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TRAPPIST-1 now has seven planets. (Possible life?)


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1 hour ago, Cabbink said:

Saw the is on EE. It orbits far, Like h, right? Do you know how big it is, or what it's composition might be?

 

17 minutes ago, Spaceception said:

Oooh, can you elaborate? 

Okay, so with the new publicly available SFF data for Trappist-1, EE user shutcheon was able to analyze the possibility of more planets. He found two possible signals orbiting every 41 and 42 days. I did a further analysis, and the 42-day signal is the most likely to exist, with a sigma value of 7. It's a small, cold world of only about 0.70 (+/-0.03) RE with a temperature of 121oK. 

Speaking of more Trappist planets, there's also the possibility of gas/ice giants (I think ice giants) in the system as well.

https://phys.org/news/2017-09-trappist-earth-like-planets-gas-giant.html

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20 minutes ago, ProtoJeb21 said:

Speaking of more Trappist planets, there's also the possibility of gas/ice giants (I think ice giants) in the system as well.

https://phys.org/news/2017-09-trappist-earth-like-planets-gas-giant.html

Well keep searching! I think, with how the resonances are, there could be another planet at either 53, 64 or 90 days. Remember to check for that. Good luck finding More! :rep:

Edited by Cabbink
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  • 2 months later...

It turns out that, due to sunspots and other stellar activity, the 7 Trappist-1 planets are about 8% SMALLER than originally calculated. In addition, their masses appear more likely to be those given by the initial announcement.

https://arxiv.org/pdf/1711.05691.pdf

Below are the newly calculated physical parameters for the planets based off of the information in the article above.

  • THEROS/B: 0.99912 RE, 0.7082 ME, 3.915 g/cm3, 0.7093752g.
  • AUXO/C: 0.96968 RE, 1.158 ME, 7.00278 g/cm3, 1.2314936g.
  • THALLO/D: 0.71024 RE, 0.34395 ME, 5.29 g/cm3, 0.6818304g.
  • EIAR/E: 0.84456 RE, 0.5242 ME, 4.797 g/cm3, 0.7347672g.
  • IRENE/F: 0.9614 RE, 0.5776 ME, 3.5841 g/cm3, 0.62491g.
  • CARPHOS/G: 1.03684 RE, 1.137 ME, 5.624 g/cm3, 1.0575768g.
  • CHEIMON/H: 0.65504 RE. No mass is given, but I estimated a mass of 0.10685 ME based on differences between Study 1 and Study 2 masses for the six TRAPPIST planets. This gives Cheimon a density of 2.096 g/cm3 and a gravity of 0.249023 gees.

These results are incredibly important. Not only can the uncertainties caused by red dwarf activity be applied to many Exoplanet Explorers candidates, it gives more insight to the composition of these planets. All but two of the Trappist worlds - Theros and Irene - appear to be pure rock and iron planets, similar to Earth. Thallo and Auxo are likely iron-rich, while Eiar and Carphos seem close in composition to Earth. Theros and Irene have Mars-like densities, implying that about 15-20% of their total mass is water. That, or one or both of the planets have NO iron whatsoever and are 5-10% water by mass. Either way, I'm going to have to do a LOT of revamps of the TRAPPIST-1 system for Interstellar Adventure Revived.

Edited by ProtoJeb21
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48 minutes ago, Spaceception said:

Is Thallo bring iron rich good for potential habitability? Possibility of a strong magnetic field/tectonic plates (if tidal heating is significant enough), and many ores near the surface, probably a good place for intelligent life to develop. 

It would be a great mining planet and may be rich in life-supporting metals (molybdenum, selenium, etc). However, keep in mind that the error bars for all the planets' densities are ridiculously high. Damn noisy stars. 

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  • 1 month later...

The results by Barr et al indicate that most of the TRAPPIST-1 planets could be conductive to life, but in multiple different ways. Most are likely icy or ocean-covered worlds, while one could be a volcanic hellhole.

