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Exoplanet Discoveries, discussion of the latest finds
Guest_PhilCo126_*
post Apr 21 2009, 11:10 AM
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Well-known exoplanet researcher Dr Michel Mayor ( discoverer of Peg 51b with Dr Didier Queloz in 1995 ) today announced the discovery of the lightest exoplanet found so far. The planet, “e”, in the famous system Gliese 581, is only about twice the mass of our Earth. The team also refined the orbit of the planet Gliese 581 d, first discovered in 2007, placing it well within the habitable zone, where liquid water oceans could exist:
http://www.eso.org/public/outreach/press-r...9/pr-15-09.html

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hendric
post Feb 22 2017, 06:16 PM
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https://www.nasa.gov/press-release/nasa-tel...-planets-around

https://exoplanets.nasa.gov/trappist1/


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Space Enthusiast Richard Hendricks
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"The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke
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HSchirmer
post Feb 22 2017, 06:57 PM
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QUOTE (hendric @ Feb 22 2017, 06:16 PM) *


http://www.trappist.one/
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JRehling
post Feb 22 2017, 08:06 PM
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This is quite an interesting and – IMO – surprising discovery for the sheer number of planets packed so tightly together. Six of the planets have orbital periods between 1.51 and 12.35 days. Not surprisingly, there are small-integer ratios galore between orbital periods. In terms of the shortest period, the next four are 8:5, 8:3, 4:1, and 6:1.

In terms of bolometric luminosity, the second, third, and fourth ones get about the same thermal input as Venus, Earth, and Mars. There's no doubt that whatever one considers to be earthlike context in terms of that alone, at least one of these planets has it.

And here's one of the interesting consequences: There are about 500 red dwarfs closer than this system. The probability of a transit for a single planet in the "habitable zone" of such stars is about 2.5%, which would mean 12.5 such systems. But if there are multiple planets per system, then the number of planets we can see transiting will be higher than ~12.5, perhaps double that. And that'll increase the bounty when the time comes that we can do serious follow-up science by examining spectra.

A decade or so from now, we may have spectra for something like 20-50 sub-Neptune-sized planets in the HZ of red dwarfs. That's a nice future set of results to look forward to.
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ngunn
post Feb 22 2017, 09:03 PM
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QUOTE (JRehling @ Feb 22 2017, 08:06 PM) *
Not surprisingly, there are small-integer ratios galore between orbital periods.


And, if the Jovian system is anything to go by, these resonances will be evolving over time with each planet experiencing different episodes of orbital forcing, eccentricity change and tidal heating. So once the orbital/thermal history of the Galilean moons has been definitively settled the dynamicists will then have this diabolically complex and even more crowded planetary system to chew over.

Another curiosity is that the system lies within one degree of our ecliptic plane. Does this mean that seen from there our Sun would also exhibit planetary transits?
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Posts in this topic
- PhilCo126   Exoplanet Discoveries   Apr 21 2009, 11:10 AM
- - belleraphon1   32 New Exoplanets Found - 10/19/09 ESO release ...   Oct 19 2009, 01:32 PM
- - Julius   How can they be so sure that the super earths dete...   Oct 20 2009, 11:10 AM
|- - qraal   QUOTE (Julius @ Oct 20 2009, 10:10 PM) Ho...   Oct 20 2009, 11:27 AM
|- - Greg Hullender   There's a branch of mathematics called "F...   Oct 20 2009, 07:47 PM
|- - tfisher   QUOTE (Greg Hullender @ Oct 20 2009, 02:4...   Oct 22 2009, 12:30 AM
|- - Greg Hullender   QUOTE (tfisher @ Oct 21 2009, 05:30 PM) I...   Oct 22 2009, 02:26 AM
|- - Hungry4info   QUOTE (Greg Hullender @ Oct 21 2009, 08:2...   Oct 22 2009, 12:33 PM
|- - Greg Hullender   QUOTE (Hungry4info @ Oct 22 2009, 04:33 A...   Oct 22 2009, 05:31 PM
- - imipak   'Spherical cow' now has it's very own ...   Oct 23 2009, 06:47 PM
- - PhilCo126   Team of Astronomers using Japanese Subaru Telescop...   Dec 5 2009, 05:47 PM
- - Hungry4info   I'm quite unsure as to why this is being made ...   Dec 6 2009, 04:00 AM
|- - centsworth_II   QUOTE (Hungry4info @ Dec 5 2009, 11:00 PM...   Dec 6 2009, 07:15 AM
- - ngunn   On a different topic, I've not noticed discuss...   Dec 6 2009, 11:57 AM
- - Hungry4info   QUOTE ("centsworth_II")Isn't this ju...   Dec 6 2009, 02:26 PM
|- - ngunn   Yes I noticed the range of hypotheses offered, but...   Dec 6 2009, 04:57 PM
- - Hungry4info   Of course it's more exciting, but only in the ...   Dec 6 2009, 05:07 PM
|- - ngunn   QUOTE (Hungry4info @ Dec 6 2009, 05:07 PM...   Dec 6 2009, 09:28 PM
- - scalbers   I guess we can mention GJ1214b and the MEarth proj...   Jan 1 2010, 06:06 PM
- - PhilCo126   Keck telescopes on Mauna Kea - Hawaii discovered 2...   Jan 9 2010, 09:59 AM
- - Mongo   I will charitably assume that the reporters left o...   Jan 9 2010, 02:57 PM
- - belleraphon1   Agreed Mongo... Go to Extrsolar Planets Encyclope...   Jan 9 2010, 08:06 PM
- - ngunn   There is nothing like new data for shaking things ...   Apr 14 2010, 10:59 AM
- - Ron Hobbs   The VLT has taken pictures of a planet orbiting be...   Jun 11 2010, 06:40 PM
- - remcook   Doing observations from the ground can have its ad...   Jun 24 2010, 08:06 AM
- - Drkskywxlt   Confirmation of the first directly imaged planet a...   Jun 30 2010, 05:42 PM
|- - ustrax   It's extragalactastic! http://www.eso.org...   Nov 18 2010, 07:55 PM
|- - ustrax   500! and 2... Wow! And to think that we j...   Nov 19 2010, 11:09 PM
- - remcook   Well, finally that mysterious DPS presentation got...   Dec 2 2010, 09:14 AM
- - ngunn   Free floating planets found by microlensing: http:...   May 19 2011, 04:14 PM
- - TheAnt   Some years ago we were given the impression that q...   Jun 19 2016, 09:49 AM
- - Explorer1   A Proxima Centauri planet!? http://phys.org...   Aug 13 2016, 06:58 AM
- - Gerald   Seems, they found a hint to a small deviation of P...   Aug 13 2016, 07:46 AM
- - HSchirmer   Just noticed that Der Spiegel and other online sou...   Aug 14 2016, 01:30 AM
|- - JRehling   Google searches limited to the last week show seve...   Aug 14 2016, 02:32 AM
- - nprev   MOD MODE: Merged topic created for this alleged Pr...   Aug 14 2016, 07:41 AM
|- - JRehling   This is indeed a good time to invoke Sagan's L...   Aug 14 2016, 03:01 PM
- - Explorer1   Presumably they wouldn't have published the ar...   Aug 14 2016, 04:18 PM
- - Gerald   Pale Red Dot has submitted a paper for peer review...   Aug 14 2016, 11:12 PM
- - nprev   Thanks, Gerald. That's the kind of clarifying ...   Aug 14 2016, 11:35 PM
- - alphasam   I'll just leave this here From BBC The Sky a...   Aug 18 2016, 07:09 PM
|- - JRehling   Der Spiegel has published a new article that almos...   Aug 19 2016, 06:23 PM
- - alphasam   There will be a press conference at ESO headquarte...   Aug 22 2016, 02:14 PM
- - TheAnt   Hmm, if Der Spiegel is to believed, it is now clai...   Aug 23 2016, 06:26 PM
- - Gerald   ESO on twitter: QUOTE Dear friends we will be maki...   Aug 24 2016, 11:46 AM
- - alphasam   Yeah, there is a conference with the press going o...   Aug 24 2016, 11:52 AM
- - DEChengst   ESOcast 87: Pale Red Dot Results: https://www.eso...   Aug 24 2016, 05:04 PM
- - TheAnt   Here we got the full facts, a 'year' lasti...   Aug 24 2016, 05:15 PM
- - Gladstoner   FYI, Centauri Dreams is a good resource for exopla...   Aug 24 2016, 07:49 PM
|- - JRehling   This work contains, also, an interesting hint of t...   Aug 25 2016, 12:59 AM
- - Mongo   Exploring plausible formation scenarios for the pl...   Aug 25 2016, 01:46 AM
|- - JRehling   An important result, discussed in more detail in t...   Aug 25 2016, 04:08 AM
- - Mongo   Tutorial models of the climate and habitability of...   Aug 26 2016, 12:26 AM
- - Mongo   Prospects for Characterizing the Atmosphere of Pro...   Aug 29 2016, 01:33 AM
|- - Holder of the Two Leashes   QUOTE (Mongo @ Aug 28 2016, 07:33 PM) ......   Aug 29 2016, 05:53 PM
|- - JRehling   I think JWST will be able to study planets in the ...   Aug 30 2016, 06:34 PM
- - katodomo   As an overall strategy, JWST is more of an interme...   Aug 31 2016, 06:21 PM
- - ZLD   Not getting my hopes up for TMT anymore. While onl...   Sep 1 2016, 02:18 AM
- - Mongo   This one is interesting, it considers what can be ...   Sep 13 2016, 01:10 AM
- - Explorer1   Press conference tomorrow on a new discovery, expe...   Feb 21 2017, 08:03 PM
- - nprev   Reminder to all: We do not discuss embargoed infor...   Feb 22 2017, 01:50 AM
- - hendric   https://www.nasa.gov/press-release/nasa-tel...-pla...   Feb 22 2017, 06:16 PM
|- - HSchirmer   QUOTE (hendric @ Feb 22 2017, 06:16 PM) h...   Feb 22 2017, 06:57 PM
|- - JRehling   This is quite an interesting and – IMO – surprisin...   Feb 22 2017, 08:06 PM
|- - ngunn   QUOTE (JRehling @ Feb 22 2017, 08:06 PM) ...   Feb 22 2017, 09:03 PM
|- - JRehling   QUOTE (ngunn @ Feb 22 2017, 02:03 PM) Ano...   Feb 22 2017, 09:36 PM
|- - ngunn   QUOTE (JRehling @ Feb 22 2017, 09:36 PM) ...   Feb 22 2017, 10:52 PM
||- - JRehling   QUOTE (ngunn @ Feb 22 2017, 03:52 PM) So ...   Feb 23 2017, 05:41 AM
||- - TheAnt   QUOTE (JRehling @ Feb 23 2017, 06:41 AM) ...   Feb 23 2017, 12:41 PM
||- - hendric   QUOTE (JRehling @ Feb 22 2017, 11:41 PM) ...   Feb 23 2017, 05:24 PM
||- - JRehling   The big reason why it is much easier to determine ...   Feb 23 2017, 06:15 PM
|- - fredk   QUOTE (JRehling @ Feb 22 2017, 10:36 PM) ...   Feb 23 2017, 07:23 PM
- - nprev   ADMIN NOTE: All TRAPPIST-1 posts have been moved h...   Feb 23 2017, 05:54 AM
- - ngunn   When will we know we have fathomed the'norms o...   Feb 23 2017, 07:38 PM
- - hendric   If I am reading the Simbad entry correct for Trapp...   Feb 23 2017, 08:27 PM
- - fredk   Looks good, Hendric. (But that's 23' from...   Feb 23 2017, 09:33 PM
- - ngunn   Brilliant stuff guys, thanks for taking an interes...   Feb 23 2017, 11:33 PM
- - Explorer1   QUOTE It's possible to resolve this, eventuall...   Feb 24 2017, 12:33 AM
|- - JRehling   QUOTE (Explorer1 @ Feb 23 2017, 05:33 PM)...   Feb 24 2017, 02:38 AM
|- - TheAnt   QUOTE (JRehling @ Feb 24 2017, 03:38 AM) ...   Feb 24 2017, 08:17 AM
|- - JRehling   QUOTE (TheAnt @ Feb 24 2017, 01:17 AM) Ye...   Feb 25 2017, 10:45 PM
|- - Julius   [quote name='JRehling' date='Feb 25 20...   Feb 26 2017, 08:10 PM
|- - JRehling   I can only say "Suppose that tidal locking me...   Feb 26 2017, 10:23 PM
- - hendric   In a related Nova episode on the Origami Revolutio...   Feb 24 2017, 05:33 PM
- - scalbers   For visually resolving I remain a fan of the old P...   Feb 25 2017, 12:47 AM
- - ZLD   QUOTE (scalbers @ Feb 24 2017, 06:47 PM) ...   Feb 26 2017, 03:00 PM
- - Hungry4info   The default assumption is the slower rotation peri...   Feb 26 2017, 08:44 PM
- - fredk   Well, for these new planets their orbital periods ...   Feb 26 2017, 09:30 PM
- - ngunn   I also wondered the same thing, and noted that all...   Feb 26 2017, 10:13 PM
- - Explorer1   If 59 day rotation is fast enough to get a magneti...   Feb 27 2017, 05:17 AM
- - Mongo   Towards Detection of Exoplanetary Rings Via Transi...   Feb 28 2017, 08:21 PM
- - Explorer1   Very cool; reminds me of J1407 ( https://en.wikipe...   Mar 1 2017, 12:17 AM
- - marsbug   Somehow I'd mised that - a ring system with th...   Mar 8 2017, 02:47 AM
- - TheAnt   Of minor importance perhaps, yet more observations...   Mar 19 2017, 01:29 PM
- - Mongo   A revolution is brewing: observations of TRAPPIST-...   Apr 3 2017, 01:25 AM
|- - JRehling   QUOTE (Mongo @ Apr 2 2017, 06:25 PM) Plea...   Apr 3 2017, 01:51 AM
- - Ron Hobbs   And did you notice this was published in the ...   Apr 3 2017, 02:50 AM
|- - JRehling   After that April Fools joke… here's an actual ...   Apr 13 2017, 05:47 AM
- - tanjent   " it’s roughly Earth-sized, and has slightly ...   Apr 13 2017, 02:55 PM
- - scalbers   I wonder what the limits of this technique are wit...   Apr 13 2017, 04:26 PM
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