From: TerryMosel@aol.com
Date: 13 November 2006 22:08:17 GMT
Subject: IAA Lecture, Leonids, Astronomy news,

Hi all,
 
1. IAA Lecture: The next IAA public lecture will be by Deirdre
Kelleghan, President of the IAS, on Wednesday 15 November, in
Stranmillis College, Stranmillis Road, Belfast. The title will be "JPL's
Robot Explorers" and it will look at some of the amazing spacecraft of
the USA's Jet Propulsion Laboratory, which are exploring the Solar
System. It's at 7.30 p.m., admission free, including light
refreshments, and all are welcome.

2. LEONIDS: Don't forget the 'normal'  Leonids maximum on Nov 17. This
shower is active between 15 and 20 November each year, and produces
respectable activity even in those years when no storm activity is
expected. In 2006, the regular maximum should occur around Nov 17d 23h
UT, with a ZHR of about 15 if we are lucky. Then there's the brief
intense burst expected early on Nov 19, as already notified, but
repeated here for convenience:  BRIEF HIGH LEONID ACTIVITY for Nov 19?
Dr David Asher of Armagh Observatory calculates that we may have a brief
period of much enhanced meteor activity from the Leonids on the morning
of 19 November. David has a great track record of predicting activity
from particular filaments of material within the overall Leonid meteor
stream, usually getting the time of peak activity right to within 5-10
minutes, which is remarkable!  The Leonids are associated with comet
Tempel-Tuttle, and are just about the fastest of all known meteor
showers, as they collide with the Earth almost head-on, with entry
speeds of around 250,000 kph. Thus they are very swift, and rarely last
for more than 0.5 seconds (although the 'trains' they leave behind can
last for many seconds, or even some minutes). The radiant, or point in
the sky from which the meteors appear to come, lies in the East side of
the 'Sickle of Leo'. The normal Zenithal Hourly Rate for the Leonids is
only about 10 - 15, but they have also produced the greatest meteor
showers - or 'storms' on record!  The comet has a period of about 33
years, and much higher than normal rates therefore tend to occur about
every 33 years or so, when Earth encounters the densest part of the
stream of particles released by the comet each orbit. For example,
there were displays of about 250-300 per hour in 1998, 3,700 p/h in
1999, and about 480 p/h in 2000. But the greatest display of all in
modern times was in 1966, when they produced an astonishing rate of
about 140,000 p/h for a brief period as seen from Western USA!  We
don't expect anything like that at all this year, but David predicts
that we might get a ZHR of about 120 during a brief period at around
04.45 (+/- 10 minutes), on Nov 19.

3. SPITZER AND HUBBLE CREATE COLORFUL MASTERPIECE  NASA's Spitzer and
Hubble Space Telescopes have teamed up to expose the chaos that baby
stars are creating 1,500 light-years away in the Orion nebula. This
striking infrared and visible-light composite indicates that four
monstrously massive stars at the center of the nebula may be the main
culprits in the familiar Orion constellation.  
Link

4. GRAVITY HELPS REVEAL A JEWEL OF THE EARLY UNIVERSE  A team from the
Sloan Digital Sky Survey and Fermi National Accelerator Laboratory has
announced discovery of the brightest known image of a galaxy from the
early universe. While furious star formation makes the galaxy luminous,
it enters the record books because the gravity of a foreground galaxy
acts as a gravitational lens, focusing its light on the earth.
Link

5. EARLY EARTH'S HAZE MAY HAVE SPURRED LIFE, STUDY SAYS  Hazy skies on
early Earth could have provided a substantial source of organic material
useful for emerging life on the planet, according to a new study led by
the University of Colorado at Boulder. The laboratory experiment modeled
conditions measured by the Huygens probe on Saturn's moon, Titan.
Link

6. MONSTER STELLAR FLARE DWARFS ALL OTHERS SEEN  Scientists using
NASA's Swift satellite have spotted a stellar flare on a nearby star so
powerful that, had it been from our sun, it would have triggered a mass
extinction on Earth. The flare was perhaps the most energetic magnetic
stellar explosion ever detected. 
Link

Clear skies,

Terry Moseley

Last Revised: 2006 November 14th WWW contact:webmaster@arm.ac.uk

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