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 Post subject: Re: TRAPPIST-1
PostPosted: Mon, 20-03-17, 8:27 GMT 
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stardust wrote:
t00fri wrote:
Great Stardust.

It is also evident that a lot more serious GUI-based simulation code in this field is ahead of the celestia.Sci dev team ;-) ...

Fridger


Oh no! I take it all back. :nono: :nono: :nono: :nono:


A huge program package like celestia.Sci will not be finished after a first release. ;-) My statement was merely to indicate that exo-planets and associated tools for their simulation will continue to play an important role in our further developments...

Specifically, what I plan for celestia.Sci is to extend the eclipse finder to a transit finder for the TRAPPIST-1 system (!!) and to simulate the photometry of planetary transits of the TRAPPIST-1 star via a Qt plotting package that we use already for our Gravitational MicroLensing displays...

Fridger

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 Post subject: Re: TRAPPIST-1
PostPosted: Mon, 20-03-17, 14:33 GMT 
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t00fri wrote:
stardust wrote:
t00fri wrote:
Great Stardust.

It is also evident that a lot more serious GUI-based simulation code in this field is ahead of the celestia.Sci dev team ;-) ...

Fridger


Oh no! I take it all back. :nono: :nono: :nono: :nono:


A huge program package like celestia.Sci will not be finished after a first release. ;-) My statement was merely to indicate that exo-planets and associated tools for their simulation will continue to play an important role in our further developments...

Specifically, what I plan for celestia.Sci is to extend the eclipse finder to a transit finder for the TRAPPIST-1 system (!!) and to simulate the photometry of planetary transits of the TRAPPIST-1 star via a Qt plotting package that we use already for our Gravitational MicroLensing displays...

Fridger


Thanks for the explanation. I will continue to patiently wait for the release of celestia.Sci. :°

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 Post subject: Re: TRAPPIST-1
PostPosted: Mon, 20-03-17, 17:00 GMT 
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Posts: 53
celestia.exe 1.6.1 TRAPPIST-1

M8 = 2640K

B => 343 K (Albedo 0.07 = 400 K)
C => 293 K (Albedo 0.07 = 342 K)
D => 247 K (Albedo 0.07 = 288 K)
E => 215 K (Albedo 0.07 = 251 K)
F => 188 K (Albedo 0.07 = 219 K)
G => 170 K (Albedo 0.07 = 199 K)
H => 149 K (Albedo 0.15 = 170 K) <= ;)

https://fr.wikipedia.org/wiki/TRAPPIST-1

B => 400.1 K
C => 341.9 K
D => 288 K
E => 251.3 K
F => 219 K
G => 198.6 K
H => 170 K

update 03/22/2017

:p


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 Post subject: Re: TRAPPIST-1
PostPosted: Wed, 22-03-17, 3:20 GMT 
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:oops: oups

"Albedo 0.07" => B C D E F G

"Albedo 0.15" => H

^^


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 Post subject: Re: TRAPPIST-1
PostPosted: Fri, 24-03-17, 16:15 GMT 
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https://arxiv.org/abs/1703.06924

Formation of TRAPPIST-1 and other compact systems

the H2O iceline


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 Post subject: Re: TRAPPIST-1
PostPosted: Mon, 10-04-17, 6:51 GMT 
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https://arxiv.org/abs/1704.02261

Plausible Compositions of the Seven TRAPPIST-1 Planets Using Long-term Dynamical Simulations

TRAPPIST-1 is a nearby ultra-cool dwarf that is host to a remarkable planetary system consisting of seven transiting planets.

Here we perform many thousands of N-body dynamical simulations with planet properties perturbed from the observed values and identify those that are stable for millions of years. This allows us to identify self-consistent orbital solutions that can be used in future studies. From our range of dynamical masses, we find that most of the planets are consistent with an Earth-like composition, where TRAPPIST-1f is likely to have a volatile-rich envelope.


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 Post subject: Re: TRAPPIST-1
PostPosted: Mon, 17-04-17, 17:06 GMT 
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planet B

1.51087081 day => P
0.1111 AU => a
0.08015 M_Sun => GM

http://orbitsimulator.com/formulas/sma.html

0.01111021993475113 AU

;)


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 Post subject: Re: TRAPPIST-1
PostPosted: Thu, 20-04-17, 17:05 GMT 
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That paper actually raises a point to bear in mind when figuring out how to render these planets.

Quote:
Using the H2O-REOS equation of state for water (French et al. 2009; Nettelmann et al. 2010) and thermal evolution models of Lopez & Fortney (2014), we find that even at an age of 8 Gyr the temperature at the bottom of such an envelope will be ≳1400K and the pressure will reach ≈130 kbar. For comparison, the pressure in the deepest parts of Earth’s oceans is ≈1 kbar. Moreover, these calculations don’t include the possibility of significant tidal heating from planet-planet interactions, which could raise the interior temperature even higher. At such a high pressure and temperature, water will be far beyond the triple point and far too hot for high pressure ices like ice VII and X. Instead, it will exist as a high pressure molecular fluid, much like the deep interiors of Neptune and Uranus (Fortney et al. 2011; Nettelmann et al. 2011). Therefore, liquid water will likely only exist in clouds near the top of TRAPPIST-1f’s atmosphere and our results suggest that it is no more likely to be habitable than any other gas or ice-giant with water clouds in its atmosphere.


This makes me wonder if it is worth implementing special handling for planets between the 100% rock and 100% ice compositions, or just to throw everything larger than the maximum rocky planet size into the gas giant category: this suggests that only very small ice planets (smaller than most known exoplanets) will be ocean worlds.

Furthermore, the most recent update (Wang et al., 2017) seems to have substantially decreased the masses for the planets, with only planets c and d having their estimates within the rocky planet region. Given that the planets seem to be in near-resonances and therefore likely migrated inwards from colder parts of the system, ice-rich compositions don't seem too implausible.


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 Post subject: Re: TRAPPIST-1
PostPosted: Fri, 05-05-17, 11:18 GMT 
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https://arxiv.org/abs/1705.00625

We illustrate this bias using the exoplanet TRAPPIST-1b

400K to 800K


Star, continuum => 2760K
Star, line region => 1700K


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