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Ärende: S&T's Weekly News B 01/0
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 * * * SKY & TELESCOPE's WEEKLY NEWS BULLETIN - August 27, 2004 * * *

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Welcome to S&T's Weekly News Bulletin. Images, the full text of stories
abridged here, and other enhancements are available on our Web site,
SkyandTelescope.com, at the URLs provided below. (If the links don't work,
just manually type the URLs into your Web browser.) Clear skies!

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TINY TELESCOPE FINDS BIG PLANET

Until now, all of the 125 or so known extrasolar planets were discovered
with large telescopes equipped with cutting-edge detectors. But an
international team has identified a planet circling a distant star using
mostly off-the-shelf equipment and a 4-inch Schmidt telescope. In fact,
team coleader Timothy Brown (National Center for Atmospheric Research)
assembled the discovery telescope and fine-tuned its optics in the garage
of his Colorado home....

> http://SkyandTelescope.com/news/article_1330_1.asp

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SEDNA'S ORIGIN SOLVED?

Last year astronomers discovered what's probably the biggest body found in
the solar system since Pluto in 1930, and they didn't know what to make of
it. Sedna, as 2003 VB12 was informally named, is about half the size of
the Moon and ranges from 75 to 985 astronomical units from the Sun in a
highly elliptical orbit. Neptune, by comparison, is 30 a.u. from the Sun,
Pluto averages 40 a.u., and the icy objects populating the Kuiper Belt
drop off sharply after 55.

So how did Sedna get way out there? It couldn't have formed in place; the
Sun's protoplanetary disk was too sparse that far out. Now Alessandro
Morbidelli (Cote d'Azur Observatory) and Harold F. Levison (Southwest
Research Institute) have analyzed various theories in detail....

> http://SkyandTelescope.com/news/article_1326_1.asp

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PERSEIDS PEAK AS PREDICTED

This is an exciting time to be a meteor observer. Scientists have long
known that a meteor shower occurs when the Earth passes through the trail
of debris strewn behind a comet as it orbits the Sun, but until a few
years ago they could only guess what would happen during any given shower.
Skilled observers would note unexpected outbursts and lulls, but nobody
knew how to use that data. Now, experts in orbital dynamics have started
to analyze the fine structure of these cometary debris trails and predict
fluctuations in meteor activity with extraordinary accuracy....

Now meteor prediction has scored another success. Esko Lyytinen of Finland
and Tom Van Flandern of Washington, DC, forecast an unusually brief and
intense peak in the 2004 Perseids due to a filament of debris cast off
when Comet Swift-Tuttle swept by the Sun in 1862. They also predicted that
the normal peak of this shower would be stronger than usual due to a
12-year resonance with Jupiter's orbit.

Preliminary analysis of data from 107 observers in 27 countries by Rainer
Arlt of the International Meteor Organization confirm both of those
predictions....

> http://SkyandTelescope.com/observing/objects/meteors/article_1329_1.asp

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ASTRO NEWS BRIEFS

Astronomers Find Lightweight Exoplanet

The European planet-hunting team led by Michel Mayor (Geneva Observatory,
Switzerland) has announced a low-mass planet orbiting the 5th-magnitude
southern star Mu Arae. The planet has a minimum mass of just 14 Earths,
almost identical to the mass of Uranus. It races around the solar-type
star every 9.5 days at an average distance of just 0.09 astronomical unit.
Because we do not know the inclination of the planet's orbit, its most
likely mass is actually about 17 or 18 Earths, similar to Neptune. This
object is the lightest planet discovered outside the solar system other
than the three terrestrial-mass bodies orbiting the pulsar B1257+12. Mu
Arae also has a previously discovered, Jupiter-mass planet in a 650-day
orbit, and there are strong indications of another planet even farther
out.

Like the vast majority of the 140 or so known extrasolar planets,
astronomers discovered this new object by tracking back-and-forth Doppler
shifts in the star's spectrum induced by the planet's gravitational pull.
The detection method does not reveal whether the planet is a large ball of
rock and iron (a so-called "super-Earth"), a gas giant like Jupiter and
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