David Kirkpatrick

March 11, 2009

NASA’s Fermi Telescope and the gamma-ray sky

Cool and interesting release from NASA on its Fermi Telescope and mapping gamma rays.

The release from today:

NASA’s Fermi Telescope Reveals Best-Ever View of the Gamma-Ray Sky

GREENBELT, Md., March 11 /PRNewswire-USNewswire/ — A new map combining nearly three months of data from NASA’s Fermi Gamma-ray Space Telescope is giving astronomers an unprecedented look at the high-energy cosmos. To Fermi’s eyes, the universe is ablaze with gamma rays from sources ranging from within the solar system to galaxies billions of light-years away.

(Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO)

“Fermi has given us a deeper and better-resolved view of the gamma-ray sky than any previous space mission,” said Peter Michelson, the lead scientist for the spacecraft’s Large Area Telescope (LAT) at Stanford University, Calif. “We’re watching flares from supermassive black holes in distant galaxies and seeing pulsars, high-mass binary systems, and even a globular cluster in our own.”

A paper describing the 205 brightest sources the LAT sees has been submitted to The Astrophysical Journal Supplement. “This is the mission’s first major science product, and it’s a big step toward producing our first source catalog later this year,” said David Thompson, a Fermi deputy project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md.

The LAT scans the entire sky every three hours when operating in survey mode, which is occupying most of the telescope’s observing time during Fermi’s first year of operations. These snapshots let scientists monitor rapidly changing sources.

The all-sky image released today shows us how the cosmos would look if our eyes could detect radiation 150 million times more energetic than visible light. The view merges LAT observations spanning 87 days, from August 4 to October 30, 2008.

The map includes one object familiar to everyone: the sun. “Because the sun appears to move against the background sky, it produces a faint arc across the upper right of the map,” Michelson explained. During the next few years, as solar activity increases, scientists expect the sun to produce growing numbers of high-energy flares. “No other instrument will be able to observe solar flares in the LAT’s energy range,” he said.

To better show individual sources, the new map was processed to suppress emissions from gas in the plane of our galaxy, the Milky Way. As a way of underscoring the variety of the objects the LAT is seeing, the Fermi team created a “top ten” list comprising five sources within the Milky Way and five beyond our galaxy.

The top sources within our galaxy include the sun; a star system known as LSI +61 303, which pairs a massive normal star with a superdense neutron star; PSR J1836+5925, which is one of many new pulsars, a type of spinning neutron star that emits gamma-ray beams; and the globular cluster 47 Tucanae, a sphere of ancient stars 15,000 light-years away.

Top extragalactic sources include NGC 1275, a galaxy that lies 225 million light-years away and is known for intense radio emissions; the dramatically flaring active galaxies 3C 454.3 and PKS 1502+106, both more than 6 billion light-years away; and PKS 0727-115, which is thought to be a type of active galaxy called a quasar.

The Fermi top ten also includes two sources — one within the Milky Way plane and one beyond it — that researchers have yet to identify. More than 30 of the brightest gamma-ray sources have no obvious counterparts at other wavelengths. “That’s good news. It means we’re seeing new objects,” Michelson said. “It also means that we have lots of work to do.”

NASA’s Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership mission, developed in collaboration with the U.S. Department of Energy and important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.

For images related to this release and the top ten LAT sources, please visit:

http://www.nasa.gov/mission_pages/GLAST/news/gammaray_best.html

For more information about the Fermi Gamma-ray Space Telescope, please visit:

http://www.nasa.gov/fermi

Photo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO
AP Archive:  http://photoarchive.ap.org/
PRN Photo Desk photodesk@prnewswire.com
Source: NASA
   

Web Site:  http://www.nasa.gov/

December 15, 2008

Unusual solar flare

The release:

AGU FEATURE: Solar Flare Surprise

GREENBELT, Md., Dec. 15 /PRNewswire-USNewswire/ — Solar flares are the most powerful explosions in the solar system. Packing a punch equal to a hundred million hydrogen bombs, they obliterate everything in their immediate vicinity. Not a single atom should remain intact.

At least that’s how it’s supposed to work.

“We’ve detected a stream of perfectly intact hydrogen atoms shooting out of an X-class solar flare,” says Richard Mewaldt of the California Institute of Technology. “What a surprise! If we can understand how these atoms were produced, we’ll be that much closer to understanding solar flares.”

The event occurred on Dec. 5, 2006. A large sunspot rounded the sun’s eastern limb and with little warning it exploded. On the “Richter scale” of flares, which ranks X1 as a big event, the blast registered X9, making it one of the strongest flares of the past 30 years.

