Apparently, Toronto is going to be graced with some 3000 educational signs on Toronto Transit Commission vehicles.  The signs are both easy on the eyes and educational.  Check out CoolCosmos for more examples.

And while I am on the topic of supernovae, astronomers at the Chandra X-Ray observatory have just released a time lag video of the continued expansion of Cassiopeia A, a supernova remnant.  You can read all about it from Scientific Blogging's News Staff.
Astronomers say they may have solved one of those classic chicken-and-egg problems, namely, which came first in the early Universe, galaxies or the supermassive black holes seen at their cores.

Chris Carilli, of the National Radio Astronomy Observatory (NRAO), outlined the conclusions from recent research done by an international team studying conditions in the first billion years of the Universe's history in a lecture presented to the American Astronomical Society's meeting in Long Beach, California.
NASA's Fermi Gamma-ray Space Telescope has discovered 12 new gamma-ray-only pulsars and has detected gamma-ray pulses from 18 others. The finds are transforming our understanding of how these stellar cinders work.

"We know of 1,800 pulsars, but until Fermi we saw only little wisps of energy from all but a handful of them," says Roger Romani of Stanford University, Calif. "Now, for dozens of pulsars, we're seeing the actual power of these machines."

A pulsar is a rapidly spinning and highly magnetized neutron star, the crushed core left behind when a massive sun explodes. Most were found through their pulses at radio wavelengths, which are thought to be caused by narrow, lighthouse-like beams emanating from the star's magnetic poles.
Two new efforts have taken a famous supernova remnant from the static to the dynamic. A new movie of data from NASA's Chandra X-ray Observatory shows changes in time never seen before in this type of object. A separate team will also release a dramatic three-dimensional visualization of the same remnant.

Nearly ten years ago, Chandra's "First Light" image of Cassiopeia A (Cas A) revealed previously unseen structures and detail. Now, after eight years of observation, scientists have been able to construct a movie that tracks the remnant's expansion and changes over time.
We may not be using it for navigation any time soon, but a new map of our own Milky Way galaxy provides other answers about the structure of our galaxy, and resolves conflicting information gathered from previous surveys.

Many previous mappings of the Milky Way have focused on either the inner galaxy or the outer galaxy, and as a result, different surveys have found different numbers of spiral arms - two in the inner galaxy and four in the outer. Now, Iowa State University has completed the first map of the entire system of galactic spiral arms, which shows two arms at the center branching into four on the outside.
Let's face it, with all that talk about life on other planets and dark matter, we lose sight of the big picture.  To start 2009 off right, the Milky Way, our galaxy, wants you to know she is not out of coolness yet.  To wit, new measurements of the Milky Way say our home Galaxy is rotating about 100,000 miles per hour faster than previously thought.
Astronomers have turned to an unexpected place to study the evolution of planets -- dead stars. 

Observations made with NASA's Spitzer Space Telescope reveal six dead "white dwarf" stars littered with the remains of shredded asteroids. This might sound pretty bleak, but it turns out the chewed-up asteroids are teaching astronomers about the building materials of planets around other stars. 

So far, the results suggest that the same materials that make up Earth and our solar system's other rocky bodies could be common in the universe. If the materials are common, then rocky planets could be, too. 
Iowa State University's Martin Pohl is part of a research team that has developed the first complete map of the Milky Way galaxy's spiral arms.

The map shows the inner part of the Milky Way has two prominent, symmetric spiral arms, which extend into the outer galaxy where they branch into four spiral arms.

"For the first time these arms are mapped over the entire Milky Way," said Pohl, an Iowa State associate professor of physics and astronomy. "The branching of two of the arms may explain why previous studies – using mainly the inner or mainly the outer galaxy – have found conflicting numbers of spiral arms."
Smithsonian Center for Astrophysics astronomers examined the 5 million-year-old star cluster NGC 2362 with NASA's Spitzer Space Telescope, which can detect the signatures of actively forming planets in infrared light, and found that all stars with the mass of the Sun or greater have lost their protoplanetary (planet-forming) disks.

Only a few stars less massive than the Sun retain their protoplanetary disks. These disks provide the raw material for forming gas giants like Jupiter. Therefore, gas giants have to form in less than 5 million years or they probably won't form at all.

So baby Jupiter had to gain weight quickly. 

Brown dwarfs, objects that are less massive than stars but larger than planets, just got more elusive, based on a study of 233 nearby multiple-star systems by NASA's Hubble Space Telescope. Hubble found only two brown dwarfs as companions to normal stars. This means the so-called "brown dwarf desert" (the absence of brown dwarfs around solar-type stars) extends to the smallest stars in the universe.

The 233 stars surveyed are part of the RECONS (Research Consortium on Nearby Stars) survey meant to understand the nature of the sun's nearest stellar neighbors, both individually and as a population. The current primary goals are to discover and characterize "missing" members of the sample of stars within 32.6 light-years (10 parsecs) of Earth.