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Fwd: Re: Yahoo! News Story - Exoplanet Atmospheres Detected from Earth - Yahoo! News

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  • mahtezcatpoc
    OGLE-TR-056b (OGLE = Optical Gravitational Lensing Experiment, a Polish astronomical project based at Warsaw University
    Message 1 of 2 , Oct 28, 2009
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      (OGLE = Optical Gravitational Lensing Experiment, a Polish astronomical project based at Warsaw University


      "...chiefly concerned with discovering dark matter using the microlensing technique."



      RA 17h56m35.51s
      Declination -29 32' 21.2

      In Sagittarius, near the Scorpius and Ophiuchus borders, between Gamma Sagittarii (Alnasl) and Rho Ophiuchi.

      29 Sagittarius 24 (2000).


      (TrES = Transatlantic Exoplanet Survey




      RA 17h 52m 07s
      Declination +37 32′ 46″

      In Hercules, near Pi and 69 Herculis.

      26 Sagittarius 55 (2000).

      Mark A. Holmes

      --- In thefixedstars@yahoogroups.com, "mahtezcatpoc" <mahtezcatpoc@...> wrote:
      > --- In Centaurs2@yahoogroups.com, "mahtezcatpoc" <mahtezcatpoc@> wrote:
      > --- In Centaurs2@yahoogroups.com, Mark Holmes <mahtezcatpoc@> wrote:
      > >
      > > Mark Holmes (mahtezcatpoc@) has sent you a news article.
      > > (Email address has not been verified.)
      > > ------------------------------------------------------------
      > > Personal message:
      > >
      > >
      > >
      > > Exoplanet Atmospheres Detected from Earth - Yahoo! News
      > >
      > >
      > http://news.yahoo.com/s/space/20090114/sc_space/exoplanetatmospheresdetectedfromearth
      > Exoplanet Atmospheres Detected from Earth
      > Andrea Thompson
      > Senior Writer
      > SPACE.com andrea Thompson
      > – Wed Jan 14, 3:27 pm ET
      > Two independent groups of astronomers have detected the atmospheres of
      > planets around other stars from ground-based telescopes.
      > Previous observations of the atmospheres of extrasolar planets had
      > been made almost entirely by space-based instruments, such as the
      > Hubble and Spitzer space telescopes, although another team last year
      > detected the signature of sodium in an exoplanet atmosphere.
      > To date, astronomers have detected several key gases in planets'
      > atmospheres, including:
      > * Carbon dioxide – a potential sign of life, though the planet
      > where the gas was observed was too hot to be habitable.
      > * Water vapor – a key molecule required to support life as we know it.
      > * Silicates (combinations of silicon and oxygen) – components of
      > most rocks on Earth, likely in the form of clouds of dust grains on
      > massive exoplanets.
      > * Sodium – detected in 2001, it marked the first space-based
      > observation of an exoplanet atmosphere.
      > Ground-based detection is becoming a priority as Hubble ages and
      > Spitzer is set to run out of cryogens, which keep its instruments cool
      > enough to detect infrared radiation (heat), limiting its abilities.
      > "Others have tried to detect planetary atmospheres from Earth, but to
      > no avail," said the co-author of one of the new studies, Mercedes
      > López-Morales of the Carnegie Institution in Washington, D.C. "We hit
      > it right two nights last summer."
      > López-Morales and her team observed the planet OGLE-TR056b, a
      > so-called "hot Jupiter."
      > Hot Jupiters
      > Hot Jupiters are massive gaseous planets that orbit very close to
      > their stars, whipping around them in two to three days. Their
      > proximity to their parent stars indicates the planets are hot enough
      > to emit radiation in the optical and near-infrared wavelengths and
      > that their radiation is detectable from Earth.
      > But OGLE-TR056b is faint, sitting about 5,000 light-years away and in
      > a crowded part of the night sky, located in the direction of the
      > center of our galaxy from the Earth's perspective. So López-Morales
      > and her colleagues used the European Southern Observatory's Very Large
      > Telescope (on July 2) and Carnegie's Magellan-Baade telescope (on Aug.
      > 3). Both telescopes are located in Chile.
      > Only about one out of every 3,000 photons from the star comes from the
      > planet itself. The rest is from the overwhelming light of the star. So
      > astronomers wait until the planet is eclipsed as it orbits behind the
      > star (from the Earth's perspective), which allows for separation of
      > the emissions of the planet from those of the star.
      > "The planet is glowing red-hot like a kitchen stove burner, but we had
      > to know precisely when the eclipse was going to happen and measure the
      > stellar flux very accurately so it could be removed to reveal the
      > planet's thermal emissions," said lead author of the study David Sing
      > of Institut d'Astrophysique de Paris.
      > Real hot
      > The team took more than 600 images of OGLE-TR056b with both
      > telescopes. The planet is hotter than any detected by Spitzer so far —
      > its atmosphere is more than 4,400 degrees Fahrenheit (2,400 degrees
      > Celsius).
      > The observations also indicated that the planet has little to no cloud
      > cover and a static atmosphere with little circulation, López-Morales
      > told SPACE.com in an email.
      > Their work will be detailed in an upcoming issue of the journal
      > Astronomy & Astrophysics.
      > In the same issue of the journal, a Dutch team will explain their
      > detection of the thermal emission in the near-infrared of another
      > exoplanet dubbed TrES-3b. Its atmosphere registered at about 3,000 F
      > (1,700 C).
      > --- End forwarded message ---
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