NASA managers braced themselves.  Such a ferocious blast usually produces a blizzard of high-energy particles dangerous to both satellites and astronauts.   An hour later they arrived, but they were not the particles researchers expected.

NASA’s twin Solar TErrestrial RElations Observatory (STEREO) spacecraft made the discovery:  “It was a burst of hydrogen atoms,” says Mewaldt.  “No other elements were present, not even helium (the sun’s second most abundant atomic species). Pure hydrogen streamed past the spacecraft for a full 90 minutes.”

Next came 30 minutes of quiet. The burst subsided and STEREO’s particle counters returned to low levels. The event seemed to be over when a second wave of particles enveloped the spacecraft. These were the “broken atoms” flares are supposed to produce — protons and heavier ions such as helium, oxygen and iron. “Better late than never,” he says.

At first, this unprecedented sequence of events baffled scientists, but now Mewaldt and colleagues believe they’re getting to the bottom of the mystery.

First, how did the hydrogen atoms resist destruction?

“They didn’t,” says Mewaldt. “We believe they began their journey to Earth in pieces, as protons and electrons. Before they escaped the sun’s atmosphere, however, some of the protons captured an electron, forming intact hydrogen atoms. The atoms left the sun in a fast, straight shot before they could be broken apart again.” (For experts: The team believes the electrons were recaptured by some combination of radiative recombination and charge exchange.)

Second, what delayed the ions?

“Simple,” says Mewaldt. “Ions are electrically charged and they feel the sun’s magnetic field. Solar magnetism deflects ions and slows their progress to Earth. Hydrogen atoms, on the other hand, are electrically neutral. They can shoot straight out of the sun without magnetic interference.”

Imagine two runners dashing for the finish line. One (the ion) is forced to run in a zig-zag pattern with zigs and zags as wide as the orbit of Mars. The other (the hydrogen atom) runs in a straight line. Who’s going to win?

“The hydrogen atoms reached Earth almost two hours before the ions,” says Mewaldt.

Mewaldt believes that all strong flares might emit hydrogen bursts, but they simply haven’t been noticed before. He’s looking forward to more X-flares now that the two STEREO spacecraft are widely separated on nearly opposite sides of the Sun. (In 2006 they were still together near Earth.) STEREO-A and -B may be able to triangulate future bursts and pinpoint the source of the hydrogen.  This would allow the team to test their ideas about the surprising phenomenon.

“All we need now,” he says, “is some solar activity.”

For more information about this research, look for the article “STEREO Observations of Energetic Neutral Atoms during the 5 December 2006 Solar Flare” by R. A. Mewaldt et al., in a future issue of the Astrophysical Journal Letters.

  For more information and related images, visit:
  http://www.nasa.gov/topics/solarsystem/features/flare_surprise.html

  For more information about STEREO, please visit:
  http://www.nasa.gov/stereo

Source: NASA – Goddard Space Flight Center
 Web Site:  http://www.nasa.gov/

Outer space is closing in

Really.

The release from about 30 minutes ago:

Space Has Never Been Closer: NASA Instruments Document Contraction of the Boundary Between the Earth’s Ionosphere and Space

GREENBELT, Md., Dec. 15 /PRNewswire-USNewswire/ — Observations made by NASA instruments onboard an Air Force satellite have shown that the boundary between the Earth’s upper atmosphere and space has moved to extraordinarily low altitudes. These observations were made by the Coupled Ion Neutral Dynamics Investigation (CINDI) instrument suite, which was launched aboard the U.S. Air Force’s Communication/Navigation Outage Forecast System (C/NOFS) satellite on April 16, 2008.

The CINDI suite, which was built under the direction Principal Investigator Rod Heelis of the University of Texas at Dallas, includes both ion and neutral sensors and makes measurements of the variations in neutral and ion densities and drifts.

CINDI and C/NOFS were designed to study disturbances in Earth’s ionosphere that can result in a disruption of navigation and communication signals. The ionosphere is a gaseous envelope of electrically charged particles that surrounds our planet and it is important because Radar, radio waves, and global positioning system signals can be disrupted by ionospheric disturbances.

CINDI’s first discovery was, however, that the ionosphere was not where it had been expected to be. During the first months of CINDI operations the transition between the ionosphere and space was found to be at about 260 miles (420 km) altitude during the nighttime, barely rising above 500 miles (800 km) during the day. These altitudes were extraordinarily low compared with the more typical values of 400 miles (640 km) during the nighttime and 600 miles (960 km) during the day.

