Heavens

TORONTO, ON – A University of Toronto-led team of astronomers has discovered over two dozen new free-floating brown dwarfs, including a lightweight youngster only about six times heftier than Jupiter, that reside in two young star clusters. What's more, one cluster contains a surprising surplus of them, harbouring half as many of these astronomical oddballs as normal stars.

The scope and intensity of mercury pollution in the Great Lakes region is much greater than previously reported, but additional mercury controls should bring needed improvement, according to a new summary of scientific research on the subject.

In the Crab Nebula, in the constellation Taurus, a remnant of an exploded star has astrophysicists scratching their heads, reassessing their theories about gamma rays — the highest-energy form of light, generated by subatomic particles moving close to the speed of light.

Astrophysicists have found evidence of black holes destroying stars, a long-sought phenomenon that provides a new window into general relativity. The research, reported in the latest issue of the Astrophysical Journal, also opens up a method to search for the possible existence of a large population of presently undetectable "intermediate mass" black holes which are hypothesized to be precursors to the super-massive black holes at the centers of most large galaxies.

CHAPEL HILL, N.C. – An estimated 1.3 million people in the United States suffer from rheumatoid arthritis. The causes behind this chronic disease — which can exhibit itself as pain, swelling, stiffness, deformation, and loss of function in the joints — have eluded scientists for centuries. A new study by UNC researchers offers tantalizing glimmers about the roles of a gene called CCR2, an immune system cell called Th17 cell, and a missing monocyte.

A thousand years ago, a brilliant beacon of light blazed in the sky, shining brightly enough to be seen even in daytime for almost a month. Native American and Chinese observers recorded the eye-catching event. We now know that they witnessed an exploding star, which left behind a gaseous remnant known as the Crab Nebula.

The largest survey to date of distant exploding stars is giving astronomers new clues to what's behind the Type Ia supernovae they use to measure distances across the cosmos.

Boulder, CO, USA - Space is a violent place. If a star explodes or black holes collide anywhere in our part of the Milky Way, they'd give off colossal blasts of lethal gamma-rays, X-rays and cosmic rays and it's perfectly reasonable to expect Earth to be bathed in them. A new study of such events has yielded some new information about the potential effects of what are called "short-hard" interstellar radiation events.

Most people know that some planets have moons but would be surprised to know that some asteroids do, too. According to Joshua Emery, assistant professor of earth and planetary sciences at the University of Tennessee, Knoxville, about 20 percent of them do.

Emery is part of an international team of planetary astronomers, led by Franck Marchis of the Carl Sagan Center of the SETI Institute in Mountain View, Calif., searching for moons around asteroids. The discovery of moons around asteroids is important because it can provide clues to the asteroid's formation.

In a painstaking re-analysis of Hubble Space Telescope images from 1998, astronomers have found visual evidence for two extrasolar planets that went undetected back then.

Finding these hidden gems in the Hubble archive gives astronomers an invaluable time machine for comparing much earlier planet orbital motion data to more recent observations. It also demonstrates a novel approach for planet hunting in archival Hubble data.

The tropics in the eastern Pacific were quiet for a couple of days after Hurricane Hilary dissipated, and today gave birth to Tropical Depression 10 and Tropical Storm Irwin. NASA's Aqua satellite captured an infrared image of both storms and saw the powerful convection in the center of Irwin that enabled the storm to go from a depression to a tropical storm in a short time.

Tropical Storm Philippe took its time to strengthen into a hurricane because of wind shear problems. The wind shear lessened, and Philippe became a hurricane today, after 12 days of moving across the Atlantic Ocean. NASA's TRMM satellite saw towering thunderstorms and intense rainfall within Philippe yesterday, which provided forecasters with a clue that the storm was strengthening. Philippe reached hurricane status this morning, Oct. 6, 2011.

An international collaboration of astrophysicists, including a group from the Department of Physics in Arts & Sciences at Washington University in St. Louis, has detected pulsed gamma rays from the neutron star at the heart of the Crab Nebula with energies far higher than the common theoretical models can explain.

An international team of scientists has detected the highest energy gamma rays ever observed from a pulsar, a highly magnetized and rapidly spinning neutron star.

The VERITAS experiment measured gamma rays coming from the Crab Pulsar at such large energies that they cannot be explained by current scientific models of how pulsars behave, the researchers said.

AMES, Iowa -- Iowa State University astrophysicists are part of an international team that unexpectedly discovered very-high-energy gamma rays from the already well-known Crab pulsar star.

The team's findings are published in the Oct. 7 issue of the journal Science.

"This is the first time very-high-energy gamma rays have been detected from a pulsar - a rapidly spinning neutron star about the size of the city of Ames but with a mass greater than that of the sun," said Frank Krennrich, an Iowa State professor of physics and astronomy and a co-author of the paper.