SETI Stellar Small Fry, or Wayward Planet?


Bob Cutter (bcutter@teal.csn.net)
Thu, 2 Sep 1999 13:05:12 -0600


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>Date: Thu, 02 Sep 1999 07:46:42 -0400
>To: "seti@onelist.com" <seti@onelist.com>, setitalk@klx.com,
> carlsagan@craigerware.avalon.net, bcutter@teal.csn.net
>From: Larry Klaes <lklaes@bbn.com>
>Subject: Stellar Small Fry, or Wayward Planet?
>Cc: "Dr. Stuart A. Kingsley" <skingsley@coseti.org>,
> Andrew LePage <lepage@visidyne.com>,
> "AllenTough@aol.com" <AllenTough@aol.com>,
> "Fractenna@aol.com" <Fractenna@aol.com>
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>STELLAR SMALL FRY, OR WAYWARD PLANET
>
>>From Andrew Yee <ayee@nova.astro.utoronto.ca>
>
>INSCiGHT
>
>[http://www.academicpress.com/inscight/08311999/grapha.htm]
>
>Tuesday, 31 August 1999, 5 pm PST
>
>Stellar Small Fry, or Wayward Planet?
>By Govert Schilling
>
>Astronomers have spotted a mysterious dark object the size
>of over a dozen Jupiters. Perhaps too light to be a brown
>dwarf, the smallest kind of star, the object could be a giant
>planet drifting alone through space. Many similar bodies could
>lurk in nearby space, say the astronomers, whose paper has
>been accepted by Astrophysical Journal Letters.
>
>Maria Zapatero Osorio of the Canaries' Institute of Astrophysics
>in La Laguna, Tenerife, and her colleagues found the object,
>dubbed S Ori 47, when they were observing a young star cluster
>in the constellation Orion. The stars, 1100 light-years away,
>all formed just a few million years ago, so S Ori 47 is still
>glowing with the heat generated when it was formed. The team
>measured its luminosity (0.2% of that of the sun) and surface
>temperature (some 1700 degrees Celsius); by plugging these
>measurements into theoretical models of how quickly objects of
>different masses should cool and fade after their formation, they
>concluded it could be anything from 10 to 20 Jupiter masses.
>
>That puts S Ori 47 in the gray zone; objects less than 13
>Jupiter masses are thought to be incapable of nuclear fusion,
>and are considered a planet; above that, they can be brown
>dwarfs.
>
>Regardless of its true nature, S Ori 47 appears to be no
>astronomical oddity. "Currently, we're observing much
>fainter candidates in the same cluster," says Zapatero Osorio.
>
>Because all cluster members are roughly the same age, the
>fainter ones are probably even less massive. If the cluster
>is typical for the galaxy at large, space must be heavily
>populated with such objects.
>
>"It's a very important discovery," says Kevin Luhman of the
>Harvard-Smithsonian Center for Astrophysics in Cambridge,
>Massachusetts, who himself is hot on the trail of extremely
>low-mass objects in another cluster. But he doubts that the
>objects are plentiful enough to account for the galaxy's
>"dark matter," the mysterious missing mass that seems to
>pull on the visible stars and gas.
>
> 1999 The American Association for the Advancement of Science
>
>[Extracted from INSCiGHT, Academic Press.]
>
>
>
>



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