Author Topic: NASA's Trappist-1 Announcement - Feb 22, 2017  (Read 55396 times)

Offline as58

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The discovery paper (supplement) discusses the long-term stability of the system and it is mentioned that it's very hard to keep even the known system stable.

Offline gosnold

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The discovery paper (supplement) discusses the long-term stability of the system and it is mentioned that it's very hard to keep even the known system stable.

Isn't that true even for our solar system? I recall reading the accuracy of our orbital predication degrades past a couple hundred million years.

Offline as58

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The discovery paper (supplement) discusses the long-term stability of the system and it is mentioned that it's very hard to keep even the known system stable.

Isn't that true even for our solar system? I recall reading the accuracy of our orbital predication degrades past a couple hundred million years.

Sure, to some extent. But in case of TRAPPIST-1 most simulations apparently lead to disruption of the system on a time scale of a million years or less.

Offline Star One

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The discovery paper (supplement) discusses the long-term stability of the system and it is mentioned that it's very hard to keep even the known system stable.

Isn't that true even for our solar system? I recall reading the accuracy of our orbital predication degrades past a couple hundred million years.

Sure, to some extent. But in case of TRAPPIST-1 most simulations apparently lead to disruption of the system on a time scale of a million years or less.

That's not quite correct as if you use a different statistical method you get a differing more positive result and either way there's a great deal of uncertainty in all methods used.

http://astronomy.stackexchange.com/questions/20160/are-the-trappist-1-planets-in-stable-orbits

As it says here and I've read elsewhere the planets fall into near-integer resonances.
« Last Edit: 02/24/2017 06:58 pm by Star One »

Offline Star One

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Quote
Judy Schmidt‏ @SpaceGeck

I've got an accurate little TRAPPIST-1 system set up in Blender. This is 1 year of looking at the star from planet e.

Animation on link below.

https://mobile.twitter.com/SpaceGeck/status/835552362534219777

Offline Star One

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A Nearby Galactic Empire?

Quote
Meanwhile, we can do at least one experiment: Examine this system for radio signals that would indicate the presence of intelligence.  And indeed, the SETI Institute used its Allen Telescope Array last year to observe the environs of Trappist 1, scanning through ten billion radio channels in search of signals.  No transmissions were detected, although new observations are in the offing. 

How sensitive was this search?  Assuming that the putative inhabitants of this solar system can use a transmitting antenna as large as the 500 meter FAST radio telescope in China to beam their messages our way, then the Allen Array could have found a signal if the aliens use a transmitter with 100 kilowatts of power or more.  This is only about ten times as energetic as the radar down at your local airport.

And whether or not Trappist 1 has inhabitants, its discovery has underlined the growing conviction that the universe is replete with real estate on which biology could both arise and flourish.  If you still think the rest of the universe is sterile, you are surely singular, and probably wrong.

http://www.seti.org/seti-institute/Nearby-Galactic-Empire

The (Potentially) Habitable Worlds of TRAPPIST-1

Quote
When the news about the seven planets of TRAPPIST-1 broke, I immediately wondered what Andrew LePage’s take on habitability would be. A physicist and writer with numerous online essays and a host of articles in magazines like Scientific American and Sky & Telescope, LePage is also a specialist in the processing and analysis of remote sensing data. He has put this background in data analytics to frequent use in his highly regarded ‘habitable planet reality checks,’ which can be found on his Drew ex Machina site. Having run a thorough analysis of the TRAPPIST-1 situation the other day, Drew now gives us the gist of his findings, which move at least several of the TRAPPIST-1 planets into a potentially interesting category indeed.

http://www.centauri-dreams.org/?p=37225
« Last Edit: 02/27/2017 07:14 pm by Star One »

Offline Star One

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Offline Star One

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Public tries to name 7 new planets after Nasa discovery- with chaotic results

http://www.telegraph.co.uk/news/2017/03/02/nasa-asks-public-help-name-7-new-plants-chaotic-results/

Offline CuddlyRocket

Public tries to name 7 new planets after Nasa discovery- with chaotic results

http://www.telegraph.co.uk/news/2017/03/02/nasa-asks-public-help-name-7-new-plants-chaotic-results/

One of the reasons the IAU was founded was to stop this kind of chaos when it comes to the naming of celestial bodies (the arguments over the naming of Neptune were quite vicious). But in order to prevent other people giving exoplanets names, the IAU has to get round to naming them itself! I know Eric Mamajek, who is a member of the Executive Committee Working Group on the Public Naming of Planets and Planetary Satellites, is keen that the IAU runs another round of its successful NameExoWorlds process, though apparently there's opposition (professional astronomers can get a bit snobby at times IMO).

