Dying, for stars, has just gotten more complicated.

For some stellar objects, the final phase before or instead of collapsing into a black hole may be what a group of physicists is calling an electroweak star.

Glenn Starkman, a professor of physics at Case Western Reserve University, together with former graduate students and post-docs De-Chang Dai and Dejan Stojkovic, now at the State University of New York in Buffalo, and Arthur Lue, at MIT's Lincoln Lab, offer a description of the structure of an electroweak star in a paper submitted to Physical Review Letters.

Ordinary stars are powered by the fusion of light nuclei into heavier ones -- such as hydrogen into helium in the center of our sun. Electroweak stars, they theorize, would be powered by the total conversion of quarks -- the particles that make up the proton and neutron building blocks of those nuclei -- into much lighter particles called leptons. These leptons include electrons, but especially elusive -- and nearly massless -- neutrinos.

"This is a process predicted by the well-tested Standard Model of particle physics," Starkman said. At ordinary temperatures it is so incredibly rare that it probably hasn't happened within the visible universe anytime in the last 10 billion years, except perhaps in the core of these electroweak stars and in the laboratories of some advanced alien civilizations, he said.

In their dying days, stars smaller than 2.1 times our sun's mass die and collapse into neutron stars -- objects dense enough that the neutrons and protons push against each other. More massive stars are thought to head toward collapse into a black hole. But at the extreme temperatures and densities that might be reached when a star begins to collapse into a black hole, electroweak conversion of quarks into leptons should proceed at a rapid rate, the scientists say.

The energy generated could halt the collapse, much as the energy generated by nuclear fusion prevents ordinary stars like the Sun from collapsing. In other words, an electroweak star is the possible next step before total collapse into a black hole. If the electroweak burning is efficient, it could consume enough mass to prevent what's left from ever becoming a black hole.

Most of the energy eventually emitted from electroweak stars is in the form of neutrinos, which are hard to detect. A small fraction comes out as light and this is where the electroweak star's signature will likely be found, Starkman, said. But, "To understand that small fraction, we have to understand the star better than we do."

And until they do, it's hard to know how we can tell electroweak stars from other stars.

There's time, however, to learn. The theorists have calculated that this phase of a star's life can last more than 10 million years -- a long time for us, though just an instant in the life of a star.

The northern coastline of Alaska midway between Point Barrow and Prudhoe Bay is eroding by up to one-third the length of a football field annually because of a "triple whammy" of declining sea ice, warming seawater and increased wave activity, according to new study led by the University of Colorado at Boulder.

The conditions have led to the steady retreat of 30 to 45 feet a year of the 12-foot-high bluffs -- frozen blocks of silt and peat containing 50 to 80 percent ice -- which are toppled into the Beaufort Sea during the summer months by a combination of large waves pounding the shoreline and warm seawater melting the base of the bluffs, said CU-Boulder Associate Professor Robert Anderson, a co-author on the study. Once the blocks have fallen, the coastal seawater melts them in a matter of days, sweeping the silty material out to sea.

Anderson, along with collaborators Cameron Wobus of Stratus Consulting and Irina Overeem of CU's Institute of Arctic and Alpine Research, or INSTAAR, each presented results from components of their study at the annual meeting of the American Geophysical Union in San Francisco held Dec. 14-18.

The problem is caused by several factors, including increased erosion along the Alaskan coastline due to longer ice-free summer conditions and warmer seawater bathing the coast, Anderson said. The third potential factor is that the longer the sea ice is detached from the coastline, the further out to sea the sea-ice edge will be. This open-ocean distance between the sea ice and the shore, known as the "fetch," increases both the energy of waves crashing into the coast and the height to which warm seawater can come into contact with the frozen bluffs, said Anderson.

"What we are seeing now is a triple whammy effect," said Anderson. "Since the summer Arctic sea ice cover continues to decline and Arctic air and sea temperatures continue to rise, we really don't see any prospect for this process ending."

In addition to Wobus and Overeem, co-authors on the studies include Gary Clow and Frank Urban of the U.S. Geological Survey in Lakewood, Colo., and Tim Stanton of the Naval Postgraduate School in Monterey, Calif.

The shoreline bluffs are made up of contiguous, polygon-shaped blocks, primarily made of permafrost and each roughly 70 to 100 feet across, he said. Ice "wedges" created by seeping summer surface water that annually freezes and thaws are driven deeper and deeper into the cracks between individual blocks each year. The blocks closest to the sea are undermined as warm seawater melts their base, and eventually split apart from neighboring blocks and topple during stormy conditions, said Anderson.