The height of the ionosphere/space transition is controlled in part by the amount of extreme ultraviolet energy emitted by the Sun and a somewhat contracted ionosphere could have been expected because C/NOFS was launched during a minimum in the 11-year cycle of solar activity. However, the size of the actual contraction caught investigators by surprise. In fact, when they looked back over records of solar activity, they found that C/NOFS had been launched during the quietest solar minimum since the space age began.

This extraordinary circumstance is providing an unparalleled opportunity to study the connection between the interior dynamics of the Sun and the response of the Earth’s space environment.

CINDI is a NASA sponsored Mission of Opportunity conducted by the University of Texas at Dallas. NASA’s Explorer Program at Goddard Space Flight Center, Greenbelt, Md., managed the CINDI mission. The Explorer Program provides frequent flight opportunities for world-class scientific investigations from space within heliophysics and astrophysics.

The CINDI investigation is carried out as an enhancement to the science objectives of the C/NOFS satellite undertaken by the Air Force Research Laboratory and the Space and Missile Command Test and Evaluation Directorate.

  For related images to this story, please visit:
  http://www.nasa.gov/topics/earth/features/outer_atmosphere.html

  For NASA’s CINDI Web site, visit:
  http://www.nasa.gov/mission_pages/cindi/index.html

  For the University of Texas at Dallas, CINDI web site, visit:
  http://cindispace.utdallas.edu/

  Air Force Research Laboratory Web site
  http://www.kirtland.af.mil/library/factsheets/factsheet.asp?id=12776

Source: NASA – Goddard Space Flight Center
   

Web Site:  http://www.nasa.gov/

November 18, 2008

NASA to launch nano satellite to study TGFs

Sounds like a wicked cool project.

The release:

NSF / NASA ‘Firefly’ CubeSat Mission to Study Link Between Lightning and Terrestrial Gamma Ray Flashes

Massive energy releases occur every day in the upper reaches of Earth’s atmosphere. Lightning may give rise to these bursts of radiation. However, unlike the well-known flashes of light and peals of thunder familiar to Earth-dwellers, these energy releases are channeled upward and can be detected only from space. Our atmosphere protects us from the effects of this radiation, but the mechanisms at work can impact Earth’s upper atmosphere and its space environment.

A new nano satellite mission, called ‘Firefly,’ sponsored by the National Science Foundation (NSF) and led by NASA’s Goddard Space Flight Center in Greenbelt, Md. will explore the relationship between lightning and these sudden bursts, called Terrestrial Gamma Ray Flashes (TGFs).

NASA’s Compton Gamma Ray Observatory (CGRO) first discovered TGFs in the 1990s. Designed to look outward at cosmic sources of gamma rays, CGRO also caught rare but tantalizing glimpses of gamma rays coming from Earth.

TGFs are likely produced by beams of very energetic electrons, which are accelerated in the intense electric fields generated by large thunderstorm systems. Before CGRO, many scientists thought these very energetic types of radiation could be generated only near the Sun, or in black holes, large galaxies, or neutron stars.

“These electron beams are more powerful than any produced in near-Earth space, and understanding their acceleration mechanisms will shed light on a physical process that may occur on other planets, or in astrophysical environments, as well as in the sun’s corona,” said Doug Rowland, principal investigator for the Firefly mission at NASA Goddard’s Space Weather Laboratory.

Firefly will explore which types of lightning produce these electron beams and associated TGFs. In addition, Firefly will explore the occurrence rate of TGFs that are weaker than any previously been studied. The result with be a better understanding of the effect that the millions of lightning flashes that occur worldwide each day have on the Earth’s upper atmosphere and near-Earth space environment.

“This mission could provide the first direct evidence for the relationship between lightning and TGFs, and addresses an important research question in atmospheric electricity,” said Anne-Marie Schmoltner, head of NSF’s Atmospheric Sciences Division’s Lower Atmosphere Research Section. “Identifying the source of terrestrial gamma ray flashes would be a great step toward fully understanding the physics behind lightning and its effect on the Earth’s atmosphere.”

The NSF CubeSat program represents a new “low cost access to space” approach to performing high-quality, targeted science on a smaller budget than is typical of larger satellite projects, which have price tags starting at $100 million. In contrast, the CubeSat Firefly will carry out its science mission in a much smaller package and at a considerably lower cost. The nano satellite is about the size of a football (4 by 4 by 12 inches). The cost to develop, launch, and operate Firefly for three years during its science mission is expected to be less than $1 million.

