=========================================================================<br /><br /> * * * * SKY & TELESCOPE's WEEKLY NEWS BULLETIN - May 24, 2002 * * * *<br /><br />=========================================================================<br />Welcome to S&T's Weekly News Bulletin. Images, the full text of stories<br />abridged here, and other enhancements are available on our Web site,<br />SkyandTelescope.com, at the URLs provided below. Clear skies!<br />=========================================================================<br /><br />BIG BANG PICTURE SHARPENS UP<br /><br />Astronomers on opposite sides of the world yesterday announced results<br />from two experiments studying the cosmic microwave background radiation<br />left over from the Big Bang. Both results firm up the grand picture that<br />cosmologists have put together in just the last few years: we live in a<br />flat universe filled mostly with exotic dark matter and dark energy, and<br />the cosmos apparently went through a brief moment of extreme inflation in<br />the first split second of its existence.<br /><br />On Thursday, two dozen cosmologists from Caltech and elsewhere announced<br />results from the Cosmic Background Imager (CBI) in the Andes....<br /><br />Not to be outdone, on the same day researchers in England released early<br />results from a microwave-background imager in the Canary Islands called<br />the Very Small Array....<br /><br />>
http://skyandtelescope.com/news/current/article_614_1.asp<br /><br />------------------------------------------------------------------------<br /><br />SUPERNOVAE AND GAMMA-RAY BURSTERS: ONE AND THE SAME?<br /><br />Evidence is mounting that at least some gamma-ray bursts, or GRBs -- the<br />most energetic outbursts of radiation known to science -- are generated by<br />supernovae, the relatively familiar if still stupendous explosions of<br />massive stars that have exhausted their nuclear fuel.<br /><br />In the last few years astronomers have traced GRBs to extremely distant<br />galaxies and determined that they pack enough punch to blow entire stars<br />apart. But experts remain in the dark about the events' true nature....<br /><br />One intriguing development is the discovery of a handful of GRBs that seem<br />to have originated from (or given rise to) supernovae. Arguably the best<br />case comes courtesy GRB 011121, a GRB that flared up in the far-southern<br />constellation Chamaeleon last November 21st....<br /><br />>
http://skyandtelescope.com/news/current/article_608_1.asp<br /><br />------------------------------------------------------------------------<br /><br />TENSIONS ERUPT ON MAUNA KEA<br /><br />Mauna Kea is, yet again, at the center of a dispute with local Hawaiians.<br />In a dramatic turn of events, on April 22nd the Office of Hawaiian Affairs<br />(OHA) filed suit against NASA over the construction of the Keck<br />Observatory "outriggers" -- six 1.8-meter telescopes that will be placed<br />adjacent to the twin 10-meter main instruments....<br /><br />Revered by native Hawaiians and environmentalists, the mid-Pacific peak is<br />home to an endangered insect species and was an ancient burial site. The<br />mountain also features rock-steady seeing, a plethora of cloudless nights,<br />and a lack of light pollution. Astronomers have built 13 observatories<br />atop Mauna Kea, with three more in the planning stages....<br /><br />>
http://skyandtelescope.com/news/current/article_607_1.asp<br /><br />------------------------------------------------------------------------<br /><br />ASTRONOMERS FLOCK TO NEW YORK FOR NEAF<br /><br />More than 2,100 amateur astronomers converged on Suffern, NY, last weekend<br />for the 11th annual Northeast Astronomy Forum and Telescope Show (NEAF) to<br />see the latest in telescope equipment, software, and accessories from more<br />than 60 vendors. "This was the highest turnout yet for the show," says<br />NEAF organizer Alan Traino.<br /><br />In addition to the exhibitors, the highlight of this year's event was the<br />keynote speaker, astronaut John Grunsfeld, who spoke of his recent<br />experience servicing the Hubble Space Telescope....<br /><br />>
http://skyandtelescope.com/news/current/article_606_1.asp<br /><br />------------------------------------------------------------------------<br /><br />ASTRO NEWS BRIEFS<br /><br />The Closest Brown Dwarf to a Star<br /><br />Hunts for extrasolar planets have turned up an interesting trend: a dearth<br />of brown dwarfs in close orbits around Sun-like stars. But this<br />"brown-dwarf desert" doesn't seem to apply to stars much smaller and<br />dimmer than the Sun. Using an adaptive-optics imager on Mauna Kea's<br />8-meter Gemini North telescope, Laird Close and others from the University<br />of Arizona surveyed 64 low-mass stars and found very dim companions very<br />near a dozen of them. "We find companions to low-mass stars are typically<br />only 4 astronomical units [about 600 million km] from their primary stars,<br />and this is surprisingly close together," says team member Nick Siegler.