Page 1 of 43 12311 ... LastLast
Results 1 to 30 of 1280

Thread: Interesting extrasolar planet discoveries

  1. #1
    Join Date
    Sep 2003
    Posts
    3,028

    Interesting extrasolar planet discoveries

    Gliese 581 c is not the only planet discovered recently.

    * XO-2b: is a fairly typical transiting planet discovered by the XO telescope. It orbits one of the components of a wide binary star.
    * HAT-2-b orbits the star HD 147506. It is by far the most massive and eccentric transiting planet discovered so far.
    * Corot-exo-1b is the first planet discovered by the COROT telescope. Even though it is more massive than Jupiter, it seems to be one the most inflated planet discovered so far (radius 1.5-1.8 times that of Jupiter).

    There are also been many regular radial velocity planet discoveries recently. So far in 2007 there have been almost as many discoveries as in the last year together (24 vs. 27). During the recent years and against predictions the number of new planets have been fairly constant between 26 and 34. Apparently that is changing, especially as lower-mass planets are being found more and more...

  2. #2
    Join Date
    Sep 2003
    Posts
    3,028
    Two new yet-to-be announced transiting planets:
    * 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.
    * 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.

  3. #3
    Join Date
    Sep 2003
    Posts
    3,028
    * HD 17092 b, a massive planet around the giant star HD 17092.

  4. #4
    Join Date
    Jul 2004
    Posts
    2,286
    This is one of my favorite exoplanet sites
    http://www.oklo.org/

    Some other interesting ones that happened some time back

    the Genesis planet - PSR B1620-26, it is thought to be almost 13 billion years old, discovery made thanks to Hubble

    Keck Observatory has confirms the existence of Jupiter-sized planet, spotted by a network of astronomers using regular backyard telescopes, planet named TrES-1

    2M1207b a direct image of an extra solar planet ?

    A bit off-topic but Sporally has a vote going when Earth-II will be found
    http://www.bautforum.com/showthread.php?t=51506

  5. #5
    Join Date
    Sep 2003
    Posts
    3,028
    The nickname of PSR B1620-26c is Methuselah, not "Genesis".

  6. #6
    Join Date
    Sep 2003
    Posts
    3,028
    The torrent continues...

    * 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.

  7. #7
    Join Date
    Sep 2003
    Posts
    3,028
    Nature news article about the flood of recent discoveries.

  8. #8
    Join Date
    Sep 2003
    Posts
    3,028
    That's weird... WASP-1, the parent star of the very large planet WASP-1b, appears to be very similar to HD 149026, whose super-hot planet is anomalously dense. Apparently HD 149026 b's properties cannot be explained simply by the star's excessive metallicity.

  9. #9
    Join Date
    Sep 2005
    Posts
    3,417
    Title: TrES-3: A Nearby, Massive, Transiting Hot Jupiter in a 31-Hour Orbit
    Authors: Francis T. O'Donovan, David Charbonneau, Gáspár Á. Bakos, Georgi Mandushev, Edward W. Dunham, Timothy M. Brown, David W. Latham, Guillermo Torres, Alessandro Sozzetti, Géza Kovács, Mark E. Everett, Nairn Baliber, Márton G. Hidas, Gilbert A. Esquerdo, Markus Rabus, Hans J. Deeg, Juan A. Belmonte, Lynne A. Hillenbrand, Robert P. Stefanik.

    We describe the discovery of a massive transiting hot Jupiter with a very short orbital period (1.30619 d), which we name TrES-3. From spectroscopy of the host star GSC 03089-00929, we measure T_eff = 5720 ± 150 K, logg=4.6 ± 0.3, and vsini < 2 km/s, and derive a stellar mass of 0.90 ± 0.15 M_sun. We estimate a planetary mass of 1.92 ± 0.23 M_Jup, based on the sinusoidal variation of our high-precision radial velocity measurements. This variation has a period and phase consistent with our transit photometry. Our spectra show no evidence of line bisector variations that would indicate a blended eclipsing binary star. From detailed modelling of our B and z photometry of the 2.5%-deep transits, we determine a stellar radius 0.802 ± 0.046 R_sun and a planetary radius 1.295 ± 0.081 R_Jup. TrES-3 has one of the shortest orbital periods of the known transiting exoplanets, facilitating studies of orbital decay and mass loss due to evaporation, and making it an excellent target for future studies of infrared emission and reflected starlight.

    Read more (39kb, PDF)

  10. #10
    Join Date
    Jul 2003
    Posts
    29,699
    I just did an article on TrES-3. There are almost too many stories to keep up with now.

    http://www.universetoday.com/2007/05...just-31-hours/

  11. #11
    Join Date
    Apr 2007
    Posts
    95
    It seems like most of the papers are strongly emphasizing each exoplanet's unique characteristics to try and stand out in the crowd. I guess this is a consequence of there being so many discoveries recently.

