Nicknamed the “Peony nebula star,” the bright stellar bulb was revealed by NASA’s Spitzer Space Telescope and other ground-based telescopes. It blazes with the light of an estimated 3.2 million suns.

The reigning “brightest star” champion is Eta Carina, with a whopping solar wattage of 4.7 million suns. But according to astronomers, it’s hard to pin down an exact brightness, or luminosity, for these scorching stars, so they could potentially shine with a similar amount of light.

“The Peony nebula star is a fascinating creature. It appears to be the second-brightest star that we now know of in the galaxy, and it’s located deep into the galaxy’s center,” said Lidia Oskinova of Potsdam University in Germany. “There are probably other stars just as bright if not brighter in our galaxy that remain hidden from view.” Oskinova is principal investigator for the research and second author of a paper appearing in a future issue of the journal Astronomy and Astrophysics.

Scientists already knew about the Peony nebula star, but because of its sheltered location in the dusty central hub of our galaxy, its extreme luminosity was not revealed until now. Spitzer’s dust-piercing infrared eyes can see straight into the heart of our galaxy, into regions impenetrable by visible light. Likewise, infrared data from the European Southern Observatory’s New Technology Telescope in Chile were integral in calculating the Peony nebula star’s luminosity.

“Infrared astronomy opens extraordinary views into the environment of the central region of our galaxy,” said Oskinova.

The brightest stars in the universe are also the biggest. Astronomers estimate the Peony nebula star kicked off its life with a hefty mass of roughly 150 to 200 times that of our sun. Stars this massive are rare and puzzle astronomers because they push the limits required for stars to form. Theory predicts that if a star starts out too massive, it can’t hold itself together and must break into a double or multiple stars instead.

Not only is the Peony nebula star hefty, it also has a wide girth. It is a type of giant blue star called a Wolf-Rayet star, with a diameter roughly 100 times that of our sun. That means this star, if placed where our sun is, would extend out to about the orbit of Mercury.

With so much mass, the star barely keeps itself together. It sheds an enormous amount of stellar matter in the form of strong winds over its relatively short lifetime of a few million years. This matter is pushed so hard by strong radiation from the star that the winds speed up to about 1.6 million kilometers per hour (one million miles per hour) in only a few hours.

Ultimately, the Peony nebula star will blow up in a fantastic explosion of cosmic proportions called a supernova. In fact, Oskinova and her colleagues say that the star is ripe for exploding soon, which in astronomical terms mean anytime from now to millions of years from now.

“When this star blows up, it will evaporate any planets orbiting stars in the vicinity,” said Oskinova. “Farther out from the star, the explosion could actually trigger the birth of new stars.”

In addition to the star itself, the astronomers noted a cloud of dust and gas, called a nebula, surrounding the star. The team nicknamed this cloud the Peony nebula because it resembles the ornate flower.

“The nebula was probably created from the spray of dust leaking off the massive Peony nebula star,” said Andreas Barniske of Potsdam University, lead author of the study.

Wolf-Rainer Hamann, also of Potsdam University, is another co-author of the paper and the principal investigator of a Spitzer program enabling this research.

NASA’s Jet Propulsion Laboratory, Pasadena, Calif., 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, also in Pasadena. Caltech manages JPL for NASA. Spitzer’s infrared spectrograph, which was used to determine the luminosity of the Peony nebula star, was built by Cornell University, Ithaca, N.Y. Its development was led by Jim Houck of Cornell.

he fluffy-looking galaxy, officially named Messier 101, is dominated by a mishmash of spiral arms. In Spitzer’s new view, in which infrared light is color coded, the galaxy sports a swirling blue center and a unique, coral-red outer ring.

A new paper appearing July 20 in the Astrophysical Journal explains why this outer ring stands out. According to the authors, the red color highlights a zone where organic molecules called polycyclic aromatic hydrocarbons, which are present throughout most of the galaxy, suddenly disappear.

Polycyclic aromatic hydrocarbons are dusty, carbon-containing molecules found in star nurseries, and on Earth in barbeque pits, exhaust pipes and anywhere combustion reactions take place. Scientists believe this space dust has the potential to be converted into the stuff of life.

“If you were going look for life in Messier 101, you would not want to look at its edges,” said Karl Gordon of the Space Telescope Science Institute in Baltimore, Md. “The organics can’t survive in these regions, most likely because of high amounts of harsh radiation.” To view Spitzer’s Pinwheel, visit http://www.nasa.gov/mission_pages/spitzer/multimedia/20080721a.html

The Pinwheel galaxy is located about 27 million light-years away in the constellation Ursa Major. It has one of the highest known gradients of metals (elements heavier than helium) of all nearby galaxies in our universe. In other words, its concentrations of metals are highest at its center, and decline rapidly with distance from the center. This is because stars, which produce metals, are squeezed more tightly into the galaxy’s central quarters.

Gordon and his team used Spitzer to learn about the galaxy’s gradient of polycyclic aromatic hydrocarbons. The astronomers found that, like the metals, the polycyclic aromatic hydrocarbons decrease in concentration toward the outer portion of the galaxy. But, unlike the metals, these organic molecules quickly drop off and are no longer detected at the very outer rim.

