NASA News: NASA's Swift Finds a Gamma-Ray Burst With a Dual Personality
WASHINGTON -- A peculiar cosmic explosion first detected by NASA'sSwift observatory on Christmas Day 2010 was caused either by a novel
type of supernova located billions of light-years away or an unusual
collision much closer to home, within our own galaxy. Papers
describing both interpretations appear in the Dec. 1 issue of the
journal Nature.
Gamma-ray bursts (GRBs) are the universe's most luminous explosions,
emitting more energy in a few seconds than our sun will during its
entire energy-producing lifetime. What astronomers are calling the
"Christmas burst" is so unusual that it can be modeled in such
radically different ways.
"What the Christmas burst seems to be telling us is that the family of
gamma-ray bursts is more diverse than we fully appreciate," said
Christina Thoene, the supernova study's lead author, at the Institute
of Astrophysics of Andalusia in Granada, Spain. It's only by rapidly
detecting hundreds of them, as Swift is doing, that we can catch some
of the more eccentric siblings."
Common to both scenarios is the presence of a neutron star, the
crushed core that forms when a star many times the sun's mass
explodes. When the star's fuel is exhausted, it collapses under its
own weight, compressing its core so much that about a half-million
times Earth's mass is squeezed into a sphere no larger than a city.
The Christmas burst, also known as GRB 101225A, was discovered in the
constellation Andromeda by Swift's Burst Alert Telescope at 1:38 p.m.
EST on Dec. 25, 2010. The gamma-ray emission lasted at least 28
minutes, which is unusually long. Follow-up observations of the
burst's afterglow by the Hubble Space Telescope and ground-based
observatories were unable to determine the object's distance.
Thoene's team proposes that the burst occurred in an exotic binary
system where a neutron star orbited a normal star that had just
entered its red giant phase, enormously expanding its outer
atmosphere. This expansion engulfed the neutron star, resulting in
both the ejection of the giant's atmosphere and rapid tightening of
the neutron star's orbit.
Once the two stars became wrapped in a common envelope of gas, the
neutron star may have merged with the giant's core after just five
orbits, or about 18 months. The end result of the merger was the
birth of a black hole and the production of oppositely directed jets
of particles moving at nearly the speed of light, followed by a weak supernova.
The particle jets produced gamma rays. Jet interactions with gas
ejected before the merger explain many of the burst's signature
oddities. Based on this interpretation, the event took place about
5.5 billion light-years away, and the team has detected what may be a
faint galaxy at the right location.
"Deep exposures using Hubble may settle the nature of this object,"
said Sergio Campana, who led the collision study at Brera Observatory
in Merate, Italy.
If it is indeed a galaxy, that would be evidence for the binary model.
On the other hand, if NASA's Chandra X-ray Observatory finds an X-ray
point source or if radio telescopes detect a pulsar, that goes against it.
Campana's team supports an alternative model that involves the tidal
disruption of a large comet-like object and the ensuing crash of
debris onto a neutron star located only about 10,000 light-years
away. The scenario requires the break-up of an object with about half
the mass of the dwarf planet Ceres. While rare in the asteroid belt,
such objects are thought to be common in the icy Kuiper belt beyond
Neptune. Similar objects located far away from the neutron star may
have survived the supernova that formed it.
Gamma-ray emission occurred when debris fell onto the neutron star.
Clumps of cometary material likely made a few orbits, with different
clumps following different paths before settling into a disk around
the neutron star. X-ray variations detected by Swift's X-Ray
Telescope that lasted several hours may have resulted from
late-arriving clumps that struck the neutron star as the disk formed.
In the early years of studying GRBs, astronomers had very few events
to study in detail and dozens of theories to explain them. In the
Swift era, astronomers have settled into two basic scenarios, either
the collapse of a massive star or the merger of a compact binary system.
"The beauty of the Christmas burst is that we must invoke two exotic
scenarios to explain it, but such rare oddballs will help us advance
the field," said Chryssa Kouveliotou, a co-author of the supernova
study at NASA's Marshall Space Flight Center in Huntsville, Ala.
NASA's Swift was launched in November 2004 and is managed by Goddard.
It is operated in collaboration with several U.S. institutions and
partners in the United Kingdom, Italy, Germany and Japan.
For more information and video associated with this release, visit:
http://www.nasa.gov/swift
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NASA, Library of Congress Establish Honorary Astrobiology Chair
WASHINGTON -- NASA and the Library of Congress have established theBaruch S. Blumberg NASA-Library of Congress chair in Astrobiology at
the Library's scholarly research organization, the John W. Kluge
Center in Washington. The chair is named for the late Nobel Laureate
and founding director of the NASA Astrobiology Institute, Baruch
"Barry" Blumberg.
Astrobiology is the study of the origins, evolution, distribution and
future of life in the universe. Astrobiology addresses three
fundamental questions: How did life begin and evolve? Is there life
elsewhere? What is the future of life on Earth and beyond?
Blumberg was awarded the 1976 Nobel Prize in physiology or medicine
for discovery of the Hepatitis B virus and development of a vaccine
to prevent Hepatitis B infection. He served as the NASA Astrobiology
Institute director from 1999 to 2002. The institute's mission is to
promote interdisciplinary research in astrobiology, train the next
generation of astrobiologists, provide scientific and technical
leadership for NASA space missions, and share astrobiology's
discoveries with learners of all ages.
