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Thread: Interesting extrasolar planet discoveries

  1. #31
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    The gravity of Gl 436 b is given in the paper as 'log g= 5.0 dex';

    what does that mean in Earth gravities again? (sorry, I have forgotten- must be getting old).

  2. #32
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    You have to be careful when talking about 'ice' because any substance which is fluid in normal experience can be called ice when it freezes; water, CO2, ammonia, even oxygen and nitrogen. (frozen nitrogen could be found on Triton, apparently). So 'water ice' is probably the most accurate description of the stuff under Gl 436b's hypothetical ocean.
    Last edited by eburacum45; 2007-May-20 at 11:51 AM.

  3. #33
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    Using an on-line calculator I find that the gravity is about 1.43 gees, by the way. Not that excessive...

  4. #34
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    Quote Originally Posted by Kullat Nunu View Post
    * Two Jovian planets around the ancient (10 Ga) star HD 155358. It is the most metal-deficient star (20% of Sun's metallicity) known to have planets.
    McDonald Observatory news release: Astronomers Discover Multi-Planet System; May Alter Theories of Planet Formation

  5. #35
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    28 New Exoplanets and Four Multi-Planet Systems

    The world's largest and most prolific team of planet hunters announced today (Monday, May 28) the discovery of 28 new planets outside our solar system, increasing to 236 the total number of known exoplanets.
    So, the California/Carnegie Team hasn't been idle...

  6. #36
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    Some All of the planets were announced earlier...

  7. #37
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    Quote Originally Posted by Kullat Nunu View Post
    * XO-3b (not yet announced) resembles HAT-2-b in the sense it has an eccentric orbit (e ~ 0.2) and it is very massive (12 MJ, near the brown dwarf border). Since its host star is metal-poor, it is possible that it is actually a brown dwarf.
    Space.com: Oddball Planet Puzzles Astronomers

    A team of amateur and professional astronomers has discovered a mammoth orb more than 13 times the mass of Jupiter that whips around its parent star in fewer than four days and is considered an "oddball" planet among its exoplanet relatives.

  8. #38
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    Quote Originally Posted by Kullat Nunu View Post
    * TrES survey has found its third planet. TrES-3 is "a nearby, massive, transiting hot Jupiter in a 31-hour orbit". No further information available.
    Lowell Observatory: Massive Transiting Planet with 31-hour Year Found Around Distant Star

    Flagstaff, Ariz. An international team of astronomers with the Trans-atlantic Exoplanet Survey today announce the discovery of their third planet, TrES-3. The new planet was identified by astronomers looking for transiting planets that is, planets that pass in front of their home star using a network of small automated telescopes in Arizona, California, and the Canary Islands. TrES-3 was discovered in the constellation Hercules about 10 degrees west of Vega, the brightest star in the summer skies.

  9. #39
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    Steinn Sigurdsson from the Dynamics of Cats blogs is attending on an extrasolar planet conference in Santorini, Greece and has some very interesting reports:

    * First true Jupiter analog confirmed
    * Strong evidence of planet around a white dwarf

  10. #40
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    One of the big XP questions is how common our freakish system layout is. If it turns out to be as common as one in three, then I'll have to eat serious crow.
    "Occam" is the name of the alien race that will enslave us all eventually. And they've got razors for hands. I don't know if that's true but it seems like the simplest answer."

    Stephen Colbert.

  11. 2007-Jun-27, 03:22 PM
    Reason
    duplicate

  12. #41
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    No doubt, others have already done this, but in case they haven't....

    Another how many approach to XPs is the use of mathematical extrapolation of the discovery rate.

    Assuming discovery technology only maintains the rate and does not accelerate it - the easy ones, afterall, are limited in supply - then the following XP number is what might be awaiting us...

    Code:
    Year	Discoveries	Total
    1989	1	1
    1990	0	1
    1991	0	1
    1992	3	4
    1993	0	4
    1994	1	5
    1995	1	6
    1996	6	12
    1997	1	13
    1998	7	20
    1999	10	30
    2000	19	49
    2001	12	61
    2002	34	95
    2003	26	121
    2004	29	150
    2005	32	182
    2006	28	210
    2007	50	260
    2008	83	343
    2009	79	422
    2010	91	513
    2011	105	618
    2012	132	750
    2013	147	897
    2014	192	1,088
    2015	238	1,327
    2016	295	1,622
    2017	361	1,983
    2018	407	2,390
    2019	478	2,868
    2020	601	3,469
    I used 50 for 2007 as a guess based on 31 so far for the year. I don't have the months of discovery for comparison. Are more announcements made earlier than the year. If, however, the latter part of the year is about the same as the first half, then 62 should could be a better number. Using 62 for 2007, then we have...