  • TRAPPIST-1b (Theros) has a mean density of 3.405 g/cm3, indicating a rock and iron composition with a thick water envelope. Tidal forces are even higher than Jupiter's moon Io, which would completely melt the majority of the silicate mantle. Theros is likely very volcanic, but all the volcanoes would be under a giant ocean, mixing water and various other compounds together. This could potentially lead to the development of life! However, Theros' proximity to its star, along with its rampant volcanism, leads the study authors to believe it is nearing a runaway greenhouse state. One day it will become a molten mess of a planet under a slowly evaporating, incredibly thick steam atmosphere.
  • TRAPPIST-1c (Auxo) is completely unlike any other planet in the system. It has a mean density of 7.642 g/cm3 and a ENORMOUS iron core, taking up over half the planet's radius. Auxo appears to be bone-dry and also very volcanic. Unlike Theros, there's no water envelope to suffocate volcanic activity, and tidal forces here are just as intense as on Io. The entire planet is likely covered in erupting volcanoes, spewing silicate lava over a scorched surface. These eruptions are predicted to be so intense, near-future technology could potentially detect them. Auxo is a grim reminder of what Theros (and maybe even Thallo) will become.
  • TRAPPIST-1d (Thallo) reigns as one of the best planets ever found to look for life. It's mean density of 3.96 g/cm3 (similar to Mars) allows for a thin surface-coating water envelope, with all the rest being a mix of silicates. Tidal forces here are just right to give Thallo Earth-like convection within its semi-molten mantle, potentially giving rise to a magnetic field. In addition, molten metals/materials with magnetic properties, such as Magnesium Oxide, could help build up a stronger magnetic field. In addition, undersea volcanoes are almost certainly present, giving rise to environments that could lead to the development of life. These volcanoes could push up to the surface and maybe form volcanic island chains. Thallo is also in less of a danger of becoming a Venus-like planet, as its low mass and tidally locked nature will likely allow for light-reflecting cloud cover and a thinner (but not too thin) atmosphere.
  • TRAPPIST-1e (Eiar) is one hell of a mystery. Its mass is by far the most uncertain of the system, which results in a variety of potential composition scenarios. The mean-density-composition, taking into account a density of ~1.713 g/cm3, suggests an interior of half rock, half water, potentially with an icy shell. With a more plausible, higher mass, Eiar could have a much more Earth-like composition, or may have a large iron core with tiny amounts of surface water. The somewhat more likely 50-50 composition suggests something similar to Europa, but even with a thin atmosphere (and help from tidal forces) can the icy crust completely melt, giving rise to a pure blue planet.
  • TRAPPIST-1f (Irene) finds itself in a similar position as Eiar. It has one of the most uncertain masses of all the TRAPPIST planets, but is more certain than its warmer neighbor. Irene is (no surprise) another watery world, almost identical in composition to Eiar...with a few exceptions. Irene's lower temperature and larger size, as well as its higher likelihood of being a volatile-rich planet, suggests it could be mostly ice-covered except for a moderately sized star-facing sea. However, I believe it could have accumulated a rather thick atmosphere of stuff like hydrogen and methane, melting the entire ice shell and making it something like a mini-mini-Neptune (aka an ocean planet with a pretty thick atmo). From here on out, stellar tidal forces are not enough to change the planet's interior.
  • TRAPPIST-1g (Carphos) has the best-constrained mass of the system, which made things easier for the study authors. The bad news? They couldn't identify the impacts of tidal forces on this planet...which might not matter a whole lot. Its mean density of 2.183 g/cm3 suggest a composition very similar to Eiar and Irene, but with a larger silicate core/mantle, maybe with some metals sprinkled in as well. An icy crust is predicted as well, but like Irene, Carphos could have a thick volatile-rich atmosphere that warms up portions of the surface. Remember, all the TRAPPIST-1 planets formed closer to the frost line before migrating inwards. Its not so far fetched to think that Irene and Carphos could have mini-mini-Neptunian atmospheres.
  • TRAPPIST-1h (Cheimon) is nothing more than a ball of ice. I'm not kidding. Its mean density of 1.299 g/cm3 suggests a composition of >80% ice, with a teensy little silicate core at the center. This makes Cheimon very similar to the icy moons of Europa and Enceladus and Ganymede, but whether or not it has a subsurface ocean remains to be seen.
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  • 3 weeks later...

