Spaceflight Now Home



Spaceflight Now +



Premium video content for our Spaceflight Now Plus subscribers.

Day of Remembrance
NASA pays tribute to those lost while furthering the cause of exploration, including the Apollo 1, Challenger and Columbia crews, during this Day of Remembrance memorial from agency headquarters on Jan. 27. (38min 58sec file)

 Play video:
   Dial-up | Broadband

 Download audio:
   For iPod

Shuttle's new inspector
The Orbiter Boom Sensor System is loaded into space shuttle Discovery's payload bay. The arm will be used to inspect the shuttle for damage following the return-to-flight launch. (4min 18sec file)
 Play video

Spacewalk highlights
The Expedition 10 conducts a successful spacewalk outside the International Space Station to mount a German robotic arm and Russian science package to the Zvezda service module's exterior. (5min 07sec file)
 Play video

Huygens science update
One week after the Huygens probe landed on Saturn's moon Titan, scientists hold a news conference to announce additional results and describe more pictures from the mission. (69min 02sec file)

 Play video:
   Dial-up | Broadband

ISS spacewalk preview
The upcoming spacewalk by the International Space Station's Expedition 10 crew is previewed by NASA officials at the Johnson Space Center on Jan. 21. (25min 04sec file)

 Play video:
   Dial-up | Broadband

Launch of Deep Impact!
A Boeing Delta 2 rocket blasts off from Cape Canaveral carrying NASA's comet-smashing probe called Deep Impact. This extended clip follows the mission through second stage ignition and jettison of the rocket's nose cone. (5min 37sec file)
 Play video

Press Site view
A camera located at Cape Canaveral's Press Site 1 location offers this view of the Delta rocket's ascent. (1min 24sec file)
 Play video

Become a subscriber
More video



NewsAlert



Sign up for our NewsAlert service and have the latest news in astronomy and space e-mailed direct to your desktop.

Enter your e-mail address:

Privacy note: your e-mail address will not be used for any other purpose.



Biggest stars produce strongest magnets
HARVARD-SMITHSONIAN CENTER FOR ASTROPHYSICS NEWS RELEASE
Posted: January 28, 2005

Astronomy is a science of extremes - the biggest, the hottest, and the most massive. Today, astrophysicist Bryan Gaensler (Harvard-Smithsonian Center for Astrophysics) and colleagues announced that they have linked two of astronomy's extremes, showing that some of the biggest stars in the cosmos become the strongest magnets when they die.

"The source of these very powerful magnetic objects has been a mystery since the first one was discovered in 1998. Now, we think we have solved that mystery," says Gaensler.

The astronomers base their conclusions on data taken with CSIRO's Australia Telescope Compact Array and Parkes radio telescope in eastern Australia.

A magnetar is an exotic kind of neutron star--a city-sized ball of neutrons created when a massive star's core collapses at the end of its lifetime. A magnetar typically possesses a magnetic field more than one quadrillion times (one followed by 15 zeroes) stronger than the earth's magnetic field. If a magnetar were located halfway to the moon, it could wipe the data from every credit card on earth.

Magnetars spit out bursts of high-energy X-rays or gamma rays. Normal pulsars emit beams of low-energy radio waves. Only about 10 magnetars are known, while astronomers have found more than 1500 pulsars.

"Both radio pulsars and magnetars tend to be found in the same regions of the Milky Way, in areas where stars have recently exploded as supernovae," explains Gaensler. "The question has been: if they are located in similar places and are born in similar ways, then why are they so different?"

Previous research has hinted that the mass of the original, progenitor star might be the key. Recent papers by Eikenberry et al (2004) and Figer et al (2005) have suggested this connection, based on finding magnetars in clusters of massive stars.

"Astronomers used to think that really massive stars formed black holes when they died," says Dr Simon Johnston (CSIRO Australia Telescope National Facility). "But in the past few years we've realized that some of these stars could form pulsars, because they go on a rapid weight-loss program before they explode as supernovae."

These stars lose a lot of mass by blowing it off in winds that are like the sun's solar wind, but much stronger. This loss would allow a very massive star to form a pulsar when it died.

To test this idea, Gaensler and his team investigated a magnetar called 1E 1048.1-5937, located approximately 9,000 light-years away in the constellation Carina. For clues about the original star, they studied the hydrogen gas lying around the magnetar, using data gathered by CSIRO's Australia Telescope Compact Array radio telescope and its 64-m Parkes radio telescope.

By analyzing a map of neutral hydrogen gas, the team located a striking hole surrounding the magnetar. "The evidence points to this hole being a bubble carved out by the wind that flowed from the original star," says Naomi McClure-Griffiths (CSIRO Australia Telescope National Facility), one of the researchers who made the map. The characteristics of the hole indicate that the progenitor star must have been about 30 to 40 times the mass of the sun.

Another clue to the pulsar/magnetar difference may lie in how fast neutron stars are spinning when they form. Gaensler and his team suggest that heavy stars will form neutron stars spinning at up to 500-1000 times per second. Such rapid rotation should power a dynamo and generate superstrong magnetic fields. 'Normal' neutron stars are born spinning at only 50-100 times per second, preventing the dynamo from working and leaving them with a magnetic field 1000 times weaker, says Gaensler.

"A magnetar goes through a cosmic extreme makeover and ends up very different from its less exotic radio pulsar cousins," he says.

If magnetars are indeed born from massive stars, then one can predict what their birth rate should be, compared to that of radio pulsars.

"Magnetars are the rare 'white tigers' of stellar astrophysics," says Gaensler. "We estimate that the magnetar birth rate will be only about a tenth that of normal pulsars. Since magnetars are also short-lived, the ten we have already discovered may be almost all that are out there to be found."

This press release is being issued in conjunction with CSIRO's Australia Telescope National Facility.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

Ares 1-X Patch
The official embroidered patch for the Ares 1-X rocket test flight, is available for purchase.
 U.S. STORE
 WORLDWIDE STORE

Apollo Collage
This beautiful one piece set features the Apollo program emblem surrounded by the individual mission logos.
 U.S. STORE

Expedition 21
The official embroidered patch for the International Space Station Expedition 21 crew is now available from our stores.
 U.S. STORE
 WORLDWIDE STORE

Hubble Patch
The official embroidered patch for mission STS-125, the space shuttle's last planned service call to the Hubble Space Telescope, is available for purchase.
 U.S. STORE
 WORLDWIDE STORE

INDEX | PLUS | NEWS ARCHIVE | LAUNCH SCHEDULE
ASTRONOMY NOW | STORE

ADVERTISE

© 2014 Spaceflight Now Inc.