below) in fact Andrew sums it up well with the following.

“A thorough assessment of the habitability of any extrasolar planet would require a lot of detailed data on the properties of that planet, its atmosphere, its spin state, the evolution of its volatile content and so on. Unfortunately, at this very early stage, the only information typically available to scientists about extrasolar planets are basic orbit parameters, a rough measure of its size and/or mass and some important properties of its sun. Combined with theoretical extrapolations of the factors that have kept the Earth habitable over billions of years (not to mention why our neighbors are not habitable today), the best we can hope to do at this time is to compare the known properties of extrasolar planets to our current understanding of planetary habitability to determine if an extrasolar planet is “potentially habitable”. And by “habitable”, I mean in an Earth-like sense where the surface conditions allow for the existence of liquid water – one of the presumed prerequisites for the development of life as we know it. While there may be other worlds that might possess environments that could support life, these would not be Earth-like habitable worlds of the sort being considered here.”

So what are these planets like? It’s interesting to speculate with our best knowledge on what they could be like. I’ve actually been meaning to do a write up on the subject of how to classify exo planets and my own approach is similar to the one employed by PHL. It’s very unlikely the Planets around Teegarden Star could be classed as having an Earth like biosphere, But lichens, extremophile and simple single celled life could well be right at home on and under the surface, in geothermal locations under any seas or oceans that might exist. The best surface conditions for life on these planets might well resemble the high arctic environments here on Earth. So these planets are not going to resemble the Amazon jungle, or the African Savannah however conditions could be better than on Mars or Europa.

It’s interesting to speculate what could happen if the Planet B was more Earth like. Let say it did have an Earth like Atmosphere, flares and the solar wind no having eroded it away. A magnetic field and geologic activity similar to Earth along with continents and an ocean. While tidally locked the Atmospheric tides along with the other planets cause it to rock back and forward shifting the hot sub solar point around on the surface. Let’s assume advance plant life has evolved and uses infrared for photosynthesis. Animals also evolve and one evolves in to an intelligent species. With another nearby planet there would be a big incentive to develop a space programme, which would also protect against comets and asteroids. Life around a solar mass G type star would seem extreme to them, but using telescopes similar to ourselves they start monitoring a bright G type star 12 light years away, in a few years’ time they would be in for a major discovery.

Now to find the time to get back to reading Proxima

Please note:

The quote about planets is from Andrew Le page @ Drew Ex-Machina

Thanks to Andrew B for giving this write up a peer review before I posted.

My standard caveat that these are the views of a learned amateur, not a professional in the sector, applies as always.

The above post/email/update represents my own words, views, research and opinions, unless stated otherwise the above work represents my own writing. I’ll give credit or thanks if I have used or represented other people’s words and/or opinions. The links and references listed below represent the work and research of the respective author’s.

Questions and constructive criticism are always welcome, however I don’t believe anything written here by myself is any reason for impolite behaviour.

Thanks for your time and I hope you have enjoyed reading.

Full links and references below:

Research paper

The CARMENES search for exoplanets around M dwarfs. Two temperate Earth-mass planet candidates around Teegarden's Star

M. Zechmeister, S. Dreizler, I. Ribas, A. Reiners, J. A. Caballero, et al.

https://www.aanda.org/component/article?access=doi&doi=10.1051/0004-6361/201935460

Habitable Planet Reality Check: The Earth-Size Planets of Teegarden’s Star

https://www.drewexmachina.com/2019/06/19/habitable-planet-reality-check-the-earth-size-planets-of-teegardens-star/

CARMENES: Two Habitable Zone Planets around a Nearby Red Dwarf

https://www.centauri-dreams.org/2019/06/18/carmenes-two-habitable-zone-planets-around-a-nearby-red-dwarf/

A Nearby System with two Potentially Habitable Worlds

http://phl.upr.edu/press-releases/pr_draft_tee4321