By focusing on the Orion Nebula almost continuously for 13 days, a team of
scientists used Chandra to obtain the deepest X-ray observations ever taken of
any star cluster.
"Although these flares may be creating havoc in the disks , they ultimately
could do more good than harm," said Feigelson. X-ray flares bombard these disks ,
likely giving them an electric charge. For imagery and
more information about the research on the Internet, visit:

http://hubblesite.
In addition to work on the Hubble, Bahcall was honored for extraordinary
service to NASA's space astronomy program and leadership of the National
Research Council's Decadal Survey. The Exceptional Scientific Achievement
Medal recognizes significant scientific contributions toward achieving NASA's
missions of exploration and discovery.nasa.

eclipsing observers

WASHINGTON, New results from NASA's Chandra X-ray
Observatory about the Orion Nebula imply super-flares torched our young solar
system., manages the Chandra
program for the agency's Science Mission Directorate. Several telescopes, including NASA's Spitzer Space
Telescope , have been searching for new star clusters in the Milky Way., and a
guest lecturer at Princeton University .

observational radiative

This charge, combined with motion of
the disk and the effects of magnetic fields, should create turbulence in the
disk.nasa.

binary depends

"
A key finding is the more violent stars produce flares one hundred times
as energetic as the more docile ones.
The numerous results from the Chandra Orion Ultradeep Project will appear
in an upcoming issue of The Astrophysical Journal Supplement. We were best friends; we were scientific
colleagues; and we were the love of each other's lives.

hydrodynamic iau

"Big X-ray flares could lead to planetary systems like ours, where Earth
is a safe distance from the sun," said Eric Feigelson of Penn State University
in University Park. Consequently, theories have predicted stars can be anywhere between 100
to 1,000 times more massive than the sun.

depends prosper

interacting disseminated

NASA'S Chandra Observatory Catches X-Ray Super-Flares

A star's weight ranges from less than one-tenth to more than 100 times the
mass of our sun. It resides 25,000 light-years away from Earth in our
galaxy's hub, a hotbed of massive star formation.

heavens gaskell

The Orion Nebula provides an unparalleled view of 1,400 young stars , 30 of
which are prototypes of the early sun. Using NASA's
Hubble Space Telescope, they made the first direct measurement within our
Milky Way Galaxy, and concluded stars cannot get any larger than about 150
times the mass of our sun. We looked at one
of the most massive clusters in our galaxy and found there is a sharp cutoff
to how large a star can form," he added.

NASA Honors Distinguished Astronomer With Medal

accretion separates

The Orion Nebula is the nearest rich stellar nursery,
located just 1,500 light years away from Earth. "Theories predict the more
massive the cluster, the more massive the stars within it.
Figer cautions the upper limit does not rule out the existence of stars
larger than 150 solar masses.J. "We had
an incredible 40 years together.

psr iau

Such X-ray flares likely affected the planet-forming disk around the
early sun, and may have enhanced the survival chances of Earth .

NASA's Hubble Weighs in on the Heaviest Stars in the Galaxy

Although Figer
did not find any stars larger than 130 solar masses, he conservatively set the
upper limit at 150 solar masses. "But
we found none. His next step is to pinpoint more clusters to
test his weight limit.
The finding is published in the March 10 issue of Nature. WASHINGTON, NASA Administrator Michael Griffin
awarded the agency's Exceptional Scientific Achievement Medal posthumously to
acclaimed American astronomer and astrophysicist John Bahcall.
Bahcall was a Richard Black Professor of Astrophysics in the School of
Natural Sciences at the Institute for Advanced Study in Princeton, N. In 1992 he received the NASA Distinguished Public Service Medal.

prosper psr

"
According to recent theoretical work, X-ray flares can create turbulence
when they strike planet-forming disks, and this affects the position of rocky
planets as they form. It produces sharp images, allowing
the telescope to see individual stars in a tightly packed cluster.

heavens pulsar

, Italy, France, Germany,
Taiwan, Japan and the Netherlands.

pulsar eclipsing

"
About half of the young suns in Orion show evidence of planet-forming
disks including four lying at the center of proplyds (proto-planetary disks)
imaged by NASA's Hubble Space Telescope.

