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Astronomers find new kind of cosmic object CSIRO NEWS RELEASE Posted: February 15, 2006
The new objects - dubbed Rotating Radio Transients or RRATs - are likely to be related to conventional radio pulsars (small stars that emit regular pulses of radio waves, up to hundreds of times a second). But the new objects probably far outnumber their old cousins, the scientists say. Eleven RRATs have been found, first detected by the Parkes Multibeam Pulsar Survey and then observed again several times. Their isolated bursts last for between two and 30 milliseconds. In between, for times ranging from four minutes to three hours, they are silent. "These things were very difficult to pin down," says CSIRO's Dr Dick Manchester, a member of the research team and a veteran pulsar hunter. "For each object we've been detecting radio emission for less than one second a day. And because these are single bursts, we've had to take great care to distinguish them from terrestrial radio interference." By analysing the burst arrival times, the astronomers have found that 10 of the 11 sources have underlying periods of between 0.4 seconds and seven seconds. It is this that suggests that they are rotating neutron stars. Because RRATs are 'silent' most of the time, the chance of being able to detect one is low. Many more must lurk unseen in our Galaxy, the astronomers argue - perhaps a few hundred thousand. The number of 'normal' radio pulsars in our Galaxy is estimated to be about 100 000. Unlike some other kinds of stars that show periodic eruptions, the RRATs show no evidence for being in binary systems (that is, each orbiting another star). A handful of 'normal' pulsars produce the occasional 'giant' pulse, along with their usual train of regular, smaller pulses. The RRATs appear to differ from these pulsars by having magnetic field strengths in the emission region about a hundred thousand times weaker. |
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  SFN+Plus Video clip of the day  STS-5: With the four test flights complete, NASA declared the space shuttle a fully operational program. The crews were expanded, commercial payloads were welcomed aboard and the mission plans became much more hectic. This new era began with Columbia's STS-5 flight that launched the ANIK-C3 and SBS-C commercial communications satellites from the shuttle's payload bay. Commander Vance Brand, pilot Bob Overmyer and mission specialists Joe Allen and Bill Lenoir narrate highlights from their November 1982 mission in this post-flight presentation.  PLAY VIDEOHOW DO I SIGN UP? Spaceflight Now is pleased to present our new Mission Report Minute video podcast, a free service to bring you the latest news from the space program in a short one-minute bulletin!SUBSCRIBE ON iTUNES (free)Columbia Report  A reproduction of the official accident investigation report into the loss of the space shuttle Columbia and its crew of seven. Choose your store:U.S. - U.K. - E.U. - Worldwide |
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INDEX | PLUS | NEWS ARCHIVE | LAUNCH SCHEDULE MISSION REPORT | ASTRONOMY NOW | STORE ADVERTISE � 2006 Pole Star Publications Ltd |
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The
developmental test flights of the space shuttle concluded with
Columbia's STS-4 mission. Commander Ken Mattingly and pilot Henry
Hartsfield spent a week in space examining orbiter systems and running
science experiments. The 1982 flight ended on the Fourth of July with
President Reagan at the landing site to witness Columbia's return and
the new orbiter Challenger leaving for Kennedy Space Center. Watch this
STS-4 post-flight crew presentation film.
Columbia's
STS-3 mission is best remembered in the history books for its
conclusion -- the first and so far only landing at the picturesque
Northrup Strip at White Sands, New Mexico. In this post-flight
presentation film, the crew describes the highlights of the March 1982
mission and shows some of the fun they had in orbit. The commander also
tells how he accidentally "popped a wheelie" before bringing the nose
gear down to the runway surface.
Seven
months after the successful maiden voyage of space shuttle Columbia,
astronauts Joe Engle and Richard Truly took the orbiter back into space
on mission STS-2. The November 12, 1981 launch demonstrated that the
space shuttle was the world's first reusable manned spacecraft.
Although their mission would be cut short, Engle and Truly performed
the first tests of the shuttle's Canadian-made robotic arm. The crew
tells the story of the mission in this post-flight presentation.
The
space shuttle era was born on April 12, 1981 when astronauts John Young
and Bob Crippen rode Columbia into Earth orbit from Kennedy Space
Center's launch pad 39A. The two-day flight proved the shuttle could
get into space as a rocket and return safely with a runway landing.
Following the voyage of STS-1, the two astronauts narrated this film of
the mission highlights and told some of their personal thoughts on the
flight.
The
Expedition 12 crew tosses overboard an old Russian spacesuit loaded
with ham radio gear during a spacewalk outside the International Space
Station. The eery view of the lifeless suit tumbling into the darkness
of space was captured by station cameras.