    Code:
    Year	Discoveries	Total
    1989	1	1
    1990	0	1
    1991	0	1
    1992	3	4
    1993	0	4
    1994	1	5
    1995	1	6
    1996	6	12
    1997	1	13
    1998	7	20
    1999	10	30
    2000	19	49
    2001	12	61
    2002	34	95
    2003	26	121
    2004	29	150
    2005	32	182
    2006	28	210
    2007	62	272
    2008	90	362
    2009	87	449
    2010	102	551
    2011	120	670
    2012	154	824
    2013	175	1,000
    2014	233	1,233
    2015	296	1,529
    2016	372	1,901
    2017	459	2,360
    2018	517	2,878
    2019	631	3,509
    2020	806	4,315
    Interesting, but I don't intend to suggest it is likely, or unlikely, just interesting.

    [Edit: I quickly realized I had an error and this is the corrected extrapolation]

    [Added: Shoot!, it is wrong, too. It is stricly linear! Dang. I used linear interpolation (all I found on Quatro Pro).

    It is now based on the Growth function. Hopefully, this is more mature.

    Source is: http://vo.obspm.fr/exoplanetes/encyclo/catalog-all.php ]
    Last edited by George; 2007-Jun-27 at 05:25 PM.
    We know time flies, we just can't see its wings.

  13. #42
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    Quote Originally Posted by Kullat Nunu View Post
    Ooo, now THAT is very interesting. Because as they say, if it really is a Jupiter analogue then it might have rocky planets closer in.

  14. #43
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    Quote Originally Posted by parallaxicality View Post
    One of the big XP questions is how common our freakish system layout is. If it turns out to be as common as one in three, then I'll have to eat serious crow.
    The difference between reason and dogma is the ability to eat crow.

  15. #44
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    Nice. No doubt, crow will be a common exoplanet life form.
    We know time flies, we just can't see its wings.

  16. #45
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    Quote Originally Posted by George View Post
    Another how many approach to XPs is the use of mathematical extrapolation of the discovery rate.
    I wonder what basis you use when extrapolating the numbers. The increase of discoveries reached 34 in 2002 (the maximum so far) and has leveled since. This year may prove to be the most successful so far, but the predicted flood of transiting planets is yet to come.

    PS. Regarding the Jupiter analog, it is told that the Europeans have detected similar candidates that they're going to publish in the coming months.

  17. #46
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    Quote Originally Posted by Kullat Nunu View Post
    I wonder what basis you use when extrapolating the numbers. The increase of discoveries reached 34 in 2002 (the maximum so far) and has leveled since.
    Yes, this still holds true, apparently. The current count seems to be 31 so far for 2007. [The ref. link was added to the bottom of my post. Clicking on the "Discovery" year will sort by year for easy counting.]

    I took the liberty of assuming about 50 for the total for 2007 (19 more for the second half). This, I hope, is too modest. The second table simply doubles the number for the second half.

    Of course, the variables affecting the future count are many, but I assume they will be even more favorable than the simple geometric growth table. Your thread spurred my interest in trying something like this (for grins, mainly).

    This year may prove to be the most successful so far, but the predicted flood of transiting planets is yet to come.
    Care to insert an annual prognostication? If so, I will be happy reshuffle the cards and offer the extrapolation table.
    We know time flies, we just can't see its wings.

  18. #47
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    Quote Originally Posted by George View Post
    Care to insert an annual prognostication? If so, I will be happy reshuffle the cards and offer the extrapolation table.
    No, I can't make even a remotely reasonable guess.

    I don't remember the original numbers but by now there should be over a hundred SuperWASP planets. In reality, there are two of them and maybe a few dozen interesting but yet to be checked candidates.

  19. #48
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    Interesting times ahead:

    The Swiss group has 12 new planets, several with long ( > 2000 day) orbital period and apparent low eccentricities.
    They are seeing a deficit of planets with 10-100d orbital periods, which is interesting, things are piling up at multi-year periods as the searches go on for long enough to have senstivity out there.
    They cautiously extrapolate to ~ 25% of Sun-like stars having planets with Jupiter mass or above and with orbital radii of 3-20 AU. If you extrapolate the curve from the recent data, the percentage could be significantly higher.
    There is a hint of a peak in the eccentricity distribution at ~ 300d period (this is my interpretation of the collected data, not theirs) - ie the recent long period planets are trending to lower eccentricties, but this could be selection bias.