The researchers used a variety of instruments and methods in the study to examine the dynamic transition between the land and the sea, including time-lapse photography of shoreline erosion, global positioning systems (GPS), meteorological measurements including temperature and wind speed, and sediment analyses of the coastal bluffs. Offshore measurements included sea-ice distribution, ocean floor depth, sea-surface temperatures and wave dynamics, said Anderson, also a fellow at INSTAAR.

The time-lapse images were taken with four tripod mounted "game cameras" often used by hunters and wildlife biologists and which were set up parallel to the shoreline. The cameras snapped pictures every six hours during the 24-hour summer daylight months to track the effects of the waves on the coastline, said Anderson.

"Once one of these blocks topples, the process continues on to the next block," Anderson said. "These images are very powerful, because they pick up activity during severe storms when we aren't there to watch." The images also illustrate the steady melting along the water's edge that helps to undermine the bluffs even in the absence of storm activity.

The research team also deployed four submerged ocean buoys attached to metal sleds with sensors to measure the wave activity at different depths in the shallow coastal waters, comparing wave power with the shoreline fetch. The team attached temperature sensors to the buoy mooring lines to monitor seawater temperatures, which have been warming in recent summers due to increased solar radiation, he said.

When the sea ice is further from the shore, currents from the Beaufort and Chukchi seas transport warmer water to the coastline, said Anderson. While the temperature hovers around 45 degrees during the summer months, the shallow coastal water warmed to as much as 59 degrees during the 2007 field season -- the same year the largest loss of summer Arctic sea was recorded, he said.

As the ice wedges cut down through the polygon blocks, the surface soil above them -- which thaws each summer -- is pushed up slightly, forming small ridges that eventually surround each polygon, said Anderson. Small ponds form above individual polygons during the summer months as the surface ice and snow melts, providing habitat for migrating birds that feed and breed along the Beaufort Sea coastline.

"This is an important habitat for birds and other wildlife," said Anderson. "One of the concerns we have is that some larger ponds and lakes located slightly further inland may begin draining into the sea as the shoreline continues to recede."

While there are no towns adjacent to the specific study area, coastal erosion threatens abandoned military and petroleum infrastructure, he said. Coastal erosion occurs at similar sites elsewhere along Alaska's coastline. Bank stabilization measures using sandbags, for example, have been undertaken at the Alaskan town of Kaktovik on the Beaufort Sea in an attempt to slow the problem.

According to a 2009 CU-Boulder study, Arctic sea ice during the annual September minimum is now declining at a rate of 11.2 percent per decade. Only 19 percent of the ice cover was more than two years old -- the least ever recorded in the satellite record and far below the 1981-2000 summer average of 48 percent.

A galaxy located billions of light-years away is commanding the attention of NASA's Fermi Gamma-ray Space Telescope and astronomers around the globe. Thanks to a series of flares that began September 15, the galaxy is now the brightest source in the gamma-ray sky -- more than ten times brighter than it was in the summer.

Astronomers identify the object as 3C 454.3, an active galaxy located 7.2 billion light-years away in the constellation Pegasus. But even among active galaxies, it's exceptional.

"We're looking right down the barrel of a particle jet powered by the galaxy's supermassive black hole," said Gino Tosti at the National Institute of Nuclear Physics in Perugia, Italy. "Some change within that jet -- we don't know what -- is likely responsible for these flares."

Blazars, like many active galaxies, emit oppositely directed jets of particles traveling near the speed of light when matter falls toward their central supermassive black holes. What makes a blazar so bright in gamma rays is its orientation: One of the jets happens to be aimed straight at us.

Most of the time, the brightest persistent source in the gamma-ray sky is the Vela pulsar, which at a distance of about 1,000 light-years lies practically next door.

"3C 454.3 is millions of times farther away, yet the current flare makes it twice as bright as Vela," said Lise Escande at the Center for Nuclear Studies in Gradignan, near Bordeaux, France. "That represents an incredible energy release, and one the source can't sustain for very long."

According to Massimo Villata at Italy's Torino Observatory, 3C 454.3 also is flaring at radio and visible wavelengths, if less dramatically. "In red light, the blazar brightened by more than two and a half times to magnitude 13.7, and it is also very bright at high radio frequencies."

The Fermi team is alerting astronomers to monitor the event over as broad a range of wavelengths as possible. "That's our best bet for understanding what's going on inside that jet," Tosti said.

In ancient times, people with exceptional vision discovered that one of the brightest stars in the Big Dipper was, in fact, two stars so close together that most people cannot distinguish them. The two stars, Alcor and Mizar, were the first binary stars -- a pair of stars that orbit each other -- ever known.