"Relationships with external research organizations are critical to
NASA's success as a leader in science and technology," NASA Chief
Scientist Waleed Abdalati said. "Opportunities like the Blumberg
chair really help strengthen those relationships."
At the Library of Congress, Blumberg was a founding member of the
Scholar's Council, a 12-member group of distinguished scholars which
advises the Librarian of Congress on matters of scholarship.
"This collaboration between NASA and the Library of Congress is an
unparalleled opportunity to broaden public discourse on the
intersection of astrobiology and its societal implications," said
NASA Astrobiology Institute Director Carl Pilcher of NASA's Ames
Research Center at Moffett Field, Calif. "Astrobiology uses the tools
of modern science to address questions with philosophical, ethical
and theological implications. The chair will be able to use the vast
resources of the Library of Congress to explore these issues."
An annual international competition will be held to select a
chairperson, who will serve in residence at the Kluge Center for up
to one year, beginning in fall 2012.
Likely research topics include the societal implications of
discovering life beyond Earth, exploring whether life is rare in the
universe, or the ways astrobiology influences and is influenced by culture.
"For many years, Barry worked in his inimitable and energetic way to
connect scholars from astrobiology with those studying the
humanities," said Librarian of Congress James H. Billington. "We are
delighted to be moving forward with this important opportunity to
examine the societal implications of this frontier field."
Applications for the chair will be solicited by the Library of
Congress and reviewed by a panel jointly established by the library
and NASA. The first selection will be announced in spring 2012.
For more information about the NASA Astrobiology Program and the NASA
Astrobiology Institute, visit:
http://astrobiology.nasa.gov
For more information about the Kluge Center of the Library of
Congress, visit:
http://www.loc.gov/loc/kluge
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NASA Selects 300 Small Business Research and Technology Projects
WASHINGTON -- NASA has selected 300 small business proposals to enterinto negotiations for possible contract awards through the agency's
Small Business Innovation Research (SBIR) and the Small Business
Technology Transfer (STTR) programs.
These competitive awards-based programs encourage U.S. small
businesses and research institutions to engage in federal research,
development and commercialization. The programs enable teams to
explore technological potential while providing the incentive to
profit from new commercial products and services.
The SBIR program selected 260 proposals, which have a combined value
of approximately $33 million, for negotiation of Phase I feasibility
study contracts. The STTR program selected 40 proposals, with a
combined value of approximately $5 million, for negotiation of Phase I contracts.
"NASA's partnerships with small businesses and universities through
these programs brings space technologies to the marketplace, helping
start-ups and small businesses create new jobs and grow our economy
while meeting NASA's current and future mission needs," said Michael
Gazarik, director of NASA's Space Technology. "Breakthroughs in
technology for space exploration create the foundation for new
industries. We're excited to work with these new partners and look
forward to seeing their technologies mature into commercially viable products."
The SBIR and STTR programs address specific technology gaps in NASA
missions, while striving to complement other agency research
investments. Program results have benefited many NASA efforts,
including modern air traffic control systems, Earth-observing
spacecraft, the International Space Station and the Mars rovers.
Innovative research areas among proposals include:
- Improved technologies related to in-flight airframe and engine icing
hazards for piloted and drone vehicles to prevent encounters with
hazardous conditions and mitigation of their effects when they occur
- Design of electronics, hardened for radiation and thermal cycling,
which are capable of enduring the extreme temperature and radiation
environments of deep space, and the lunar and Martian surfaces
- Development of small, low-cost remote sensing and in situ
instruments to enable science measurement capabilities with smaller
or more affordable spacecraft that meet multiple mission needs while
making the best use of limited resources
- Innovative research in the areas of positioning, navigation and
timing that will enable accurate and precise determination of
location and orientation of spacecraft to allow corrections to
course, orientation and velocity to attain a desired destination
The highly competitive programs are based on a three-phase award
system. Phase I is a feasibility study to evaluate the scientific and
technical merit of an idea. Awards are typically for six months for
the SBIR contracts and 12 months for the STTR contracts, in amounts
up to $125,000. Firms successfully completing Phase I are eligible to
submit Phase II proposals, expanding on the results of Phase I. Phase
III includes commercialization of the results of Phase II, and
requires the use of private sector or non-SBIR federal funding as
innovations move from the laboratory to the marketplace.
The selected SBIR proposals were submitted by 196 small, high
technology firms in 37 states. The selected STTR proposals were
submitted by 36 small high technology firms in 13 states. As part of
the STTR program, the firms proposed to partner with 34 universities
or research institutions in 16 states.
NASA received 1,878 qualified Phase I proposals. The criteria used to
choose these selected proposals included technical merit and
feasibility; experience, qualifications and facilities; effectiveness
of the work plan; and, commercial potential and feasibility.
NASA's Ames Research Center at Moffett Field, Calif., manages the SBIR
program for the agency's Space Technology Program. NASA's 10 field
centers manage individual projects.
For a complete list of selected companies, visit:
http://sbir.nasa.gov
For more information about NASA's Office of the Chief Technologist and
the agency's Space Technology Program, visit:
http://www.nasa.gov/oct
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