| 55 Cancri e -- Transits detected!! | |
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+10AVBursch atomic7732 Borislav Stalker tommi59 lodp Edasich Lazarus exoplanet Sirius_Alpha 14 posters |
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exoplanet Planetesimal
Number of posts : 124 Location : here Registration date : 2008-06-16
| Subject: Re: 55 Cancri e -- Transits detected!! 7th June 2011, 6:10 am | |
| I missed that link. Thanks ! | |
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Lazarus dF star
Number of posts : 3337 Registration date : 2008-06-12
| Subject: Re: 55 Cancri e -- Transits detected!! 8th June 2011, 1:26 am | |
| One thing I have to wonder is if 55 Cnc e is actually volatile-rich. Certainly it would appear to be an unfavourable environment due to stellar irradiation. Maybe it is a carbon planet. This paper suggests that 55 Cancri should have produced planets more enriched in carbon than our own, particularly in the inner regions: - Quote :
- The location of the C zone also implies that the four inner known giant planets of the 55Cnc system (located at 0.038 AU, 0.115 AU, 0.24 AU, and 0.781 AU) should contain significant amounts of C, both in their solid cores and in their atmospheres if they formed at or in close proximity to their current orbital locations and also depending on the exact time of their formation.
Furthermore carbon planets seem to have the right kind of radii, e.g. from this paper: - Quote :
- While the zero-pressure density of graphite (2.25 g/cm3) is almost twice that of water ice VII (1.46 g/cm3), a graphite planet with an Fe core has a similar average density to a water planet with an iron core and silicate mantle.
So I really have to wonder if we might be looking at a carbon-rich planet. Would certainly provide an interesting validation of the modelled dependence between stellar abundances and terrestrial planet composition. | |
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Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Re: 55 Cancri e -- Transits detected!! 8th June 2011, 3:47 am | |
| Very interesting! I really like that hypothesis. Perhaps this could be tested by checking for an exosphere around the planet like at Mercury. _________________ Caps Lock: Cruise control for 'Cool'!
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tommi59 Jovian
Number of posts : 596 Age : 46 Location : Baile Atha Cliath Registration date : 2010-07-31
| Subject: Re: 55 Cancri e -- Transits detected!! 8th June 2011, 4:38 am | |
| Really likely I doubted this planet could have any light elements and explanation of lazarus with carbon planets seems to be great I am curious how many carbon planet exist really?Hmm? | |
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Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Re: 55 Cancri e -- Transits detected!! 26th September 2011, 4:42 pm | |
| _________________ Caps Lock: Cruise control for 'Cool'!
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Lazarus dF star
Number of posts : 3337 Registration date : 2008-06-12
| Subject: Re: 55 Cancri e -- Transits detected!! 26th September 2011, 5:38 pm | |
| Wonder how difficult it would be to get spectra. And whether there's a gas tail like HD 209458b.
Maybe the remnant of a more massive gas giant planet that's been eroded down? | |
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tommi59 Jovian
Number of posts : 596 Age : 46 Location : Baile Atha Cliath Registration date : 2010-07-31
| Subject: Re: 55 Cancri e -- Transits detected!! 27th September 2011, 9:50 am | |
| Low density similar to gj 1214 b??it is-ridiculous.It iseems to be weird even with lower mass assumed,density is still over 4.0g/cm3.Obvious this planet is remnant of bigger uranus like world with even more than 1000 km deep ocean of water | |
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Stalker Jovian
Number of posts : 540 Age : 33 Location : Paris, France Registration date : 2008-06-16
| Subject: Re: 55 Cancri e -- Transits detected!! 9th October 2011, 8:41 am | |
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Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Re: 55 Cancri e -- Transits detected!! 9th October 2011, 8:56 am | |
| That paper uses the conclusions from Winn et al's original paper here which is based off the original interpretation of the MOST data before they made corrections as described here. _________________ Caps Lock: Cruise control for 'Cool'!
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Stalker Jovian
Number of posts : 540 Age : 33 Location : Paris, France Registration date : 2008-06-16
| Subject: Re: 55 Cancri e -- Transits detected!! 9th October 2011, 11:07 am | |
| Problem is that masses pointed out in the article and in the release differ. What would mean that job made with Spitzer doesn't take into account the characteristics of the star of the article. _________________ | |
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tommi59 Jovian
Number of posts : 596 Age : 46 Location : Baile Atha Cliath Registration date : 2010-07-31
| Subject: Re: 55 Cancri e -- Transits detected!! 9th October 2011, 11:32 am | |
| Density similar to gj 1214 b? it sounds like neptune is similar to earth | |
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Stalker Jovian
Number of posts : 540 Age : 33 Location : Paris, France Registration date : 2008-06-16
| Subject: Re: 55 Cancri e -- Transits detected!! 9th October 2011, 1:27 pm | |
| and i cannot find the paper of the Spitzer release _________________ | |
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Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Re: 55 Cancri e -- Transits detected!! 9th October 2011, 1:34 pm | |
| - Sirius_Alpha wrote:
- That paper uses the conclusions from Winn et al's original paper here which is based off the original interpretation of the MOST data before they made corrections as described here.
Looking closer at the press release and papers, this doesn't seem to be the case. My mistake. I'm not sure what's going on. It looks like sloppy reporting. I think that since the two planets are both too low in density to be solid super-Earths without envelopes, they're grouping 55 Cnc e and GJ 1214 b in the same category. But I think we all agree that GJ 1214 b is far less dense than 55 Cnc e. _________________ Caps Lock: Cruise control for 'Cool'!
