European Association for Astronomy Education

Source: NASA Science Casts

NASA's Fermi Gamma-ray Space Telescope is finding hundreds of new objects at the very edge of the electromagnetic spectrum. Many of them have one thing in common: Astronomers have no idea what they are.

Source: NASA Fermi

New sources emerge and old sources fade as the LAT's view extends into higher energies.
Credit: NASA/DOE/Fermi LAT Collaboration and A. Neronov et al.

After more than three years in space, NASA's Fermi Gamma-ray Space Telescope is extending its view of the high-energy sky into a largely unexplored electromagnetic range. Today, the Fermi team announced its first census of energy sources in this new realm.

Fermi's Large Area Telescope (LAT) scans the entire sky every three hours, continually deepening its portrait of the sky in gamma rays, the most energetic form of light. While the energy of visible light falls between about 2 and 3 electron volts, the LAT detects gamma rays with energies ranging from 20 million to more than 300 billion electron volts (GeV).

At higher energies, gamma rays are rare. Above 10 GeV, even Fermi's LAT detects only one gamma ray every four months. (read more)

Source: NASA Science Cast

In three years, NASA's Fermi has detected more than 100 gamma-ray pulsars, but something new has appeared. Among a type of pulsar with ages typically numbering a billion years or more, Fermi has found one that appears to have been born only millions of years ago.

Source: NASA Fermi

Image credits:NASA/DOE/Fermi LAT Collaboration.

An international team of scientists using NASA's Fermi Gamma-ray Space Telescope has discovered a surprisingly powerful millisecond pulsar that challenges existing theories about how these objects form.

At the same time, another team has located nine new gamma-ray pulsars in Fermi data, using improved analytical techniques.(read more)

Source: NASA Science News

The Fermi Gamma-ray Space Telescope recently produced a map of the night sky. Out of 1873 new sources, nearly 600 were complete mysteries. In today's story from Science@NASA, researchers speculate on the nature of the mystery objects--including the possibility that they are made of dark matter.(read more)

You tube video of the story:

Source: Physics World

New results from NASA's Fermi Gamma-Ray Space Telescope appear to confirm a larger-than-expected rate of high-energy positrons reaching the Earth from outer space. This anomaly in the cosmic-ray flux was first observed by the Italian-led PAMELA spacecraft in 2008 and suggests the existence of annihilating dark-matter particles. (read more)

Source: NASA-Fermi

The famous Crab Nebula supernova remnant has erupted in an enormous flare five times more powerful than any flare previously seen from the object. On April 12, NASA's Fermi Gamma-ray Space Telescope first detected the outburst, which lasted six days.

The nebula is the wreckage of an exploded star that emitted light which reached Earth in the year 1054. It is located 6500 light-years away in the constellation Taurus. At the heart of an expanding gas cloud lies what is left of the original star's core, a superdense neutron star that spins 30 times a second. With each rotation, the star swings intense beams of radiation toward Earth, creating the pulsed emission characteristic of spinning neutron stars (also known as pulsars).

Apart from these pulses, astrophysicists believed the Crab Nebula was a virtually constant source of high-energy radiation. But in January, scientists associated with several orbiting observatories, including NASA's Fermi, Swift and Rossi X-ray Timing Explorer, reported long-term brightness changes at X-ray energies. (read more)

Source: NASA Science News

An artist's concept of antimatter spraying above a thunderhead.
Image credit:NASA

At any given moment, about 1800 thunderstorms are in progress somewhere around the globe. New observations by the Fermi Gamma-ray Space Telescope show that many of these thunderstorms may be making antimatter.(read more)