Brightsurf Science News and Current Science News Events
 
Email a Friend Send to a friend
Printer Friendly Print Milky Way's fastest pulsar is on its way out of the galaxy, astronomers find

Milky Way's fastest pulsar is on its way out of the galaxy, astronomers find

February 16, 2006

The Milky Way's fastest observed pulsar is speeding out of the galaxy at more than 670 miles a second, propelled largely by a kick it received at its birth 2.5 million years ago.

Using the Very Long Baseline Array (VLBA), 10 radio telescopes spanning 5,000 miles from Hawaii to the U.S. Virgin Islands, James Cordes, professor of astronomy at Cornell University, his former student Shami Chatterjee, now of the Harvard-Smithsonian Center for Astrophysics, and colleagues studied the pulsar (a fast-spinning neutron star) B1508+55, about 7,700 light years from Earth. With the ultra-sharp radio vision of the continentwide VLBA, they precisely measured both the distance and the speed of the pulsar.




The team then plotted the star's motion backward to a birthplace among groups of giant stars in the constellation Cygnus, which contains stars so massive they inevitably explode as supernovae.

Commenting on the research, which was published last fall in Astrophysical Journal Letters, Chatterjee said, "We know that supernova explosions can give a kick to the resulting neutron star, but the tremendous speed of this object pushes the limits of our current understanding. This discovery is very difficult for the latest models to explain." Chatterjee is also a Jansky fellow at the National Radio Astronomy Observatory (NRAO).

The VLBA measurements show the pulsar moving at nearly 1,100 kilometers (more than 670 miles) per second. At this speed, it could travel from London to New York in five seconds.

To measure the pulsar's distance, the astronomers had to detect a very slight wobble in its position caused by the Earth's motion around the sun. This enabled them to calculate the pulsar's speed by measuring its motion across the sky.

"The motion we measured with the VLBA was about equal to watching a home run ball in Boston's Fenway Park from a seat on the moon," Chatterjee said. "However, the pulsar took nearly 22 months to show that much apparent motion. The VLBA is the best possible telescope for tracking such tiny apparent motions."

"The physics is not well understood because the high pulsar speed is the result of the implosion of the core of a star that took only a few seconds about 2.5 million years ago," said Cordes. "The reason this is so different is the precision of it. In astronomy one of the big problems is getting the distance scale. In the past we've identified objects whose velocity we've estimated, but what makes this special is there's no uncertainty in the distance. It's ironclad. There's no wiggle room. It gets rid of any question."

The star's presumed birthplace lies within the plane of the Milky Way, a spiral galaxy. The new VLBA observations indicate that the pulsar now is headed away from the Milky Way's plane with enough speed to leave the galaxy. Since the supernova explosion, the pulsar has moved across about a third of the night sky as seen from Earth.

"We've thought for some time that supernova explosions can give a kick to the resulting neutron star, but the latest computer models of this process have not produced speeds anywhere near what we see in this object," Chatterjee said. "This means that the models need to be checked, and possibly corrected, to account for our observations," he said, noting that other processes could be at work as well.

The observations were part of a larger project to use the VLBA to measure the distances and motions of pulsars. "This is the first result of this long-term project, and it's pretty exciting to have something so spectacular come this early," said NRAO's Walter Brisken, a co-author.

Each of the radio telescopes in the VLBA, which is funded by the National Science Foundation (NSF), has a dish 25 meters (82 feet) in diameter and weighs 240 tons. The VLBA provides astronomers with the sharpest vision of any telescope on Earth or in space.

Chatterjee is lead author of the Astrophysical Journal Letters article. Other co-authors include Joseph Lazio of the Naval Research Laboratory, Miller Goss and Edward Fomalont of NRAO, Stephen Thorsett of the University of California-Santa Cruz, and Andrew Lyne, Wouter Vlemmings and Michael Kramer of Jodrell Bank Observatory. The NRAO is a facility of NSF, operated under cooperative agreement by Associated Universities Inc.

Cornell University



Related Pulsar News Articles Pulsar News and Current Pulsar Events RSS Pulsar News and Current Pulsar Events RSS
GLAST Observatory renamed for Fermi, reveals entire gamma-ray sky
The U.S. Department of Energy (DOE) and NASA announced today that the Gamma-Ray Large Area Space Telescope (GLAST) has revealed its first all-sky map in gamma rays.

In Unique Stellar Laboratory, Einstein's Theory Passes Strict, New Test
Taking advantage of a unique cosmic configuration, astronomers have measured an effect predicted by Albert Einstein's theory of General Relativity in the extremely strong gravity of a pair of superdense neutron stars. Essentially, the famed physicist's 93-year-old theory passed yet another test.

LIGO observations probe the dynamics of the crab pulsar
The search for gravitational waves has revealed new information about the core of one of the most famous objects in the sky: the Crab Pulsar in the Crab Nebula.

Powerful explosions suggest neutron star missing link
Observations from NASA's Rossi X-ray Timing Explorer (RXTE) have revealed that the youngest known pulsing neutron star has thrown a temper tantrum.