  12. #12
    Join Date
    Sep 2005
    Posts
    3,417
    Hum,
    that would imply that they were aware of the other stories that were perhaps going to be released...and if true - that would mean that they released them together on purpose.

    Motive: to stress out Fraser et al

  13. #13
    Join Date
    Jul 2003
    Posts
    29,699
    I was talking with the researchers for TrES-3 and they said that there wasn't going to be a press release. So that confirms it. Extrasolar planets aren't important enough to warrant a press release any more.

  14. #14
    Join Date
    Sep 2003
    Posts
    3,028
    Detection of transits of the nearby hot Neptune GJ 436 b

    This Letter reports on the photometric detection of transits of the Neptune-mass planet orbiting the nearby M-dwarf star GJ 436. It is by far the closest, smallest and least massive transiting planet detected so far. Its mass is slightly larger than Neptune's at M = 22.6 +- 1.9 M_earth. The shape and depth of the transit lightcurves show that it is crossing the host star disc near its limb (impact parameter 0.84 +- 0.03) and that the planet size is comparable to that of Uranus and Neptune, R = 25200 +- 2200 km = 3.95 +- 0.35 R_earth. Its main constituant is therefore very likely to be water ice. If the current planet structure models are correct, an outer layer of H/He constituting up to ten percent in mass is probably needed on top of the ice to account for the observed radius.

  15. #15
    Join Date
    Sep 2003
    Posts
    3,028
    systemic blog:

    [...] It is Gl 436 b that’s transiting, and this is easily the biggest planet-related discovery so far this year. New results from the Swiss team have been coming so thick and fast that it’s hard to even keep them all straight. Let me be the first to offer my heartfelt — and let’s admit it, envious — congratulations.

    [...]

    Gl 436 should be placed under constant photometric surveillance. If you’re capable of doing sub-1% photometry, please get out there on the sky whenever the night is clear and Gl 436 is at low air mass. If there are additional planets in the system, then it’s completely possible that they are transiting as well.

    In addition, it’s very important to collect the best possible time-series data for future Gl 436 transits. By timing when the transits occur, it will be possible to derive the orbital elements of significant additional perturbing bodies. This endeavor is within the reach of careful amateur and small-telescope observers.

  16. #16
    Join Date
    Sep 2003
    Posts
    3,028
    Quote Originally Posted by Fraser View Post
    I was talking with the researchers for TrES-3 and they said that there wasn't going to be a press release. So that confirms it. Extrasolar planets aren't important enough to warrant a press release any more.
    Actually not true... there are certainly no less extrasolar planet press releases than before, there's no point to make press releases of similar discoveries. We already know 20 transiting planets, so TrES-3 is no longer as big news. Another reason is that TrES-3 doesn't have the magic words "habitable" and "water". That doesn't mean it isn't important, of course.

    It is incredible if they don't make a press release about Gliese 436 b... *wink*

  17. #17
    Join Date
    Sep 2005
    Posts
    3,417

    Hot Neptune GJ 436 b

    Hum,
    interesting diagram in their paper.

    Planetary mass-radius diagram (adapted from Fortney et al. 2007) comparing the position of Solar System planets, transiting hot Jupiters (diamonds), and GJ 436 b. The lines indicate the position of the Fortney et al. models for different compositions: pure iron, pure silicate, pure water ice (with thermal profiles from Solar System planets), and models for irradiated planets at 0.1 AU from a Solar-type star with a fraction of 10%, 50% and 100% of Hydrogen/Helium. The dotted lines show the models for a cold (a = 10 AU) and very hot (a = 0.02 AU) pure H/He gas giant.
    (used under fair use policy)
    Attached Images Attached Images

  18. #18
    Join Date
    Jan 2005
    Posts
    2,930
    Wow...

    I agree with the blogger...Gl 436b is one of the biggest discoveries of the year; we've been looking for a Neptune-sized transiting planet for a long time. This could go a ways towards refining models of planetary size, density, and composition.

  19. #19
    Join Date
    Sep 2003
    Location
    The beautiful north coast (Ohio)
    Posts
    50,658
    Quote Originally Posted by Blob View Post
    Hum,
    interesting diagram in their paper.
    Very interesting. I know humans love to look for patterns, even when none exist, but it seems to me that one could make a pretty nice curve connecting the points on that graph. I just don't know exactly what it would mean - maybe something about formation mechanisms?
    At night the stars put on a show for free (Carole King)

    All moderation in purple - The rules

  20. #20
    Join Date
    Sep 2003
    Posts
    3,028
    I don't see anything odd in the diagram unless you don't count the puffed-up Jupiters and the super-dense HD 149026 b, whose origins are not yet explained. The seemingly exponential curve hardly means anything.