    They have another low metallicity star, HD171028, with a planet (~ 2 jupiter masses).
    There are now 13 known Neptune mass planets, with more candidates in the pipeline (30-50 candidates just in the HARPS data set)!
    HARPS is now reaching radial velocity measurement of better than 1 m/sec and may reach 0.1 m/sec for the brightest stars.
    They are seeing a lot of stellar "jitter" at the m/sec level - some of which is intrinsic, but some of which is actually unresolved signal from multiple or undersampled low mass planets!
    That's not all:

    In addition to the Jupier like planet (did I mention that I like that result...?)
    the California-Carnegie-AAT team has several more long period jovians, possibly with low eccentricity orbits.
    There are more low mass planets around K and M stars, but people are not announcing formally stellar identities until candidates are confirmed.
    Barnard's Star is "clean" (poor van de Kamp!) but Proxima Centauri may have something...

  20. #49
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    What? There's nothing around Barnard? Are they sure? Absolutely sure? Because I'd hate all that hope to be for naught. At least Planet X gave us Pluto.
    "Occam" is the name of the alien race that will enslave us all eventually. And they've got razors for hands. I don't know if that's true but it seems like the simplest answer."

    Stephen Colbert.

  21. #50
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    Yeah, Barnard is remarkable for its planetlessness. If it had any Jovian planets, they most likely would have been discovered by now.

    But since Barnard's Star is an extremely old metal-deficient star, this is not surprising.

    However... it seems that low-mass planets may be common around metal-deficient stars so there is still hope.

  22. #51
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    More planets around giant stars:

    The Penn State-Poland survey also reports, they have several detections and 30(!) candidate planets around a selection of field K giants; again long orbital periods.

  23. #52
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    Quote Originally Posted by Kullat Nunu View Post
    Yeah, Barnard is remarkable for its planetlessness. If it had any Jovian planets, they most likely would have been discovered by now.

    But since Barnard's Star is an extremely old metal-deficient star, this is not surprising.
    Hang on, I thought Barnard had a very big "wobble", I remember reading about it in the 80s at least. Or was that just instrument error? I know it's got a very high proper motion too, though that's nothing to do with planets.

  24. #53
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    No, it doesn't have any wobble. None whatsoever. That's why it is so ironic that it was once believed to have planets. van de Kamp's measurements were spurious.

  25. #54
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    More from the DoC: here, here, and here.

    Stuff like new transiting planets (including a Neptunian), hot Jupiters are pitch black, there may have been another Neptune in the Solar System, new lensing planets (to be announced really soon), big announcements coming, and lots of hush-hush.

  26. #55
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    Seems that some here are fans of Steinn's blog here too, which by the way, has a couple more fascinating updates today. See http://scienceblogs.com/catdynamics/...s_v_the_sa.php which seems to live up to what he has promised with regards to reporting on those Planet X speculations raised at the Conference from this reply to a query here http://scienceblogs.com/catdynamics/...ot.php#c482651

  27. #56
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    Quote: "Looks like the outer solar system, with late heavy bombardment, would have come together nicely if there was another Neptune out there to begin with."

    Now this could really be quite fascinating. I recall reading papers by the likes of Hal Levison where it was argued that the mass of all TNOs, SDOs, and LPCs added added up together cannot be more than a few Mearths at best. A far cry from the predicted 10-30 Mearths postulated to have existed in these nether regions i.e. the Edgeworth-Kuiper Belt (EKB), Scattered Disk in the beginning. Question is what happened to the missing mass (i.e. of these TNOs, SDOs, LPCs, etc)? And why do the solar system's outliers like dwarf planet Eris (ex Planet X), Sedna ala 2003 VB12 and CR 105 have such high orbital inclinations (i) of 44.187, 11.934 and 22.770 respectively? Or why are their orbits so eccentric (e.g. e=0.44177, e=0.855, e=0.798)? Also why the abrupt sharp edge to the Classical EKB at 50 AU? What could have produce it? Could there have been numerous factors at play with regards to these abnormalies? Or could any or all of these abnormalies be the by-products of a stellar flyby, BD or planetary mass (i.e. planemos) interlopers maybe even a Planet X? Why not a distant substellar mass BD common proper motion Solar companion?