Jekyll-Hyde neutron star discovered by researchers
Like something out of a Robert Louis Stevenson novel, researchers at NASA and McGill University discovered an otherwise normal pulsar which violently transformed itself temporarily into a magnetar, a stellar metamorphosis never observed before.

Neutron stars can be more massive, while black holes are more rare, Arecibo Observatory finds
Neutron stars and black holes aren't all they've been thought to be. In fact, neutron stars can be considerably more massive than previously believed, and it is more difficult to form black holes, according to new research developed by using the Arecibo Observatory in Arecibo, Puerto Rico.

White Dwarf Pulses Like a Pulsar
New observations from Suzaku, a joint Japanese Aerospace Exploration Agency (JAXA) and NASA X-ray observatory, have challenged scientists' conventional understanding of white dwarfs. Observers had believed white dwarfs were inert stellar corpses that slowly cool and fade away, but the new data tell a completely different story.

Stellar forensics with striking new image from Chandra
A spectacular new image shows how complex a star's afterlife can be. By studying the details of this image made from a long observation by NASA's Chandra X-ray Observatory, astronomers can better understand how some stars die and disperse elements like oxygen into the next generation of stars and planets.

Researchers using Arecibo Telescope discover never-before-seen pulsar blasts in Crab Nebula
Astronomers and physicists using the Cornell-managed Arecibo Telescope in Puerto Rico have discovered radio interpulses from the Crab Nebula pulsar that feature never-before-seen radio emission spectra. This leads scientists to speculate this could be the first cosmic object with a third magnetic pole.

Astronomers find first ever gamma ray clock
Astronomers using the H.E.S.S. telescopes have discovered the first ever modulated signal from space in Very High Energy Gamma Rays - the most energetic such signal ever observed.
More Pulsar News Articles


Card Making by Number: Everything You Need to Know Create 50 Cards
by Pulsar Eco Products LLC

Card making has quickly become one of today's hottest crafting mediums! This colorful, wire-bound book contains everything you will need to produce 50 beautiful cards. The book includes die-cuts, envelopes, an illustration leaflet and embellishment pack. The simple steps printed on each die-cut page illustrate exactly how to put the cards together, and the leaflet provides more in-depth...



Cosmological Enigmas: Pulsars, Quasars, and Other Deep-Space Questions
by Mark Kidger

The universe is big. Really big. And it gets bigger every day. In Cosmological Enigmas, Mark Kidger weaves together history, science, and science fiction to consider questions about the bigness of space and the strange objects that lie trembling at the edge of infinity. What are quasars, blazars, and gamma-ray bursters? Could we ever travel to the stars? Can we really expect aliens to contact us?...



Decoding the Message of the Pulsars: Intelligent Communication from the Galaxy
by Paul A. LaViolette

A new interpretation of nearly 40 years of interstellar signals and the prophetic message they contain• Contains extensive analysis of pulsar data, revealing new ideas about the origins and functions of pulsars• Provides proof of an extraterrestrial communication network• Includes information about the formation of crop circles and force-field-beaming technologyIn 1967,...



Blood of Heroes Role-Playing Game : Special Edition
by Joshua Marquart, Tony Oliviera, Christopher Tatro, Jonathan Cassie



Nissan: Sentra/Pulsar/NX 1982-96 (Chilton's Total Car Care Repair Manual)
by Chilton Editors

Total Car Care is the most complete, step-by-step automotive repair manual you'll ever use. All repair procedures are supported by detailed specifications, exploded views, and photographs. From the simplest repair procedure to the most complex, trust Chilton's Total Car Care...

Frozen Star
by George Greenstein

Black Holes, Pulsars, And Quasars (Isaac Asimov's 21st Century Library of the Universe)
by Isaac Asimov, Richard Hantula



Handbook of Pulsar Astronomy (Cambridge Observing Handbooks for Research Astronomers)
by D. R. Lorimer, M. Kramer

Radio pulsars are rapidly rotating, highly magnetized neutron stars. This comprehensive book brings together key observational techniques, background information and a review of the latest results, including the recent discovery of a double pulsar system. Useful software tools are provided to analyze example data, made available on a related website. The work will be of great value to graduate...

Neutron Stars and Pulsars (Astrophysics and Space Science Library)

Neutron stars are the most compact astronomical objects in the universe which are accessible by direct observation. Studying neutron stars means studying physics in regimes unattainable in any terrestrial laboratory. Understanding their observed complex phenomena requires a wide range of scientific disciplines, including the nuclear and condensed matter physics of very dense matter in neutron...



Clocks in the Sky: The Story of Pulsars (Springer Praxis Books / Popular Astronomy)
by Geoff McNamara

Pulsars are rapidly spinning neutron stars, the collapsed cores of once massive stars that ended their lives as supernova explosions. Pulsar rotation rates can reach incredible speeds, up to hundreds of times per second. The story of how an object ‘spins up’ to a significant fraction of the speed of light is fascinating and involves collapsing stellar cores following supernova...

© 2008 BrightSurf.com