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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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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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 Post subject: Re: TRAPPIST-1
PostPosted: Sun, 02-07-17, 19:43 GMT 
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I had a little time to refine some of my TRAPPIST-1 textures:

TRAPPIST-1d:

Attachment:
TRAPPIST-1d.png
TRAPPIST-1d.png [ 1.37 MiB | Viewed 362 times ]


TRAPPIST-1e:

Attachment:
TRAPPIST-1e.png
TRAPPIST-1e.png [ 1.7 MiB | Viewed 362 times ]


TRAPPIST-1f:

Attachment:
TRAPPIST-1f.png
TRAPPIST-1f.png [ 1.68 MiB | Viewed 362 times ]


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 Post subject: Re: TRAPPIST-1
PostPosted: Sun, 02-07-17, 19:49 GMT 
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Changes: TRAPPIST-1d must have ice on the dark side, TRAPPIST-1e must have a more fragmented ice cover, so I changed the textures. TRAPPIST-1f needed some editing because of ugly layer effects.


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 Post subject: Re: TRAPPIST-1
PostPosted: Mon, 03-07-17, 2:40 GMT 
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without more information a 256 x 128 texture is about it

NOW i do like to make " WHAT IF'S " however there are 4096x2048 at the max

However there is no real GREAT way to "create textures"

i can start from a 32x16 sim output of a " maybe"

then augment from there ... and statistically fill in data

but that is JUST A GUESS !!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!


SO

the big question is -----
"are my guesses good ? or very good ?
??????????????????????????????????????????????????

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 Post subject: Re: TRAPPIST-1
PostPosted: Mon, 03-07-17, 13:32 GMT 
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sjohn wrote:
I had a little time to refine some of my TRAPPIST-1 textures:

Looking nice. Are these textures 8k or even bigger?

I would very much like to start from a listing of established surface properties for each TRAPPIST-1 planet. These properties should then be exclusively used for making the planetary textures. Then, using the familiar key shortcut or via some new code, we might blend in another texture level / layer, adding properties that will / can be measured in the (near?) future. One then could switch between such alternative surface textures to display how remaining uncertainties could still affect the planets' appearances.

Making instead impressive and very detailed (fictional) textures of the TRAPPIST-1 planets is a lot of fun (I know this from my own respective activities ;-) ). Instead, the sketched, more scientific approach would provide a reliable and thus valuable / educational visual reference about the system.

Fridger

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 Post subject: Re: TRAPPIST-1
PostPosted: Mon, 03-07-17, 18:55 GMT 
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Quote:
Looking nice. Are these textures 8k or even bigger?


Thanks, the cloud texture is 32k, the surface, specular and bump textures are 8k.

Quote:
Instead, the sketched, more scientific approach would provide a reliable and thus valuable / educational visual reference about the system.


I would be very grateful to see more facts about these planets. I read some studies on arXiv, but it would be nice to have some scientific help...(like what are the "real" effects of atmospheric changes etc.).

I do think realism is very important. But a sketch is not fully realistic, it is only abstract and logical.

So it is very good to have a more scientific approach, but I think you should also consider psychological realism.

If a scientifically realistic and accurate sketch gets layers of psychological realism then scientists and non scientists alike can equally enjoy the result...in my opinion...


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 Post subject: Re: TRAPPIST-1
PostPosted: Mon, 03-07-17, 20:05 GMT 
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Celestia supports OverlayTextures used as "limits of knowledge" in addition to multiple AltSurface declarations. Hopefully CelestiaSci does, too. Either of those could be used to make simultaneously available both the best scientific and the best imaginative surface feature maps.

FWIW, I've stumbled across several problems in Celestia v1.6.1 when trying to use VirtualTextures as OverlayTextures, including black regions and/or distorted tiles when some tiles are omitted from some of the VT levels. It'd be nice to know if those kinds of bugs have been fixed in CelestiaSci.

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