NASA's Marshall Space Flight Center, Huntsville, Ala.
Additional information and images pertaining to this research is available at:

http://chandra . It also gives the strongest backing yet to
the notion stars have a weight limit.
Figer's finding is consistent with statistical studies of smaller-mass
star clusters in our galaxy and with observations of a massive star cluster
known as R136 in our galactic neighbor, the Large Magellanic Cloud.

separates prosper

Astronomers have been uncertain about how large a star can get before it
cannot hold itself together and blows apart.
Figer used Hubble's Near Infrared Camera and Multi-Object Spectrometer to
study hundreds of stars ranging from six to 130 solar masses. "I have followed the career of John Bahcall and long admired his
scientific accomplishments and passionate advocacy for space-based astronomy.

jetting discoverers

Scientists have discovered these young
stars erupt in enormous flares that dwarf, in energy , size and frequency,
anything seen from our sun today. "Stars with smaller flares, on the other
hand , might end up with Earth-like planets plummeting into the star. Specifically, this turbulence can help prevent planets
from rapidly migrating towards the young star.nasa.
"This is an incredible cluster that contains a rich collection of some of
the most massive stars in the galaxy, yet it appears to be missing stars more
massive than 150 times the mass of our sun," said astronomer Donald Figer of
the Space Telescope Science Institute, Baltimore. He also collaborated with Francisco
Najarro of the Instituto de Estructura de la Materia in Madrid, Spain."
For more information about NASA and agency programs on the Web, visit:

http://www.

algol prosper

Northrop Grumman ,
Redondo Beach, Calif. WASHINGTON, Astronomers have taken an important
step toward establishing an upper limit to the masses of stars.

interacting observational

Hubble's infrared camera is well suited to analyze the cluster, because it
penetrates the dusty core of our galaxy. In
1998 he received the National Medal of Science from President Clinton.

separates gaskell

This difference may specifically affect
the fate of planets that are relatively small and rocky, like the Earth.harvard.
Griffin presented the medal today to Bahcall's widow, Neta Bahcall, during
a ceremony at the 207th meeting of the American Astronomical Society in
Washington.
"In his 70 years, John Bahcall was a legend in this community," Griffin
said. He
later partnered with astronomers Lyman Spitzer and George Field to develop the
bold concept that became Hubble.

eclipsing psr

He is the principal investigator for the international
Chandra Orion Ultradeep Project. Knowing how large
a star can form may offer important clues to how the universe makes them. The Arches cluster is a youngster about 2 to
2. "Standard theories predict 20 to 30
stars with masses between 130 and 1,000 solar masses," Figer explained.
"John always did what he loved, and he did it until the end," said Neta
Bahcall.

psr gaskell

"We are
getting a unique look at stars between one and 10 million years old -- a time
when planets form. The team
contains 37 scientists from institutions in the U.S. If they had formed, we would have seen them," he added."
Among Bahcall's five decades of accomplishments was his groundbreaking
work in the 1960s toward explaining the scientific mysteries of the sun. She is a professor of astrophysical sciences at Princeton.

interacting jetstreams

Although astronomers know stars come in a variety of masses,
they don't know if the bodies have a weight limit at birth.5 million years old.gov

His lifetime
of achievement included work on development of the Hubble Space Telescope.

iau pulsar

The astronomers used the Hubble to probe the Arches cluster, the densest
in our galaxy. The finding takes astronomers closer to understanding the
complex star formation process.
Najarro produced detailed models to confirm the masses, chemical abundances
and ages of the Arches cluster stars.org/news/2005/05

For information about NASA and agency programs on the Internet, visit:

http://www.gov/home

disseminated accretion

"These flares may be acting
like a planetary protection program. In this region huge clouds
of gas collide to form behemoth stars.

iau disseminated

"We don't have a time machine to see how the young sun behaved, but the
next best thing is to observe sun-like stars in Orion," said Scott Wolk of
Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., was the prime development contractor for the
observatory . The Smithsonian Astrophysical Observatory controls science and
flight operations from the Chandra X-ray Center in Cambridge, Mass.edu
+
http://chandra. Astronomers don't know enough
about the details of the star-formation process to estimate a star's upper
mass.
Figer estimated the stars' masses by measuring the ages of the cluster and
the brightness of the individual stars.

hydrodynamic prosper

gov

He served as president of the
American Astronomical Society and president elect of the American Physical
Society.