Finally, newly updated planet sizes, temperatures, and incident fluxes! No mass values, though. A team managed to use twice as much Spitzer time as before to do the most accurate analysis of the TRAPPIST-1 system so far. Most of the planets are a bit bigger, and all are somehow cooler. Trappist-1d (Thallo) is now firmly within the conservative HZ with a stellar flux of 1.043, giving it an ESI of about 0.92. However, Trappist-1b (Theros) just got a lot worse. The team was able to analyze the planet’s atmosphere using a secondary eclipse of the planet, and found that it is a HUGE atmosphere. It has a scale height of over 50 km (Earth’s is 8 km), an atmospheric temperature in excess of 1,400 Kelvin, and appears to be rich in Carbon Dioxide with the possibility of H2 and methane. So Theros is definitely not a potentially habitable ocean world. Sorry @Spaceception

https://arxiv.org/pdf/1801.02554.pdf

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42 minutes ago, ProtoJeb21 said:

Finally, newly updated planet sizes, temperatures, and incident fluxes! No mass values, though. A team managed to use twice as much Spitzer time as before to do the most accurate analysis of the TRAPPIST-1 system so far. Most of the planets are a bit bigger, and all are somehow cooler. Trappist-1d (Thallo) is now firmly within the conservative HZ with a stellar flux of 1.043, giving it an ESI of about 0.92. However, Trappist-1b (Theros) just got a lot worse. The team was able to analyze the planet’s atmosphere using a secondary eclipse of the planet, and found that it is a HUGE atmosphere. It has a scale height of over 50 km (Earth’s is 8 km), an atmospheric temperature in excess of 1,400 Kelvin, and appears to be rich in Carbon Dioxide with the possibility of H2 and methane. So Theros is definitely not a potentially habitable ocean world. Sorry @Spaceception

https://arxiv.org/pdf/1801.02554.pdf

Oh dang... A worse hell than Venus then? Could this be a Volcanic world?

In a way, this could be a good thing, if this planet can hold such a thick atmosphere that close in, the others should be able to as well. Can't wait for JWST to give us data that changes a bunch of stuff again :D

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  • 4 weeks later...

We now know more about the TRAPPIST system than any other exoplanet system

https://www.jpl.nasa.gov/news/news.php?feature=7052

B is most likely a Venus like world, c is relatively earth like, d is an ocean world, density and gravity has been found for all of them.

Edited by insert_name
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3 hours ago, insert_name said:

We now know more about the TRAPPIST system than any other exoplanet system

https://www.jpl.nasa.gov/news/news.php?feature=7052

B is most likely a Venus like world, c is relatively earth like, d is an ocean world, density and gravity has been found for all of them.

You beat me to it! Either way, this discovery just made my day!

1482_PIA22093-NASAheader.jpg

796_TRAPPIST-1_sizes.jpeg

Edited by ProtoJeb21
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A little overview on what these planets are like:

  • TRAPPIST-1b and TRAPPIST-1c are, essentially, Venus on steroids. Planet b has an atmospheric pressure between 10 and 10,000 bars (9.87 to 9,869 atm), which is either enough to make walking around on this planet rather tough or be enough to crush you into a bubbling paste. The latter seems more likely, as its density and atmospheric characteristics suggest a Super-Venus like climate, in agreement with the >1,400 K atmospheric temperature reported by Delrez et al 2018. Trappist-1c is kinda-sorta-maybe-a-bit better, with a more rock-based composition and a less thick atmosphere. So instead of a global lava ocean, it probably has a terrain similar to Mustafar. Not much of an improvement, but...yeah it's terrible.
  • Thankfully, TRAPPIST-1d is far more promising and appears to resemble Scarif from Rogue One. It's actually about the same size as Scarif (0.784 Earth radii vs 0.710 Earth raii) but is just 0.297 Earth masses. Tiny! The surface gravity on TRAPPIST-1d is only 48% that of Earth's, about a third higher than that of Mars. It's the least dense planet of the system, with a density of 3.4 g/cm3 that implies it has a thin volatile layer. However, the atmosphere of TRAPPIST-1d (yes it has an atmosphere) is not hydrogen-rich, so that leaves only one option: a surface entirely covered in water. Maybe there could be some islands poking out, created by enormous undersea volcanoes powered by constant tidal heating. Depending on certain variables, TRAPPIST-1d is probably a planet teeming with aquatic life (although I'm not too sure if such life would produce any significant amounts of biosignatures). In addition, TRAPPIST-1d's global ocean and confirmed atmosphere indicate that scientists probably overestimated the threat of stellar activity on the habitability and atmospheres of the 7 planets.
  • Even more exciting than TRAPPIST-1d is TRAPPIST-1e. Unlike its inner three neighbors, this planet is purely rock and iron, with a larger core than Earth. It is very similar in size to Earth, with 91% the radius and 77% the mass. It surface gravity is 93% that of Earth, the second-highest of the system. Like planet d, TRAPPIST-1e has an atmosphere similar to that of the terrestrial planets in our solar system, but the exact composition and thickness will need to be determined by the JWST. Its atmosphere could be thicker than Earth's due to a more geologically active planet caused by tidal forces; however, the planet is likely too small and too far from the star to become a Venus analogue. TRAPPIST-1e appears to be the first Earth-analogue around any star that's been confirmed so far - it's just about the same radius, mass, gravity and density; it has a very similar temperature; it gets about 3/4 the sunlight as Earth; and it's likely to have a life-friendly atmosphere and surface water. If there's any life here, JWST should be able to detect it, which means that we could start of the 2020's with the discovery of the first example of extrasolar life.
  • TRAPPIST-1f and TRAPPIST-1g don't appear as promising as before. They're almost twin worlds, with about the same radius (1.046/1.148 R_Earth), mass (0.934/1.148 M_Earth), density (4.50 g/cm3/4.18 g/cm3) and surface gravity (0.85g/0.87g). Both planets are quite chilly, receiving between 40% and 20% the amount of energy that Earth gets from the Sun with equilibrium temperatures of 196 K and 178 K (which I calculated). Both planets are likely really, really fat Europa analogues, with icy shells surrounding a deep liquid water ocean above a rocky interior. Life could potentially evolve at the ocean basin around hydrothermal vents, but it depends on how large these vents are, as the seafloors of these planets are probably coated in Ice-VII and Ice-X. However, where TRAPPIST-1f has a hydrogen-free atmosphere, this isn't confirmed for TRAPPIST-1g. It's possible that it could have a strong greenhouse effect, melting the thick icy crust and turning it into a balmy ocean world. Or all the water would evaporate and turn TRAPPIST-1g into something like its fiery inner siblings. Let's hope that isn't the case.
  • For once, TRAPPIST-1h is given some interest and attention. Despite having a MUCH better artistic rendition than before, it's actually a relatively interesting planet. It's just a bit smaller than TRAPPIST-1d at 0.77 Earth radii, but is slightly more massive and has a high density (3.95 g/cm3) and surface gravity (0.554g). These parameters indicate two possibilities: an iron-free, Mars-like planet, or a mixed rock-ice planet. It could be a lot like an icy Mars, but probably with a thicker atmosphere. However, TRAPPIST-1h is too cold for liquid water, even with a thick atmosphere. It has an equilibrium temperature of a bone-chilling 155 K and gets only about 1/6th the stellar flux as Earth. All water will be frozen solid, and I'm not confident that there will be enough tidal forces to give it a subsurface ocean.
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17 minutes ago, Spaceception said:

@ProtoJeb21 So planet d is almost certainly covered in liquid water, and e may be a cooler analog to our blue marble?

That sounds amazing :D

I really hope that Spitzer can do infrared mapping of the planets, especially TRAPPIST-1d and e, to see which ones are habitable and how thick their atmospheres are. Janssen/55 Cancri e is a good example of how a planet can be characterized by simple heat mapping. Its maximum, minimum, dayside, and night side temperatures were found, and its atmosphere was revealed to be about 40% thicker than Earth’s with nitrogen, carbon monoxide, and/or oxygen. If Spitzer could spend some time mapping at least TRAPPIST-1b, I would be thrilled. I may be getting my wish, as the telescope is currently in another 500 hour study of the TRAPPIST-1 system, which will conclude in early March. Fingers crossed that it will be infrared mapping the planets.  