Modern telescopes have since found that Mizar is itself a pair of binaries, revealing what was once thought of as a single star to be four stars orbiting each other. Alcor has been sometimes considered a fifth member of the system, orbiting far away from the Mizar quadruplet.

Now, an astronomer at the University of Rochester and his colleagues have made the surprise discovery that Alcor is also actually two stars, and is apparently gravitationally bound to the Mizar system, making the whole group a sextuplet. This would make the Mizar-Alcor sextuplet the second-nearest such system known. The discovery is especially surprising because Alcor is one of the most studied stars in the sky.

"Finding that Alcor had a stellar companion was a bit of serendipity," says Eric Mamajek, assistant professor of physics and astronomy at the University of Rochester, and leader of the team that found the star. "We were trying a new method of planet hunting and instead of finding a planet orbiting Alcor, we found a star."

Mamajek says that a separate group of scientists, led by Ben Oppenheimer of the American Natural History Museum, has also just found that the Alcor companion is physically associated with the star.

That group has also recorded a rough spectrum of the star, which Mamajek says confirms his prediction that the companion is a cool and dim M-class dwarf star.

Mamajek and colleagues at the University of Arizona used the Multiple Mirror Telescope in Arizona, which has a secondary mirror capable of flexing slightly to compensate for the twinkling the Earth's atmosphere normally imparts to starlight. With the clearest images he could obtain of nearby stars, Mamajek's team used computer algorithms to remove as much glare as possible from the image of a star in the hopes of spotting a planet near the star. Planets are so much dimmer than their parent stars that spotting one is like trying to discern a firefly next to a spotlight from several miles away, says Mamajek.

Though Mamajek was unable to find any planets in the first group of stars he surveyed, he did stumble across the tiny star hidden in the glare of Alcor. Not only did Mamajek's project reveal the image of the star, but its presence was able to explain slight deviations in movement that scientists had noticed in Alcor. In addition, Mamajek estimates that the small companion star is likely a third as massive as our sun, and explains why astronomers have detected unexpectedly high levels of X-rays coming from Alcor -- dwarf stars naturally radiate high levels of X-rays.

"It's pretty exciting to have found a companion to this particular star," says Mamajek. "Alcor and Mizar weren't just the first known binaries -- the four stars that were once thought to be the single Mizar were discovered in lots of 'firsts' throughout history."

Benedetto Castelli, Galileo's protege and collaborator, first observed with a telescope that Mizar was not a single star in 1617, and Galileo observed it a week after hearing about this from Castelli, and noted it in his notebooks, says Mamajek. Those two stars, called Mizar A and Mizar B, together with Alcor, in 1857 became the first binary stars ever photographed through a telescope. In 1890, Mizar A was discovered to itself be a binary, being the first binary to be discovered using spectroscopy. In 1908, spectroscopy revealed that Mizar B was also a pair of stars, making the group the first-known quintuple star system.

Mamajek says some astronomers have raised the question of whether Alcor is truly a part of the system made up of the Mizar group of stars because Alcor's motion isn't what scientists would expect it to be if it were gravitationally connected to the Mizar group. Mamajek says that indeed Alcor is part of the same system, and that the influence of Alcor's newly discovered companion is partly responsible for Alcor's unexpected motion.

Mamajek is continuing his efforts to find planets around nearby stars, but his attention is not completely off Alcor and Mizar. "You see how the disk of Alcor B doesn't seem perfectly round?" says Mamajek, pointing toward an image of Alcor and its new companion. "Some of us have a feeling that Alcor might actually have another surprise in store for us."

Since 1985, seawater temperature in Kuwait Bay, northern Persian Gulf, has increased on average 0.6°C per decade. This is about three times faster than the global average rate reported by the Intergovernmental Panel on Climate Change (IPCC). Differences are due to regional and local effects. Increased temperatures are having profound effects on key habitats and on power generation the Persian Gulf.

Researcher Dr Thamer Al-Rashidi of the National Oceanography Centre, Southampton, said: "Because the waters of Kuwait Bay are well mixed by the tides, measurements of sea surface temperature can be used to assess temperature trends over time in the bay as a whole."

He and his colleagues used data on sea surface temperature (1985-2007) remotely sensed by a number of polar orbiting satellites to assess warming in Kuwait Bay and the Gulf region.

The data were 'ground truthed' by direct measurements of sea surface temperature in the region, and are in accord with air temperature trends recorded at Kuwait airport, and verify trends found in satellite data.