    I have come across a paper by Morbadelli et al., where it was argued that a ~50 MJup rogue BD flyby can account for the perturbed orbits of some of these outer solar system bodies and they even suspect that Sedna could actually be but an extrasolar planetoid captured from this rogue BD. It begets the question i.e. let's assume that they are right, that indeed this BD interloper is the culprit responsible, but what if it wasn't simply just an interloper? What if it was of a lower mass and really but a highly eccentric (0.9 <= eBD <= 0.99), 13 MJup <= Mbd <=20 MJup coeval substellar mass BD companion to our Sun or maybe even a captured ultracool VLM substellar companion (given the likely birth of the Sun in an Orion like open cluster and the case of B1620-26c, this can't be entirely ruled out right?) with periastron at 100-200 AU instead? The Teff of such an object is likely to be only about ~360 K according to Burrows et al., and if it still around, could be near or at apastron at this moment i.e. almost a light year away. And if this is not enough, if we are still turning up more M Dwarfs from the RECONS project (e.g. http://www.noao.edu/outreach/press/pr06/pr0614.html) and elsewhere in this day and age, how very much more tedious is the task of locating objects with even lower masses and Teffs e.g. BDs with SpTs T and Y?

    Gomes et al. (Gomes, R. S., Matese, J. J., Lissauer, J. J., 2006, Icarus, 184, pp. 589-601), likewise have also come to a rather similar conclusion like Levision et. al., albeit one involving even lower masses perturbers and maybe with particular interest and relevance here is that one of the possibilities involves having a Neptune mass planet out at semiminor axis 2000 AU or a Jovian with semiminor axis at 5000 AU could explain the perturbed natured of many of the TNOs.

    References:
    Morbidelli, A., Levison, H. F., 2004, Scenarios for the Origin of the Orbits of the Trans-Neptunian Objects 2000 CR105 and 2003 VB12 (Sedna), AJ, 128, pp. 2564-2576

    Burrows, A., Marley, M., Hubbard, W. B., Lunine, J. I., Guillot, T., Saumon, D., Freedman, R.; Sudarsky, D., & Sharp, C., 1997, A Nongray Theory of Extrasolar Giant Planets and Brown Dwarfs, ApJ 491, p.856

    Gomes, R. S., Matese, J. J., Lissauer, J. J., 2006, A distant planetary-mass solar companion may have produced distant detached objects, Icarus, 184, pp. 589-601

    Links:
    http://en.wikipedia.org/wiki/Eris_(dwarf_planet)

    http://en.wikipedia.org/wiki/90377_Sedna

    http://en.wikipedia.org/wiki/2000_CR105

    http://en.wikipedia.org/wiki/PSR_B1620-26c

    http://www.noao.edu/outreach/press/pr06/pr0614.html

    http://adsabs.harvard.edu/abs/2004AJ....128.2564M

    http://adsabs.harvard.edu/abs/1997ApJ...491..856B

    http://www.sciencedirect.com/science...714c059b13149d

  28. #57
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    Quote Originally Posted by EDG_ View Post
    Hang on, I thought Barnard had a very big "wobble", I remember reading about it in the 80s at least. Or was that just instrument error? I know it's got a very high proper motion too, though that's nothing to do with planets.
    I remember reading about it too. And while you are at it, I believed Kamp also saw a large wobble in the motions of several other stars e.g. Ross 128 (iirc). However observations by other astronomers did not reproduced Kamp's results. They were dismissed as instrumental errors at Sproule indeed.

  29. #58
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    Quote Originally Posted by Kullat Nunu View Post
    More from the DoC: here, here, and here.

    Stuff like new transiting planets (including a Neptunian), hot Jupiters are pitch black, there may have been another Neptune in the Solar System, new lensing planets (to be announced really soon), big announcements coming, and lots of hush-hush.

    Quote: "Looks like the outer solar system, with late heavy bombardment, would have come together nicely if there was another Neptune out there to begin with."

    Now this could really be quite fascinating. I recall reading papers by the likes of Hal Levison where it was argued that the mass of all TNOs, SDOs, and LPCs added added up together cannot be more than a few Mearths at best. A far cry from the predicted 10-30 Mearths postulated to have existed in those nether regions i.e. the Edgeworth-Kuiper Belt (EKB), Scattered Disk in the beginning. Question is what happened to the missing mass (i.e. of these TNOs, SDOs, LPCs, etc)? And why do the solar system's outliers like dwarf planet Eris (ex Planet X), Sedna ala 2003 VB12 and CR 105 have such high orbital inclinations (i) of 44.187, 11.934 and 22.770 respectively? Or why are their orbits so eccentric (e.g. e=0.44177, e=0.855, e=0.798)? Also why the abrupt sharp edge to the Classical EKB at 50 AU? What could have producedit? Could there have been numerous factors at play with regards to these abnormalies? Or could any or all of these anomalies be the by-products of a stellar flyby, BD or planetary mass (i.e. planemos) interlopers maybe even a Planet X? Why not a distant substellar mass BD common proper motion Solar companion?

  30. #59
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    Hubble could easily have detected any deviations on Barnard Star's path. But as I already said, it doesn't mean it couldn't have terrestrial companions.

  31. #60
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    New discoveries:


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