The Firefly mission also emphasizes student involvement as part of the ongoing effort to train the next generation of scientists and engineers. Students at Siena College, in Loudonville, N.Y., and the University of Maryland Eastern Shore, in Princess Anne, Md., will be involved in all phases of the Firefly mission.

“Integrating innovative and creative educational efforts with front-line research is what NSF is all about,” said NSF Deputy Director Kathie L. Olsen. “The new CubeSat program uses the transformational technology of CubeSats to do just that. The Firefly mission is a terrific example of a program that will pursue scientific discovery, while providing unique and inspiring educational opportunities.”

Firefly is funded and managed by the National Science Foundation, and will be developed as a collaborative effort by NASA Goddard Space Flight Center, Universities Space Research Association (USRA), Columbia, Md.; Siena College; University of Maryland Eastern Shore, Princess Anne, Md.; and the Hawk Institute for Space Sciences, in Pocomoke City, Md.

NASA Goddard, USRA, and Siena College will provide the instrument payload, while the Hawk Institute will build the CubeSat. NASA’s Wallops Flight Facility on Wallops Island, Va., will provide technical oversight for the integration of Firefly to the launch vehicle.

Firefly’s launch date is likely to be in 2010 or 2011. The micro satellite will fly as a secondary payload inside a Poly-Picosatellite Orbital Deployer (P-POD) provided by California Polytechnic State University, San Luis Obispo, Calif. Firefly will utilize the excess room and lift capacity not required by the primary mission payload.

For more information about NASA’s Compton Gamma Ray Observatory, visit:

http://heasarc.gsfc.nasa.gov/docs/cgro/index.html

 
 

Laura Layton
NASA’s Goddard Space Flight Center

The ‘Firefly’ CubeSat satellite will investigate Terrestrial Gamma Ray Flashes (TGFs) when it launches in 2010.
The ‘Firefly’ CubeSat satellite will investigate Terrestrial Gamma Ray Flashes (TGFs) when it launches in 2010.

November 13, 2008

Hubble directly sees extrasolar planet

Sorry about the release dump today, but I haven’t done one in a while and this just hit the inbox and was way, way too cool to pass up passing it along.

The release:

Hubble Directly Observes A Planet Orbiting Another Star

WASHINGTON, Nov. 13 /PRNewswire-USNewswire/ — NASA’s Hubble Space Telescope has taken the first visible-light snapshot of a planet circling another star.

(Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO)

Estimated to be no more than three times Jupiter’s mass, the planet, called Fomalhaut b, orbits the bright southern star Fomalhaut, located 25 light-years away in the constellation Piscis Australis, or the “Southern Fish.”

Fomalhaut has been a candidate for planet hunting ever since an excess of dust was discovered around the star in the early 1980s by NASA’s Infrared Astronomy Satellite, IRAS.

In 2004, the coronagraph in the High Resolution Camera on Hubble’s Advanced Camera for Surveys produced the first-ever resolved visible-light image of the region around Fomalhaut. It clearly showed a ring of protoplanetary debris approximately 21.5 billion miles across and having a sharp inner edge.

This large debris disk is similar to the Kuiper Belt, which encircles the solar system and contains a range of icy bodies from dust grains to objects the size of dwarf planets, such as Pluto.

Hubble astronomer Paul Kalas, of the University of California at Berkeley, and team members proposed in 2005 that the ring was being gravitationally modified by a planet lying between the star and the ring’s inner edge.

Circumstantial evidence came from Hubble’s confirmation that the ring is offset from the center of the star. The sharp inner edge of the ring is also consistent with the presence of a planet that gravitationally “shepherds” ring particles. Independent researchers have subsequently reached similar conclusions.

Now, Hubble has actually photographed a point source of light lying 1.8 billion miles inside the ring’s inner edge. The results are being reported in the November 14 issue of Science magazine.

“Our Hubble observations were incredibly demanding. Fomalhaut b is 1 billion times fainter than the star. We began this program in 2001, and our persistence finally paid off,” Kalas says.

“Fomalhaut is the gift that keeps on giving. Following the unexpected discovery of its dust ring, we have now found an exoplanet at a location suggested by analysis of the dust ring’s shape. The lesson for exoplanet hunters is ‘follow the dust,'” said team member Mark Clampin of NASA’s Goddard Space Flight Center in Greenbelt, Md.

Observations taken 21 months apart by Hubble’s Advanced Camera for Surveys’ coronagraph show that the object is moving along a path around the star, and is therefore gravitationally bound to it. The planet is 10.7 billion miles from the star, or about 10 times the distance of the planet Saturn from our sun.