They found that the sea surface temperature of Kuwait Bay increased over the period at an average rate of around 0.62°C per decade, with an uncertainty of plus or minus 0.01°C. This is about three times the rate of average global increase estimated by the IPCC.

The increase was greatest in the early summer and least during winter months. The length of summertime increased almost twice as fast as peak summertime temperature. In 1998 and 2003, the monthly measurements of sea surface temperature showed unusually high peaks in summer temperature coincident with El Niño events -- periodic warming of the atmosphere and ocean affecting weather in many parts of the world.

Temperature dipped in 1991, in the aftermath of the Iraqi invasion of Kuwait. "Dense smoke from the burning of oil fields hung over the region blocking out the sun, and we believe that this atmospheric dimming caused the relatively low summertime temperature peak recorded that year," said Dr Al-Rashidi, himself an officer in the Kuwaiti Navy. However, temperature then increased fairly steadily between 1992 and 2004.

"What all of this tells us," says Dr Al-Rashidi, "is that the global trends reported by the IPCC may not be representative locally."

The researchers estimate that about a third (0.2°C) of the observed decadal increase in seawater temperature in Kuwait Bay can be attributed to global climate change, while around 13 per cent of the increase (0.08°C) is due to human activity along the coast of the bay, especially the direct impacts of power and desalination plants.

The remaining 0.3°C (50 per cent) of decadal warming appears to be due to changes in regional drivers, including circulation and mixing of seawater in the Persian Gulf, the influence of the dominant north-westerly wind (Shamal), freshwater discharge from the Euphrates and Tigris rivers, and sand storms.

Increased seawater temperatures are likely responsible, at least in part, for the reduction in dissolved oxygen causing summertime fish kills, and also for coral bleaching in the region. In general, the researchers warn that increased temperatures may lead to serious environmental degradation in the sensitive marine ecosystems of the Persian Gulf.

Dr Al-Rashidi argues that regional warming could also have strategic implications: "Kuwait is dependent on desalination plants for its fresh water, and at temperatures over 37-38°C the turbines generating the electricity driving these plants have to be turned off," he said.

However, there have been distinct reductions in temperature since 2004 due to dust storms and their effect solar dimming. The frequency of dust storms has increased in recent years due to decreasing rainfall and increasing desertification. How this will interact with other local, regional and global factors to affect average temperatures in the long term remains uncertain.

"The lesson learnt is that temperature trends that we experience may be quite different from place to place due to variations in local and regional effects," said Dr Al-Rashidi.

An international team of environmental scientists led by the University of Pennsylvania has shown that sea-level rise along the Atlantic Coast of the United States was 2 millimeters faster in the 20th century than at any time in the past 4,000 years.

Sea-level rise prior to the 20th century is attributed to coastal subsidence. Put simply, land is being lost to subsidence as the earth continues to rise in response to the removal of the huge weight of ice sheets during the last glacial period. Using sediment cores from the U.S. Atlantic coast, researchers found significant spatial variations in land movement, with the mid-Atlantic coastlines of New Jersey, Delaware and Maryland subsiding twice as much as areas to the north and south. Coastal subsidence enhances sea-level rise, which leads to shoreline erosion and loss of wetlands and threatens coastal populations.

Researchers corrected relative sea-level data from tide gauges using the coastal-subsidence values. Results clearly show that the 20th-century rate of sea-level rise is 2 millimeters higher than the background rate of the past 4,000 years. Furthermore, the magnitude of the sea-level rise increases in a southerly direction from Maine to South Carolina. This is the first demonstrated evidence of this phenomenon from observational data alone. Researchers believe this may be related to the melting of the Greenland Ice Sheet and ocean thermal expansion.

"There is universal agreement that sea level will rise as a result of global warming but by how much, when and where it will have the most effect is unclear," said Benjamin P. Horton, assistant professor in the Department of Earth and Environmental Science at Penn. "Such information is vital to governments, commerce and the general public. An essential prerequisite for accurate prediction is understanding how sea level has responded to past climate changes and how these were influenced by geological events such as land movements."

The study provides the first accurate dataset for sea-level rise for the U.S. Atlantic coast, identifying regional differences that arise from variations in subsidence and demonstrate the possible effects of ice-sheet melting and thermal expansion for sea level rise.

The results appear in the Dec. 1 issue of the journal Geology. The study was supported by the National Science Foundation, the Thouron Family and the University of Pennsylvania.

Did the first dinosaurs wander across continents or stay put where they first evolved? The first dinosaurs evolved 230 million years ago when the continents were assembled into one landmass called Pangea. The question of early dinosaur movements remained unclear until the discovery of some exciting new fossils.