Offline Star One

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Public tries to name 7 new planets after Nasa discovery- with chaotic results

http://www.telegraph.co.uk/news/2017/03/02/nasa-asks-public-help-name-7-new-plants-chaotic-results/

One of the reasons the IAU was founded was to stop this kind of chaos when it comes to the naming of celestial bodies (the arguments over the naming of Neptune were quite vicious). But in order to prevent other people giving exoplanets names, the IAU has to get round to naming them itself! I know Eric Mamajek, who is a member of the Executive Committee Working Group on the Public Naming of Planets and Planetary Satellites, is keen that the IAU runs another round of its successful NameExoWorlds process, though apparently there's opposition (professional astronomers can get a bit snobby at times IMO).

NASA I suppose could have pointed out it was actually up to the IAU to name them, but then that would have taken all the fun out of it.

Offline jebbo

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The raw K2 light curve will be available for download from MAST at 9am PST on Tuesday.

Edit: details here http://archive.stsci.edu/k2/trappist1/index.html

-- Tony
« Last Edit: 03/04/2017 07:58 pm by jebbo »

Offline jebbo

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The K2 light curve is available and, as expect, it seems the period of "h" has been pinned down. The linked tweet shows the folded long cadence data:

https://twitter.com/AgolEric/status/839549713313476608

They are being coy over the period though ...

Also, Trappist-1 flares frequently:

https://github.com/jradavenport/trappist/blob/master/explore.ipynb
https://twitter.com/johngizis/status/839721186133180417

I expect the next few days will see better analysis and things like TTV O-C plots.

--- Tony
« Last Edit: 03/09/2017 10:25 am by jebbo »

Offline Star One

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NASA gives out data about star with 7 Earth-sized planets for free

http://mashable.com/2017/03/08/trappist-1-data-nasa-kepler-space-telescope/

Think it's a bit sad when it sounds a bit surprising to people that scientific data should actually be distributed freely.

This is worth a look on as well.

https://www.reddit.com/r/space/comments/5yanmj/oc_nasa_just_released_keplers_data_on_trappist1/
« Last Edit: 03/09/2017 09:52 am by Star One »

Offline as58

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A period of ~23 days for TRAPPIST-1h has been mentioned, which puts is close to the middle of the error bars announced earlier.

The star does seem to flare a lot.

Offline jebbo

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Yes, my tools suggest about ~23.4 but I'm hesitant as I lost my old KepCurve source code and the current re-write is very primitive still (to say the least!).

FWIW, my data was backed up perfectly; turns out my source only had 1 backup and the backup copy managed to copy a totally corrupt archive.  Needless to say, this time, I'm paying more attention :-) [ and will put the source on github when more useable ]

Edit: thinking about it, 23.4 is not favoured but I have 3 periods to check :-)

--- Tony
« Last Edit: 03/09/2017 02:25 pm by jebbo »

Offline jebbo

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A new Trappist-1 paper will be on arxiv.org tomorrow, with details of "h" and I suspect updated periods for the other planets.

It may also include a corrected stellar rotation period (a paper last year in Nature has this as ~1.4 days; however it is clear from the raw light curve that is it ~3.27d).

https://twitter.com/ethan_kruse/status/841092095448305665

--- Tony

Offline Star One

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Re: NASA's Trappist-1 Announcement - Feb 22, 2017
« Reply #116 on: 03/13/2017 03:17 pm »
Seems it's proving a little tricky trying to figure out how old TRAPPIST-1 is.

http://www.sciencealert.com/astronomers-question-if-trappist-1-s-planets-are-habitable-afterall

Offline Ben the Space Brit

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Re: NASA's Trappist-1 Announcement - Feb 22, 2017
« Reply #117 on: 03/13/2017 03:39 pm »
That's class-M dwarves for you: Once they hit main sequence, there's really no way to easily tell the difference between 100 million or 10 billion years old!
"Oops! I left the silly thing in reverse!" - Duck Dodgers

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The Space Shuttle Program - 1981-2011

The time for words has passed; The time has come to put up or shut up!
DON'T PROPAGANDISE, FLY!!!

Offline Star One

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Re: NASA's Trappist-1 Announcement - Feb 22, 2017
« Reply #118 on: 03/13/2017 03:53 pm »
That's class-M dwarves for you: Once they hit main sequence, there's really no way to easily tell the difference between 100 million or 10 billion years old!

From my limited understanding of that article it's the radiation output that's proving contradictory ageing wise.

Offline jebbo

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Re: NASA's Trappist-1 Announcement - Feb 22, 2017
« Reply #119 on: 03/13/2017 04:27 pm »
That's class-M dwarves for you: Once they hit main sequence, there's really no way to easily tell the difference between 100 million or 10 billion years old!

From my limited understanding of that article it's the radiation output that's proving contradictory ageing wise.

It's worse than that. I think that article references the 1.4 day stellar rotation period from Nature. But the actual rotation period is more like 3.3 days.

So that is contradictory as well, indicating a much older star (>= ~1bn). However,  gyrochronology is poorly constrained for M dwarfs.

--- Tony

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