When humanity sends spacecraft beyond our solar system, those starships will have to know exactly where they are at all times. A newly proposed cosmic GPS system can track a spacecraft’s location to within five kilometers anywhere in the galaxy.
The secrets to this system are pulsars, a special type of neutron star that rotate at short, extremely regular intervals. That last bit is crucial - because we can count on pulsars to always rotate at the exact same speed, which makes them useful timekeepers across even the vast reaches of space. Indeed, some pulsars that rotate every few milliseconds are actually comparable to atomic clocks in terms of precision and dependability.
Posts tagged "pulsar"
Imaged Above: The slow-spinning X-ray pulsar SXP 1062 shines brightly from within the shell of gas and dust rushing away from the supernova that formed it. Image Credit: ESA/XMM-Newton/ L.Oskinova/ M.Guerrero; CTIO/R.Gruendl/Y.H.Chu
Astronomers have discovered a strange spinning star that appears to be older than the explosion that gave birth to it, scientists say.
The star is a pulsar, a rotating, super-dense core left behind after a massive star goes supernova. This pulsar, known as SXP 1062, is spinning quite slowly, suggesting an advanced age.
But the pulsar can’t be as old as it looks, because the star probably exploded less than 40,000 years ago, researchers said. They’ve just now begun delving into this newly discovered cosmic mystery.
(via 2voyager)Source space.com
The Crab Pulsar, a city-sized, magnetized neutron star spinning 30 times a second, lies at the center of this composite image of the inner region of the well-known Crab Nebula.Source apod.nasa.gov
Fermi finds super-energetic millisecond pulsar
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.
credit: astronomy.comSource the-star-stuff
When astronomers detected intense radiation pumping out of the Crab Nebula, one of the most studied objects in space, at higher energies than anyone thought possible, they were nothing short of stunned.
The inexplicably powerful gamma-rays came from the very heart of the Crab Nebula, where an extreme object called a pulsar resides.
“It was totally not expected — it was absolutely jaw-dropping,” Andrew McCann, a Ph.D. candidate at McGill University in Montreal, Canada, and a co-author of the new study, told SPACE.com. “This is one of the hottest targets in the sky, so people have been looking at the Crab Nebula for a long time. Now there’s a twist in the tale. High-energy rays coming from the nebula are well-known, but coming from the pulsar is something nobody expected.”Source space.com
What Is A Pulsar?
Pulsars are the products of colossal star explosions. When a star about ten times the size of our Sun dies, it undergoes an ejection of its “mantle” in a great supernova explosion, leaving the highly magnetized and compressed nucleus of the star behind. The nucleus left behind may become what you see above—a pulsar; a rotating neutron star.
Although pulsars are only about the size of a city, pulsars are incredibly dense, possibly having as much material as our Sun. Pulsars don’t actually “pulse”, rather, they appear to pulse due to what is known as the “lighthouse effect”. Huge beams of radiation are ejected from the magnetic axis of the pulsar. These glaring emissions are only visible to us when they are pointed straight at the earth, giving the pulsar an appearance of pulsation.
One of the most impressive facts about pulsars is that, because of their incredible density, their rotational periods are extremely swift and extremely precise. Most pulsar rotational periods are anywhere from a few seconds to a few milliseconds!
(via likeaphysicist)Source cosmo-logic
A Pulsar is a small star made up of neutrons so densely packed together that if one the size of a silver dollar landed on earth, it would weigh approximately 100 million tons.