In the Dec. 11, 2009, issue ofScience, a team of paleontologists presents the 213-million-year-old fossils of previously unknown carnivorous dinosaur Tawa hallae,including several of the best preserved dinosaur skeletons from the Triassic Period.

Fossil bones of Tawa, named after the Hopi word for the Puebloan sun god, were recovered from a dig site in northern New Mexico known as Hayden Quarry. The quarry is located on Ghost Ranch, where late painter Georgia O'Keefe once lived. Fossil bones of several individuals were recovered, but the type specimen is a nearly complete skeleton of a juvenile that stood about 28 inches (70 centimeters) tall at the hips and was approximately 6 feet (about 2 meters) long, from snout to tail. Its body was about the size of a large dog, but with a much longer tail.

Based on an analysis of the relationships among Tawa and other early dinosaurs, the researchers hypothesize that dinosaurs originated in a part of Pangea that is now South America, diverging into theropods (like Tyrannosaurus rex), sauropodomorphs (like Apatosaurus) and ornithischians (like Triceratops); and then dispersed more than 220 million years ago across parts of Pangea that later became separate continents.

"This new dinosaur Tawa hallae changes our understanding of the relationships of early dinosaurs, and provides fantastic insight into the evolution of the skeleton of the first carnivorous dinosaurs" said Randall Irmis of the Utah Museum of Natural History and University of Utah, a co-author of the study.

In addition to Irmis, authors of the study included lead author Sterling Nesbit of the University of Texas at Austin; Nathan Smith of the University of Chicago and the Field Museum of Natural History; Alan Turner of Stony Brook University; Alex Downs of the Ruth Hall Museum of Paleontology in Abiquiu, N.M.; and Mark Norell of the American Museum of Natural History.

"If you have continents splitting apart, you get isolation," said Nesbitt. "So when barriers develop, you would expect that multiple carnivorous dinosaurs in a region should represent a closely related endemic radiation. But that is what we don't see in early dinosaur evolution."

Instead, the research team found three distinct carnivorous dinosaurs -- including the newly discovered Tawa -- in the fossil-rich, Late Triassic beds they investigated at Ghost Ranch. "When we analyzed the evolutionary relationships of these dinosaurs, we discovered that they were only distantly related, and that each species had close relatives in South America," said Irmis. "This implies that each carnivorous dinosaur species descended from a separate lineage before arriving in [the part of Pangea that is now] North America, instead of all evolving from a local ancestor."

At Ghost Ranch, the researchers found fossils from a carnivorous dinosaur related to Coelophysis, common to that region, and fossils from a carnivore closely related to Herrerasaurus, which lived in South America. The 6.6- to 13-foot-long (2- to 4-meter-long) skeletons of Tawa display characteristics that exist in both species and features found in neither, implying a separate lineage.

"The discovery of multiple dinosaur species in one place that emigrated from elsewhere got us wondering whether other Late Triassic reptiles show similar patterns" said Irmis. "It turns out a variety of other reptile groups made multiple trips from the northern and southern continents [then parts of Pangea] and back again during the Late Triassic, including other dinosaurs."

Because so many different groups with different life modes were able to move freely across Pangea, the research team concluded that during the Late Triassic, there were no major physical barriers, such as large mountain ranges, to the movement of reptiles between parts of Pangea that later separated into distinct continents.

But this presented a paradox to the team: "We wondered: if reptiles, including dinosaurs, were able to freely move around Pangea during the Late Triassic, then why aren't there any sauropodomorph and ornithischian dinosaurs in North America during the Triassic?" said Irmis. "Our conclusion is that climate, possibly related to latitude, controlled the distributions of some reptile species."

"We think that all the major dinosaur groups had the ability to get to North America [part of Pangea] during the Late Triassic, and may have even passed through, but for some reason, only the carnivorous dinosaurs found the North American climate to be hospitable during this time," concluded Irmis.

The first Tawa fossils were discovered in 2004 by volunteers taking a paleontology seminar at the Ruth Hall Museum of Paleontology in New Mexico. Museum scientists invited the team of paleontologists to come and take a look.

"The specimens are unusual because they are so well preserved," said Irmis. "Because dinosaur bones are hollow, they are usually broken and crushed, but those of Tawa are nearly pristine."

Irmis and the rest of the team began a full-scale excavation in 2006 and have continued to unearth new material every summer since then. The fossil bone bed extends for tens of yards along a hillside, promising many years of potential significant finds.