[meteorite-list] A New Nearby Oddball Planet
From: cdtucson at cox.net <cdtucson_at_meteoritecentral.com>
Date: Mon, 2 May 2011 19:35:03 -0400 Message-ID: <20110502193503.4Y3V2.351032.imail_at_fed1rmwml34> Sterling, It's Mostly Molybdenum along with a few heavier elements, based on the brownleeite that we know is out there. -- Carl or Debbie Esparza Meteoritemax ---- "Sterling K. Webb" <sterling_k_webb at sbcglobal.net> wrote: > Back in January, there was a List discussion of a planet > of the Kepler 10 (unnamed) star which has a density of > 8.8, as heavy as iron and an argument about whether > an entirely iron planet could exist and how. > > Now we have a (roughly) terrestial planet with a density > of 11.0, or about the density of a solid lead ball... Iron > ain't gonna do it. > > http://www.space.com/11544-densest-alien-planet-55cancrie.html > > Nearby Alien Planet Nearly Dense as Lead > > Astronomers have pinned down some details of an > exotic nearby alien planet that's almost as > dense as lead. > > The exoplanet, called 55 Cancri e, is 60 percent > larger in diameter than Earth but eight times > as massive, researchers revealed Friday (April 29). > That makes the alien world the densest solid planet > known -- twice as dense as Earth. [2 x 5.5 = 11.0] > > Astronomers previously thought 55 Cancri e took > about 2.8 days to orbit its parent star. But the > new study reveals that the exoplanet is so close > to its host star that it completes a stellar lap > in less than 18 hours. > > "You could set dates on this world by your wristwatch, > not a calendar," study co-author Jaymie Matthews, > of the University of British Columbia, said in a statement. > > Updating views of 55 Cancri e: > > The super-dense alien world is part of a multiplanet > solar system about 40 light-years from Earth, in the > constellation Cancer (The Crab). Its sunlike parent > star, 55 Cancri, is bright enough to be seen from > Earth by the unaided eye, researchers said. > > This wide-angle photograph of the night sky shows > the location of 55 Cancri, a star where astronomers > have found five planets, including a hot, dense > super-Earth. > > This wide-angle photograph of the night sky shows > the location of 55 Cancri, a star where astronomers > have found five planets, including a hot, dense > super-Earth. > > Since 1997, astronomers have discovered five planets > circling 55 Cancri (including 55 Canrci e in 2004). > All five alien worlds were detected using the so-called > radial velocity -- or Doppler -- method, which looks > for tiny wobbles in a star's movement caused by the > gravitational tugs of orbiting planets. > > Initially, astronomers thought 55 Cancri e had an > orbital period of about 2.8 days. But last year, > two researchers -- Harvard grad student Rebekah > Dawson and Daniel Fabrycky of the University of > California, Santa Cruz -- re-analyzed the data. > They suggested that the alien planet might actually > zip around its host star much faster than that. > > So Dawson and Fabrycky joined up with a few others > to observe 55 Cancri e more closely. The team trained > Canada's MOST (Microvariability & Oscillations of STars) > space telescope on the planet's star, then watched > for the tiny brightness dips caused when 55 Cancri e > passed in front of -- or transited -- it from the > telescope's perspective. > > This is the same technique used by NASA's prolific > Kepler space observatory, which has found 1,235 > alien planet candidates since its March 2009 launch. > > The team found that these transits occur like clockwork > every 17 hours and 41 minutes, just as Dawson and > Fabrycky had predicted. The starlight is dimmed by > only 0.02 percent during each transit, telling the > astronomers that the planet's diameter is about > 13,049 miles (21,000 kilometers) -- only 60 percent > or so larger than Earth. > > Using this information, the researchers were able to > calculate 55 Cancri e's density. > > "It's