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Spitzer observes echo of neutron star outburst UNIVERSITY OF ARIZONA NEWS RELEASE Posted: June 9, 2005 Astronomers observing with NASA's Spitzer Space Telescope say they may have seen the infrared "echo" of a neutron star that sent a blast wave from inside supernova remnant Cassiopeia A about 50 years ago.
Spitzer has taken two pictures, spaced a year apart, of the energized interstellar dust, glowing bright at 24 micron wavelengths but invisible at the shorter wavelengths our eyes see. The pictures show different glowing clumps. By comparing them, Krause and Rieke can estimate when the blast occurred and what caused it. NASA is releasing the stunning Spitzer images and animations today on the Spitzer Space Telescope Website, http://www.spitzer.caltech.edu/spitzer/. Krause, Rieke and their colleagues are reporting the discovery in the June 10 issue of Science. About 50 years ago, the neutron star appears to have shot tremendous energy in opposite directions, in paths roughly perpendicular to the direction toward Earth, Krause and Rieke said. Even if astronomers had been looking toward the Cas A supernova remnant a half century ago, they wouldn't have noticed the outburst because it was not directed toward Earth, they said. Cassiopeia A, the youngest supernova remnant known in our galaxy, exploded 325 years ago. Spitzer took images of Cas A and surrounding sky in November 2003 while checking out Spitzer's Multiband Imaging Photometer (MIPS), the instrument that Rieke and his team developed to scan the sky at very long infrared wavelengths. Bright, wispy filaments and knots stetched well beyond Cas A, across their entire image, which was slightly longer than the apparent diameter of Earth's moon. Followup near-infrared observations made at the 6.5-meter Multiple Mirror Telescope Observatory at Mount Hopkins, Ariz., in May 2004 and at the Calar Alto, Spain, 3.5-meter telescope in October 2004 and January 2005 showed some of the very brightest features were moving at close to the speed of light. The team used Spitzer to rescan Cas A in December 2004. Krause analyzed how the features had moved in a year's time, and the researchers realized that some of the infrared wisps and knots were at the wrong location to be ejecta from the supernova Cas A explosion itself 325 years ago. "Further measurements will test this, but we think that the neutron star within Cas A had an outburst about 50 years ago," Rieke said. "We see light that is just now encountering two interstellar clouds and heating them so we see the outburst's infrared echo." Krause, Rieke, others from UA Steward Observatory, the Max Planck Institute for Astronomy (Heidelberg), Rutgers University and Space Science Institute wrote the article being published in Science. JPL manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. JPL is a division of Caltech. The multi-band imaging photometer for Spitzer, which made the far infrared observations, was built by Ball Aerospace Corporation, Boulder, Colo.; The University of Arizona; and Boeing North American, Canoga Park, Calif. |
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As excitement builds for the first space shuttle launch in over two years, this comprehensive video selection captures the major pre-flight events for Discovery and her seven astronauts.
A camera on the International Space Station captured this view of Tropical Storm Arlene moving into the Gulf of Mexico as the orbiting complex flew above the weather system at 2:33 p.m. EDT on Friday, June 10. (3min 06sec file)
NASA's space-based research into how hurricanes form and move is explained in this narrated movie from the agency. (8min 02sec file)
Dr. Bonnie Buratti, team member of the Cassini visual and infrared mapping spectrometer, discusses a possible volcano discovered on Saturn's moon Titan. (2min 12sec file)
The co-chairs and other members of the Stafford-Covey Return to Flight Task Group, which is overseeing NASA's space shuttle program, hold a news conference in Houston on June 8.
Technicians ready space shuttle Discovery for demating from the external fuel tank inside the Vehicle Assembly Building. (1min 24sec file)
Space shuttle Discovery is demated from its original external fuel tank and solid rocket boosters. The ship is lowered to its transport trailer in the Vehicle Assembly Building. (2min 38sec file)
Shuttle Discovery enters into the Vehicle Assembly Building after a 10-hour journey from launch pad 39B. (4min 29sec file)
The International Space Station's Expedition 11 crew pays tribute to our fallen heroes for Memorial Day. (1min 00sec QuickTime file)
In the predawn hours, the Apollo-era crawler-transporter is driven beneath shuttle Discovery's mobile launch platform at pad 39B in preparation for the rollback to the Vehicle Assembly Building. (2min 37sec QuickTime file)
Workers disconnect a vast number of umbilicals running between launch pad 39B and Discovery's mobile launch platform for the rollback. The cabling route electrical power, data and communications to the shuttle. (2min 32sec file)
The crawler-transporter begins rolling space shuttle Discovery off launch pad 39B at 6:44 a.m. EDT May 26 for the 4.2-mile trip back to the Vehicle Assembly Building. (7min 28sec file)
This animation shows the Voyager spacecraft heading into the solar system's final frontier and the edge of interstellar space. (1min 24sec file)