  21. #21
    Join Date
    Jul 2003
    Posts
    29,699
    I'll do an article on Gl 436b.

  22. #22
    Join Date
    Sep 2003
    Posts
    3,028

  23. #23
    Join Date
    Sep 2005
    Posts
    3,417
    Hum,
    ie water

    Images here of the L’Observatoire Fran&#231;ois-Xavier Bagnoud.

    Une &#233;quipe d’astronomes men&#233;e par un chercheur de l’Universit&#233; de Li&#232;ge a mesur&#233; le transit d’une petite plan&#232;te de la taille de Neptune en dehors de notre syst&#232;me solaire. La mesure de ce transit permet pour la premi&#232;re fois d’acc&#233;der &#224; la structure d’une plan&#232;te de petite taille, et a mis en &#233;vidence le fait qu’elle est compos&#233;e principalement d’eau, comme Uranus et Neptune.

  24. #24
    Join Date
    Sep 2003
    Posts
    3,028
    Hubble's astrometric measurements have shown that the massive planet HD 33636 b (minimum mass 9.3 MJup) is actually a low-mass star (142 ± 11 MJup).

    Interestingly, Spitzer had detected a dust disk around HD 33636. There was a press release some time ago about the discovery that dust disks are common around binaries.

  25. #25
    Join Date
    Jun 2003
    Posts
    8,795
    Quote Originally Posted by Blob View Post
    Hum,
    ie water
    Hot ice is H20, but not necessarily water, as I'm sure you know.
    The water at the bottom of an ocean hundreds of kilometers deep would be compressed into one of the many ices in this diagram, some of which can exist at high temperatures (particularly Ice VII)
    http://www.colorado.edu/physics/phys...ages/phase.gif

  26. #26
    Join Date
    Jul 2003
    Posts
    29,699
    Okay, there's GJ 436b covered
    http://www.universetoday.com/2007/05...-superhot-ice/

    Once again, no press release.

  27. #27
    Join Date
    Sep 2005
    Posts
    3,417
    Quote Originally Posted by eburacum45 View Post
    Hot ice is H20, but not necessarily water
    Hum,
    So no Kevin Costner...

    But, I came across this a while ago, (i may have even posted a thread about it here ....)...

    Supercomputer simulations by two Sandia researchers have significantly altered the theoretical diagram universally used by scientists to understand the characteristics of water at extreme temperatures and pressures.
    The new computational model also expands the known range of water’s electrical conductivity.
    The Sandia theoretical work showed that phase boundaries for “metallic water” — water with its electrons able to migrate like a metal’s — should be lowered from 7,000 to 4,000 kelvin and from 250 to 100 gigapascals.
    http://www.technologynewsdaily.com/node/4690

  28. #28
    Join Date
    Oct 2001
    Posts
    2,138
    Quote Originally Posted by Fraser View Post
    Okay, there's GJ 436b covered
    http://www.universetoday.com/2007/05...-superhot-ice/
    Once again, no press release.
    A non-technical Reuters article via CNN about GJ436b, the hot-solid-water-(but-not-cold)-ice planet.
    http://www.cnn.com/2007/TECH/space/0...eut/index.html

  29. #29
    Join Date
    May 2007
    Posts
    1,594
    Quote Originally Posted by eburacum45 View Post
    Hot ice is H20, but not necessarily water, as I'm sure you know.
    The water at the bottom of an ocean hundreds of kilometers deep would be compressed into one of the many ices in this diagram, some of which can exist at high temperatures (particularly Ice VII)
    http://www.colorado.edu/physics/phys...ages/phase.gif
    are you kidding ? water is water in every phase whatever our liquid water on earth or some hot ice on roasting mini uranus somewhere...it is still h2o so WATER....saying that h2o isnt water is like saying co2 is not carbon dioxide or 666 is no beast number

  30. #30
    Join Date
    Sep 2003
    Posts
    3,028
    Well, it didn't take long: the first amateur observation of the transit of Gliese 436 b.

Similar Threads

  1. More planet discoveries via microlensing!
    By folkhemmet in forum Astronomy
    Replies: 4
    Last Post: 2013-Mar-25, 03:05 PM
  2. First map of an extrasolar planet
    By Tom Mazanec in forum Astronomy
    Replies: 19
    Last Post: 2010-Mar-06, 05:01 PM
  3. Extrasolar planet seen?
    By Kullat Nunu in forum Astronomy
    Replies: 43
    Last Post: 2006-Jun-05, 05:06 PM
  4. Replies: 3
    Last Post: 2006-Jan-17, 08:17 PM
  5. Extrasolar planet seen?
    By Kullat Nunu in forum Astronomy
    Replies: 16
    Last Post: 2004-May-11, 10:58 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •