From: LARRY KLAES (ljk4_at_msn.com)
Date: Fri Jan 09 2004 - 18:17:16 PST
----- Original Message -----
From: bulletins_at_SkyandTelescope.com
Sent: Friday, January 09, 2004 7:54 PM
To: ljk4_at_msn.com
Subject: S&T's Weekly News Bulletin for January 9
========================================================================
* * * SKY & TELESCOPE's WEEKLY NEWS BULLETIN - January 9, 2004 * * *
========================================================================
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!
========================================================================
FOOTPRINT OF A MAGNETIC EXOPLANET
For the first time, astronomers appear to have identified an extrasolar
planet with a magnetic personality. The planet orbits HD 179949, a
6.3-magnitude solar-type star (spectral type F8) located 90 light-years
away in Sagittarius. After observing the star during three observing runs
in 2001-02, a Canadian team led by Evgenya Shkolnik (University of British
Columbia) has identified a hot spot that rotates around the star every
3.093 days -- exactly the same period with which the planet orbits the
star. The hot spot has kept right in step with the planet for more than
100 orbits.
"This is the first glimpse of a magnetic field of an extrasolar planet,"
said Shkolnik at a Wednesday press conference at the American Astronomical
Society meeting in Atlanta....
> http://SkyandTelescope.com/news/article_1151_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
DIVING GLOBULAR CLUSTER MAKES A STARRY SPLASH
Two astronomers have made a surprising and unsuspected cosmic connection
by suggesting that a naked-eye open star cluster in Scorpius was spawned
by the action of a binocular globular cluster in the neighboring
constellation Ara. Richard F. Rees Jr. (Westfield State College) and Kyle
M. Cudworth (Yerkes Observatory) propose that when the 6th-magnitude
globular NGC 6397 passed through the plane of the Milky Way some 5 million
years ago, it triggered the formation of the open cluster NGC 6231, which
marks the core of the large Scorpius OB1 Association. Rees and Cudworth
presented their proposal at the 203rd meeting of the American Astronomical
Society on Wednesday....
> http://SkyandTelescope.com/news/article_1150_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
MORE GALAXIES THAT JUMP THE GUN
Yet another group of astronomers has found signs that we don't know as
much as we thought about how galaxies formed after the Big Bang. An
international team has located a streamer of galaxies 300 million
light-years long that had already taken shape when the universe was only a
fifth of its present age -- at redshift 2.38, when the universe was just
2.8 billion years old.
Such a galaxy string would be no big deal in the present-day universe.
It's similar to the famous Great Wall of galaxies just a few hundred
million light-years away. But the best models of structure formation
predict no gatherings so big appearing so early in cosmic history. "The
universe was growing up faster than we thought it was," said Povilas
Palunas (McDonald Observatory), one of the discoverers, at the American
Astronomical Society meeting on Wednesday....
> http://SkyandTelescope.com/news/article_1149_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
EXPLAINING SUPERNOVA EXPLOSIONS
Time and again, astronomers have been embarrassed by the fact that they
don't really understand one of their most important tools, Type Ia
supernovae, which serve as invaluable "standard candles" for measuring
cosmic distances. But if new work announced Tuesday at the American
Astronomical Society meeting in Atlanta, Georgia, holds up, they may have
taken a big step in the right direction.
Because they can be used to measure distances as great as several billion
light-years, Type Ia supernovae have enabled cosmologists to gauge how
fast the universe is expanding and how the expansion rate has changed
through time. Six years ago, the exploding stars provided the first
evidence that the universe's expansion has been speeding up, due to an
all-pervasive "dark energy" that no one expected. Type Ia supernovae also
affect our daily lives: most of the iron in everything from frying pans to
steel girders was forged within these stellar furnaces.
But what are Type Ia supernovae, exactly...?
> http://SkyandTelescope.com/news/article_1147_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
A GALACTIC STRIPTEASE
Pity C153. Astronomers using a broad suite of instruments have caught this
spiral galaxy performing an involuntary striptease act as it plunges
through the heart of a massive galaxy cluster at nearly 2,000 kilometers
per second.
Images and spectra in radio, optical, and X-ray wavelengths show a galaxy'
s worth of gas being stripped from C153, creating a
200,000-light-year-long wake that resembles the tail of a comet. Countless
other galaxies have undoubtedly endured the same humiliation, which
explains why extremely massive galaxy clusters in the local universe
contain so few spirals....
> http://SkyandTelescope.com/news/article_1146_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
THE SUN'S CLOSEST TWINS
No two people are exactly alike, but if you were to sort through millions
of faces, you might find someone who is uncannily similar to you today,
others who are similar to you when you were younger, and some who look
exactly as you will in the future. You might learn a lot from these
people. Similarly, several astronomers at Villanova University think they
can learn a lot about our Sun by finding near-twins of it at all the
different stages expected in its long lifetime.
At the American Astronomical Society meeting, Edward Guinan described an
ongoing program called "The Sun In Time" that is identifying and studying
solar analogues. Working at every wavelength, from radio to X-rays, the
group is researching stars that have sizes, masses, temperatures, and
heavy-element contents that are similar to those of the present-day Sun --
as well as solar-twin stars at every age from birth onward....
> http://SkyandTelescope.com/news/article_1145_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
A TASTE OF THINGS TO COME
As more images come to Earth from the Spirit rover on Mars, astronomers
are being ever more tantalized by Gusev Crater. On Tuesday NASA released
the highest resolution picture ever taken of Mars. The mosaic image, 4,000
by 3,000 pixels, is of the area in front of the rover and was shot while
Spirit remained in its "seated" position. Engineers predict the rover
could start to roll to targets next week.
The detailed view shows rocks of various sizes and shapes. Most are
smooth, perhaps due to thousands of years of sand-blasting from Mars's
dusty winds....
> http://SkyandTelescope.com/news/article_1144_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
DISSECTING A MICROQUASAR
For 25 years astronomers have been scratching their heads over the
energetic binary star SS 433, a so-called microquasar in Aquila. And even
though lots of new data were unveiled Monday at the American Astronomical
Society meeting last week in Atlanta, Georgia, the experts are scratching
their heads still.
Astronomers are keenly interested in SS 433 because it seems to be a
miniature, million-times-scaled-down version of the engines that power
quasars and other active galactic nuclei. This bizarre system consists of
a fairly normal star and an extremely dense object -- either a neutron
star or a black hole -- that orbit each other every 13 days. A stream of
gas is spilling from the "normal" star into the dense companions's deep
gravitational field, where it swirls into a hot, brilliantly glowing disk.
Somehow, much of the material in the disk ends up within two narrow,
oppositely directed jets that shoot away from the collapsed object at a
quarter the speed of light.
That much has been known for years. But what type of star is fueling the
disk and jets? And is the compact object a neutron star or a black
hole...?
> http://SkyandTelescope.com/news/article_1143_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
OLD GALAXIES IN THE YOUNG UNIVERSE
Astronomers thought they had a nice, clear picture of how galaxies formed
billions of years ago -- but now the picture is suddenly turning muddy. A
team studying the faintest galaxies ever to have their spectra taken is
finding far too many big, mature galaxies similar to our Milky Way much
too early in cosmic history. "Theorists are not yet at the point of panic,
but they're getting there," team member Roberto Abraham (University of
Toronto) told a press conference at the American Astronomical Society
meeting being held last week in Atlanta....
> http://SkyandTelescope.com/news/article_1142_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
THE MOST MASSIVE STAR
There's no Guinness Book of Astronomy Records, but if there were, Stephen
Eikenberry (University of Florida) thinks he would have a new entry for
it. At the January 2004 American Astronomical Society meeting in Atlanta,
Eikenberry claimed to have identified the most massive and perhaps the
most luminous star ever discovered....