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  • 2 months later...

That's a bit odd. Of the seven planets only one managed to gather enough iron\nickel to create sizeable core? Does that indicate that protoplanetary disc of TRAPPIST-1 wasn't chemically homogenous?

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2 hours ago, Scotius said:

That's a bit odd. Of the seven planets only one managed to gather enough iron\nickel to create sizeable core? Does that indicate that protoplanetary disc of TRAPPIST-1 wasn't chemically homogenous?

Maybe TRAPPIST-1e was struck by another planet during its early formation, basting off its volatile (water/ice) layer that all the other TRAPPIST planets have. 

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On 2/7/2018 at 8:44 AM, ProtoJeb21 said:

I really hope that Spitzer can do infrared mapping of the planets, especially TRAPPIST-1d and e, to see which ones are habitable and how thick their atmospheres are. Janssen/55 Cancri e is a good example of how a planet can be characterized by simple heat mapping. Its maximum, minimum, dayside, and night side temperatures were found, and its atmosphere was revealed to be about 40% thicker than Earth’s with nitrogen, carbon monoxide, and/or oxygen. If Spitzer could spend some time mapping at least TRAPPIST-1b, I would be thrilled. I may be getting my wish, as the telescope is currently in another 500 hour study of the TRAPPIST-1 system, which will conclude in early March. Fingers crossed that it will be infrared mapping the planets.  

My fingers are going to hurt after this...

It would be so cool if we gave the TRAPPIST-1 planets names.

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2 hours ago, HansonKerman said:

My fingers are going to hurt after this...

It would be so cool if we gave the TRAPPIST-1 planets names.

I nicknamed the planets after seven of the Horae from Greek mythology: Theros, Auxo, Thallo, Eiar, Irene, Carphos, and Cheimon. However, I might rename them because of the February 2018 analysis. 

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They were talking about naming the planets. There are 7 of them. So it's convenient. then I considered naming the sun white after snow white. This is then funnier if it's not a white star because people will refer to it as the, "white star," when it's not a white star. If it is actually a white star then it is highly appropriate.

 

And having just looked it up it is, "an ultra cool red Dwarf star!" >< So, it's a fitting name with a bit of irony and humor attached. 8)

https://blog.oxforddictionaries.com/2015/12/21/names-of-the-seven-dwarfs/

https://en.wikipedia.org/wiki/Seven_Dwarfs#Names

https://en.wikipedia.org/wiki/Snow_White_and_the_Seven_Dwarfs_(1912_play)

Quote

That’s right. Unless you are an aficionado of the playwright Winthrop Ames (who wrote the play under the pseudonym Jessie Graham White)

So, name them:

Star: White (AKA snow white, aka Jessie Graham White, and pretend snow white got her hair died red.)

Planets: Doc, Grumpy, Happy, Sleepy, Bashful, Sneezy, and Dopey

Or

Planets: Blick, Flick, Glick, Plick, Snick, Whick, and Quee <- this one would go with the jessie graham white reference.

Or

Planets: Huckpack, Naseweis, Packe, Pick, Puck, Purzelbaum, and Rumpelbold

Or

Planets: Axelrod, Bartholomew, Cornelius, Dexter, Eustace, Ferdinand, and George <- It has george as a name. You can't loose there! ><

etc....

There even appears to be an anime with snow white with red hair. It's seems to be called snow white with the red hair... Go figure!

And if you want too add more humore you could say, "it's a trapist..." At which point you could go for hermaphradite and look for, "star,' fish names and references. Or just pretend it's a crossdressing snow white... Or that the guy name white(Jessie Graham White, Winthrop Ames) is playing the female role. Which would work as a playwright reference! 8)

Did he every play snow white in his plays? It would work on multiple levels then. lol

Edited by Arugela
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