<br />Surveys made with the Hubble Space Telescope have found a similar trend<br />for dim pairs to be close, while more massive stars tend to have wider<br />stellar companions. The closest pairing found by Laird's team involves the<br />red dwarf LHS 2379A, located 46 light-years away in the constellation<br />Crater. A brown dwarf hovers just 3 astronomical units from the star in<br />the plane of the sky (their actual separation may be somewhat greater if<br />the companion is a little in front of or behind the primary).<br /><br />Europan Waters May Run Deep<br /><br />Planetary astronomers have been tantalized for two decades by the prospect<br />that a liquid ocean of organic-charged water lies beneath the icy exterior<br />of Jupiter's moon Europa. But efforts to answer the basic question "How<br />far down?" have been inconclusive, frustrating efforts to plan future<br />spacecraft that could tap into the reservoir by boring down from the<br />surface. A new analysis of crater depths by Paul M. Schenk (Lunar and<br />Planetary Institute), which appears in the May 23rd issue of Nature, is<br />further cause for despair. He compared impact features on Europa with<br />those on neighboring Ganymede and Callisto, which are also though to have<br />subsurface oceans. The shapes of craters more than 30 km across on Europa<br />and 150 km across on Ganymede undergo a transition from simple bowls to<br />nests of concentric ripples. Schenk believes this results from the<br />incoming projectile penetrating deeply enough to reach the water -- 80 km<br />down for Ganymede, and at least 19 km for Europa.<br /><br />Did an Impact Help The Dinosaurs?<br /><br />Most paleontologists now accept the premise that an enormous impact on<br />Earth led to the extinction of the dinosaurs (and most other species) 65<br />million years ago. But new research, published in the May 17th issue of<br />Science, suggests that a similar but much earlier mass-extinction event<br />created a evoutionary "window of opportunity" for dinosaur species. Fossil<br />evidence shows that large theropods and other dinosaurs proliferated<br />within just 100,000 years of the event and went on to dominate Earth's<br />life for 135 million years. Paul E. Olsen (Columbia University) led a team<br />that analyzed samples from more than 70 sites, most in eastern North<br />America. These revealed a previously undetected spike in the abundance of<br />iridium precisely at the Triassic-Jurassic boundary, 202 million years<br />ago. Because iridium is rare in Earth's crust, Olsen's team suggests that<br />it was delivered by an impacting comet or asteroid -- though a volcanic<br />source has not been completely ruled out.<br /><br />------------------------------------------------------------------------<br /><br />HIGHLIGHTS OF THIS WEEK'S SKY<br /><br />* Full Moon on May 26th.<br />* Penumbral lunar eclipse for Pacific Rim regions also on the 26th.<br />* Venus draws nearer to Jupiter; both are visible in the west-northwest at<br />twilight.<br /><br />For details, see This Week's Sky at a Glance and Planet Roundup:<br /><br />>
http://SkyandTelescope.com/observing/ataglance/<br /><br />------------------------------------------------------------------------<br />URANOMETRIA IS BACK (Advertisement)<br /><br />Make star hopping and galaxy hunting a snap with Uranometria 2000.0. The<br />long-awaited update to the classic atlas has more than double the number<br />of non-stellar objects of the previous edition and includes nearly 1,000<br />special "challenge" objects.<br /><br />Uranometria 2000.0, Volume 1: Deep Sky Atlas,<br /> The Northern Hemisphere to -6°<br />by Wil Tirion, Barry Rappaport, and Will Remaklus<br />>
http://SkyandTelescope.com/campaigns.asp?id=37<br /><br />Uranometria 2000.0, Volume 2: Deep Sky Atlas,<br /> The Southern Hemisphere to +6°<br />by Wil Tirion, Barry Rappaport, and Will Remaklus<br />>
http://SkyandTelescope.com/campaigns.asp?id=38<br /><br />Uranometria 2000.0, Volume 3: Deep Field Sky Guide<br />by Murray Cragin and Emil Bonanno<br />>
http://SkyandTelescope.com/campaigns.asp?id=39<br /><br />------------------------------------------------------------------------<br /><br />Copyright 2002 Sky Publishing Corp. S&T's Weekly News Bulletin is provided<br />as a free service to the astronomical community by the editors of SKY &<br />TELESCOPE magazine. Widespread electronic distribution is encouraged as<br />long as our copyright notice is included, along with the words "used by<br />permission." But this bulletin may not be published in any other form<br />without written permission from Sky Publishing; send e-mail to<br />permissions@SkyandTelescope.com or call +1 617-864-7360. More astronomy<br />news is available on our Web site at
http://SkyandTelescope.com/news/.<br /><br />------------------------------------------------------------------------<br /><br />To change your address, unsubscribe from S&T's Weekly News Bulletin, or<br />subscribe to S&T's Skywatcher's Bulletin, which calls attention to<br />noteworthy celestial events, go to this address:<br /><br />>
http://SkyandTelescope.com/shopatsky/emailsubscribe.asp<br /><br />========================================================================