> http://SkyandTelescope.com/news/article_1141_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
PLOTTING SPIRIT'S COURSE
Remember the name "Sleepy Hollow." In images released on Monday by
scientists working with the Spirit rover on Mars, the newly discovered,
light-colored feature (the first Spirit-site landmark to be given a name)
will likely be the initial objective for the rover when it starts to roll
around next week.
At a press conference on Monday, Mars Exploration Rover principal
investigator Steven W. Squyres (Cornell University) reported "more good
news." The craft is alive and healthy, and so far all its instruments
appear to be in perfect working order....
> http://SkyandTelescope.com/news/article_1140_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
COMET CATCHER
On January 2nd, after a nearly five-year journey, NASA's comet-catching
spacecraft Stardust successfully arrived at Comet 81P/Wild 2 and scooped
up dust samples before heading back to Earth. In the process it passed
through the comet's coma, snapped some images of the nucleus from the
scant distance of 240 kilometers (149 miles), and discovered some
surprising surface features....
> http://SkyandTelescope.com/news/article_1138_1.asp
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
ASTRO NEWS BRIEFS
Mars Express Fails to Hear Beagle 2
The first attempt for the European Space Agency's Mars Express orbiter to
hear from the Beagle 2 lander was unsuccessful. The spacecraft passed over
Beagle 2's landing site at about 12:15 Universal Time Wednesday (7:15 a.m.
Eastern Standard Time) but it did not detect a signal from below. "We have
not lost hope yet to contact Beagle 2," says ESA's director of science
David Southwood, who explained that additional attempts would be made.
"But we also know that it has landed on an unforgiving planet."
> http://SkyandTelescope.com/news/article_1148_1.asp
========================================================================
HIGHLIGHTS OF THIS WEEK'S SKY
* Last-quarter Moon on Wednesday January 14th.
* Saturn (magnitude -0.4, in Gemini) is just a couple weeks past
opposition.
* Mercury (magnitude 0) is having a good apparition in the dawn sky. Look
for it above the southeast horizon about 50 or 60 minutes before sunrise.
For details, see This Week's Sky at a Glance and Planet Roundup:
> http://SkyandTelescope.com/observing/ataglance/
========================================================================
TRANSIT OF VENUS: VENICE AND THE GRAND MEDITERRANEAN (Advertisement)
Join SKY & TELESCOPE as we cruise the Mediterranean and witness the first
transit of Venus in more than a century. Our group will disembark the ship
before dawn on the day of the transit, and we'll view the entire event
from our specially selected site on the picturesque island of Corfu.
Seven-night cruise-tour highlights include Venice, Padova Observatory,
Greek Isles, and Dubrovnik.
Contact Aram Kaprielian at TravelQuest International to reserve space now.
Toll free: 1-800-830-1998. Outside the US: +1 928-445-7745 or e-mail
aram_at_tq-international.com.
> http://www.tq-international.com/VeniceCruise/VeniceCruiseHome.htm
========================================================================
Copyright 2004 Sky Publishing Corp. S&T's Weekly News Bulletin is provided
as a free service to the astronomical community by the editors of SKY &
TELESCOPE magazine. Widespread electronic distribution is encouraged as
long as our copyright notice is included, along with the words "used by
permission." But this bulletin may not be published in any other form
without written permission from Sky Publishing; send e-mail to
permissions_at_SkyandTelescope.com or call +1 617-864-7360. More astronomy
news is available on our Web site at http://SkyandTelescope.com/news/.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
To change your address, unsubscribe from S&T's Weekly News Bulletin, or
subscribe to S&T's Skywatcher's Bulletin, which calls attention to
noteworthy celestial events, go to this address:
> http://SkyandTelescope.com/shopatsky/emailsubscribe.asp
=======================================================================
This archive was generated by hypermail 2.1.6 : Fri Jan 09 2004 - 18:31:05 PST