The planet is brighter than expected for an object of three Jupiter masses. One possibility is that it has a Saturn-like ring of ice and dust reflecting starlight. The ring might eventually coalesce to form moons. The ring’s estimated size is comparable to the region around Jupiter and its four largest orbiting satellites.

Kalas and his team first used Hubble to photograph Fomalhaut in 2004, and made the unexpected discovery of its debris disk, which scatters Fomalhaut’s starlight. At the time they noted a few bright sources in the image as planet candidates. A follow-up image in 2006 showed that one of the objects is moving through space with Fomalhaut but changed position relative to the ring since the 2004 exposure. The amount of displacement between the two exposures corresponds to an 872-year-long orbit as calculated from Kepler’s laws of planetary motion.

Future observations will attempt to see the planet in infrared light and will look for evidence of water vapor clouds in the atmosphere. This would yield clues to the evolution of a comparatively newborn 100-million-year-old planet. Astrometric measurements of the planet’s orbit will provide enough precision to yield an accurate mass.

NASA’s James Webb Space Telescope, scheduled to launch in 2013 will be able to make coronagraphic observations of Fomalhaut in the near- and mid-infrared. Webb will be able to hunt for other planets in the system and probe the region interior to the dust ring for structures such as an inner asteroid belt. For more information about the Hubble Space Telescope, visit:

http://www.nasa.gov/hubble

Photo:  http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO
AP Archive:  http://photoarchive.ap.org/
PRN Photo Desk photodesk@prnewswire.com
Source: NASA
   

Web Site:  http://www.nasa.gov/

March 3, 2008

NASA image of Triangulum Galaxy

Filed under: et.al., Science — Tags: , , , , — David Kirkpatrick @ 7:35 pm

This is an awesome image of the M33 galaxy from NASA.

214437main_m33_uvot_400.jpg

The linked release:

NASA’s Swift satellite images a galaxy ablaze with starbirth
GREENBELT, Md. – Combining 39 individual frames taken over 11 hours of exposure time, NASA astronomers have created this ultraviolet mosaic of the nearby “Triangulum Galaxy.” “This is the most detailed ultraviolet image of an entire galaxy ever taken,” says Stefan Immler of NASA’s Goddard Space Flight Center in Greenbelt, Md. Immler used NASA’s Swift satellite to take the images, and he then assembled them into a mosaic that seamlessly covers the entire galaxy.

The Triangulum Galaxy is also called M33 for being the 33rd object in Charles Messier’s sky catalog. It is located about 2.9 million light-years from Earth in the constellation Triangulum. It is a member of our Local Group, the small cluster of galaxies that includes our Milky Way Galaxy and the Andromeda Galaxy (M31). Despite sharing our Milky Way’s spiral shape, M33 has only about one-tenth the mass. M33’s visible disk is about 50,000 light-years across, half the diameter of our galaxy.

Swift’s Ultraviolet/Optical Telescope (UVOT) took the images through three separate ultraviolet filters from December 23, 2007 to January 4, 2008. The mosaic showcases UVOT’s high spatial resolution. Individual star clusters and star-forming gas clouds are clearly resolved, even in the crowded nucleus of the galaxy. The image also includes Milky Way foreground stars and much more distant galaxies shining through M33.

Young, hot stars are prodigious producers of ultraviolet light, which heat up the surrounding gas clouds to such high temperatures that they radiate brightly in ultraviolet light. The image shows the giant star-forming region NGC 604 as a bright spot to the lower left of the galaxy’s nucleus. With a diameter of 1,500 light-years (40 times that of the Orion Nebula), NGC 604 is the largest stellar nursery in the Local Group.

“The ultraviolet colors of star clusters tell us their ages and compositions,” says Swift team member Stephen Holland of NASA Goddard. “With Swift’s high spatial resolution, we can zero in on the clusters themselves and separate out nearby stars and gas clouds. This will enable us to trace the star-forming history of the entire galaxy.”

“The entire galaxy is ablaze with starbirth,” adds Immler. “Despite M33’s small size, it has a much higher star-formation rate than either the Milky Way or Andromeda. All of this starbirth lights up the galaxy in the ultraviolet.”

###

Image credit: NASA/Swift Science Team/Stefan Immler.

For related images to this story, please visit on the Web:

http://www.nasa.gov/mission_pages/swift/bursts/m33.html

Written by: Robert Naeye
Goddard Space Flight Center