wonderful to be able to point to a naked-eye > star and know the mass and radius of one of its planets, > especially a distinctive one like this," said study > lead author Josh Winn of MIT. > > The research was released online Friday at the website > arXiv.org, and it has been submitted for publication > in The Astrophysical Journal Letters. > > A scorching-hot world > > Because 55 Cancri e is so close to its parent star, > it wouldn't be a very pleasant place to live. > Temperatures on its surface could be as high as > 4,892 degrees Fahrenheit (2,700 degrees Celsius), > researchers said. > > "Because of the infernal heat, it's unlikely that > 55 Cancri e has an atmosphere," Winn said. "So this > is not the type of place where exobiologists would > look for life." > > If you could somehow survive the heat, however, > the view from the planet's surface would be > exotic and spectacular. > > "On this world -- the densest solid planet found > anywhere so far, in the solar system or beyond -- > you would weigh three times heavier than you do > on Earth," Matthews said. "By day, the sun would > look 60 times bigger and shine 3,600 times brighter > in the sky." > > But the appeal of 55 Cancri e is not limited to > such gee-whiz factoids. Because it's so close to > Earth, the planet and its solar system should > inspire all sorts of future work, researchers said. > > "The brightness of the host star makes many types of > sensitive measurements possible, so 55 Cancri e is > the perfect laboratory to test theories of planet > formation, evolution and survival," Winn said. > > ------------------------------------------------------------------------ > > With a surface temperature of nearly 5000F (or ~2700K), > this can't be a lead world -- it would have boiled away by > now. A solid iron planet would just barely survive -- iron > boils at 3134K. > > A planet of 75% iron with a 25% crust of Tungsten would > have a density of 11, and I suppose that if everything less > refractory than tungsten had boiled away, you could get > such a planet... > > Here's everything heavier than iron and its density. > > I got tired of entering boiling points but you can see > that the dense elements have high boiling points... > > Boiling points alone do not tell the story; vapor > pressures are high above the melting point and > such elements could slowly escape. > > Tungsten is the best bet. MP 3680K, BP 5828K. > and moderately abundant in the universe, about > like uranium. > > 76 Os Osmium 22.61 BP 5285K > 77 Ir Iridium 22.56 BP 4701K > 78 Pt Platinum 21.46 BP 5869K > 75 Re Rhenium 21.02 BP 5869 > 93 Np Neptunium 20.45 BP 4273K > 94 Pu Plutonium 19.84 BP 3501K > 79 Au Gold 19.282 BP 3129K > 74 W Tungsten 19.25 BP 5828K > 92 U Uranium 18.95 BP 4404K > 104 Rf Rutherfordium 18.1 > 73 Ta Tantalum 16.654 BP 5731K > 91 Pa Protactinium 15.37 > 98 Cf Californium 15.1 > 97 Bk Berkelium 14.79 > 95 Am Americium 13.69 > 80 Hg Mercury 13.5336 > 96 Cm Curium 13.51 > 99 Es Einsteinium 13.5 > 72 Hf Hafnium 13.31 > 45 Rh Rhodium 12.41 > 44 Ru Ruthenium 12.37 > 46 Pd Palladium 12.02 > 81 Tl Thallium 11.85 > 90 Th Thorium 11.72 > 43 Tc Technetium 11.5 > 82 Pb Lead 11.342 > 47 Ag Silver 10.501 > 42 Mo Molybdenum 10.22 > 89 Ac Actinium 10.07 > 71 Lu Lutetium 9.84 > 83 Bi Bismuth 9.807 > 69 Tm Thulium 9.321 > 84 Po Polonium 9.32 > 68 Er Erbium 9.066 > 29 Cu Copper 8.96 > 28 Ni Nickel 8.912 > 27 Co Cobalt 8.86 > 67 Ho Holmium 8.795 > 48 Cd Cadmium 8.69 > 41 Nb Niobium 8.57 > 66 Dy Dysprosium 8.55 > 65 Tb Terbium 8.229 > 64 Gd Gadolinium 7.895 > 26 Fe Iron 7.874 > > You put together a planet from the list... > > > Sterling > > ______________________________________________ > Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html > Meteorite-list mailing list > Meteorite-list at meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-listReceived on Mon 02 May 2011 07:35:03 PM PDT |
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