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tommi59 Jovian
Number of posts : 596 Age : 46 Location : Baile Atha Cliath Registration date : 2010-07-31
| Subject: Re: 55 Cancri e -- Transits detected!! 9th October 2011, 3:50 pm | |
| I understand because still contain some water but is almost 3 times more dense than gj 1214 but anyway is neverthelles remnant of bigger body.I am interested in super earth enough far to be beyond mass loss zone | |
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Stalker Jovian
Number of posts : 540 Age : 33 Location : Paris, France Registration date : 2008-06-16
| Subject: Re: 55 Cancri e -- Transits detected!! 10th October 2011, 2:49 am | |
| Whit the informations given in the Spitzer press release, we have a density similar to that of the earth _________________ | |
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Lazarus dF star
Number of posts : 3337 Registration date : 2008-06-12
| Subject: Re: 55 Cancri e -- Transits detected!! 10th October 2011, 3:55 am | |
| 55 Cnc e is also somewhat more massive than GJ 1214b so there would be more compression. Uncompressed density would probably be a better comparison to do, but harder to figure out. | |
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Lazarus dF star
Number of posts : 3337 Registration date : 2008-06-12
| Subject: Re: 55 Cancri e -- Transits detected!! 24th October 2011, 3:15 pm | |
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Edasich dK star
Number of posts : 2296 Location : Tau Ceti g - Mid Latitudes Registration date : 2008-06-02
| Subject: Re: 55 Cancri e -- Transits detected!! 25th October 2011, 4:22 am | |
| Well with a density of 4.6 g/cc I would think about a steamy watery planet but with a significant percentage of rock and heavy elements. Right? | |
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AVBursch Meteor
Number of posts : 18 Registration date : 2009-05-01
| Subject: Re: 55 Cancri e -- Transits detected!! 25th October 2011, 4:48 am | |
| - Edasich wrote:
- Well with a density of 4.6 g/cc I would think about a steamy watery planet but with a significant percentage of rock and heavy elements. Right?
Such a planet would be a "hot super-Pluto". Think of this as a bigger and hotter version of Pluto, in other words, a world composed of rock and ice. | |
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tommi59 Jovian
Number of posts : 596 Age : 46 Location : Baile Atha Cliath Registration date : 2010-07-31
| Subject: Re: 55 Cancri e -- Transits detected!! 25th October 2011, 5:07 am | |
| Remnant of neptune anyway.Neverthelles infrared radius for this planet should be correct radius not in visual light | |
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Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Re: 55 Cancri e -- Transits detected!! 8th May 2012, 5:53 pm | |
| Spitzer detection of the secondary eclipse. http://www.nasa.gov/home/hqnews/2012/may/HQ_12-138_Spitzer_Super_Earth.html - Quote :
- The results reveal the planet is likely dark and its sun-facing side is more than 2,000 Kelvin (3,140 degrees Fahrenheit), hot enough to melt metal.
The new information is consistent with a prior theory that 55 Cancri e is a water world: a rocky core surrounded by a layer of water in a "supercritical" state where it is both liquid and gas, and topped by a blanket of steam.
Spitzer discovered the sun-facing side is extremely hot, indicating the planet probably does not have a substantial atmosphere to carry the sun's heat to the unlit side. Edit, on arXiv now. Detection of Thermal Emission from a Super-Earth http://arxiv.org/abs/1205.1766 _________________ Caps Lock: Cruise control for 'Cool'!
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Stalker Jovian
Number of posts : 540 Age : 33 Location : Paris, France Registration date : 2008-06-16
| Subject: Re: 55 Cancri e -- Transits detected!! 9th May 2012, 3:25 am | |
| Dark because of the Rayleigh scattering? _________________ | |
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Lazarus dF star
Number of posts : 3337 Registration date : 2008-06-12
| Subject: Re: 55 Cancri e -- Transits detected!! 19th June 2012, 2:09 pm | |
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Sirius_Alpha Admin
Number of posts : 4320 Location : Earth Registration date : 2008-04-06
| Subject: Re: 55 Cancri e -- Transits detected!! 28th August 2012, 8:19 pm | |
| Revised mass and density estimate - still consistent with significant fraction of volatiles. 300 additional RV measurements provide no evidence for a sixth planet, but there is a weak signal at 131 days (low power, not statistically significant). http://arxiv.org/abs/1208.5709 _________________ Caps Lock: Cruise control for 'Cool'!
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Galzi Planetary Embryo
Number of posts : 87 Age : 38 Location : Venetia et Histria Registration date : 2012-06-03
| Subject: Re: 55 Cancri e -- Transits detected!! 29th August 2012, 2:49 pm | |
| Good, 55 Cancri e is the first very well costrained exoplanet in the Earth-Neptune radius range: Mass: 8.37 ± 0.38 Earth masses Radius: 2.17 ± 0.1 Earth radius Mean Density: 4.5 ± 0.2 g/cm³
In my opinion the planet is still more a sort of SuperEarth than a MiniNeptune; its mean density is definitely far closer to the Earth one (5.52 g/cm³) than Neptune one (1.64 g/cm³).
Also interesting to see the ± 30 days uncertainty about the orbital period of 55 Cancri d despite 23 years of data and 663 data points taken. | |
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| 55 Cancri e -- Transits detected!! | |
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