“There’s a threshold at the rim of this galaxy, where the organic material is getting destroyed,” said Gordon.

The findings also provide a better understanding of the conditions under which the very first stars and galaxies arose. In the early universe, there were not a lot of metals or polycyclic aromatic hydrocarbons around. The outskirt of the Pinwheel galaxy therefore serves as a close-up example of what the environment might look like in a distant galaxy.

In this image, infrared light with a wavelength of 3.6 microns is colored blue; 8-micron light is green; and 24-micron light is red. All three of Spitzer instruments were used in the study: the infrared array camera, the multiband imaging photometer and the infrared spectrograph.

Other authors of the paper include Charles Engelbracht, George Rieke, Karl A. Misselt, J.D. Smith and Robert Kennicutt, Jr. of the University of Arizona, Tucson. Smith is also associated with the University of Toledo, Ohio, and Kennicutt is also associated with the University of Cambridge, England.

NASA’s Jet Propulsion Laboratory, Pasadena, Calif., 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, also in Pasadena. Caltech manages JPL for NASA. Spitzer’s infrared array camera was built by NASA’s Goddard Space Flight Center, Greenbelt, Md. The instrument’s principal investigator is Giovanni Fazio of the Harvard-Smithsonian Center for Astrophysics. Spitzer’s infrared spectrograph was built by Cornell University, Ithaca, N.Y. Its development was led by Jim Houck of Cornell. The multiband imaging photometer for Spitzer was built by Ball Aerospace Corporation, Boulder, Colo., and the University of Arizona, Tucson. Its principal investigator is George Rieke of the University of Arizona.

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The latest discovery, COROT-exo-4b is an exoplanet of about the same size as Jupiter. It takes 9.2 days to orbit its star, the longest period for any transiting exoplanet ever found.

The team has found that the star, which is slightly larger than our Sun, is rotating at the same pace as the planet’s period of revolution. This is quite a surprise for the team, as the planet is thought to be too low in mass and too distant from its star, for the star to have any major influence on its rotation.

Launched in December 2006, COROT is the first space-based mission designed to search for exoplanets. Located outside Earth’s atmosphere, the satellite is designed to detect rocky exoplanets almost as small as Earth. The satellite uses transits, the tiny dips in the light output from a star when a planet passes in front of it, to detect and study planets. This is followed up by extensive ground-based observations.

Monitoring COROT-exo-4b continuously over several months, the team tracked variations in its brightness between transits. They derived its period of rotation by monitoring dark spots on its surface that rotated in and out of view.

It is not known whether COROT-exo-4b and its star have always been rotating in sync since their formation about 1000 million years ago, or if the star’s rotation synchronized later. Studying such systems with COROT will help scientists gain valuable insight into star-planet interactions.

This is the first transiting exoplanet found with such a peculiar combination of mass and period of rotation. There is surely something special about how it formed and evolved.

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At 12:05 p.m. EDT, the Delta II rocket easily lifted the GLAST spacecraft off the launch pad, out of smoke and clouds and into a beautiful Florida sky headed for space.

The second firing of the second-stage engine was confirmed as was successful spacecraft separation. Applause rippled through the launch control center as separation confirmation was received.

GLAST is now on its own with its solar arrays deployed and placed into a circular orbit 350 miles above the Earth, prepared to monitor the universe and the mysterious gamma-ray bursts.

GLAST is a powerful space observatory that will explore the most extreme environments in the universe, and search for signs of new laws of physics and what composes the mysterious dark matter, explain how black holes accelerate immense jets of material to nearly light speed, and help crack the mysteries of the staggeringly powerful explosions known as gamma-ray bursts.

With high sensitivity GLAST is the first imaging gamma-ray observatory to survey the entire sky every day. It will give scientists a unique opportunity to learn about the ever-changing universe at extreme energies. GLAST will detect thousands of gamma-ray sources, most of which will be supermassive black holes in the cores of distant galaxies.

GLAST: Exploring the Extreme Universe

GLAST is a powerful space observatory that will open a wide window on the universe. Gamma rays are the highest-energy form of light, and the gamma-ray sky is spectacularly different from the one we perceive with our own eyes. With a huge leap in all key capabilities, GLAST data will enable scientists to answer persistent questions across a broad range of topics, including supermassive black-hole systems, pulsars, the origin of cosmic rays, and searches for signals of new physics.

The mission is an astrophysics and particle physics partnership, developed by NASA in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.

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And everything’s working.

On the Large Area Telescope, the principal instrument on GLAST, the computers booted up properly, the 16 gamma-ray detectors came to life, and communications checked out well. The observatory’s navigation system is following directions from the ground to turn toward interesting objects.

“I’ve been watching space projects for 30 years or so and I’ve never seen one go as smoothly as this one,” said Roger Blandford, the director of the Kavli Institute for Particle Astrophysics and Cosmology, which is housed both on the main Stanford campus and at the Stanford Linear Accelerator Center (SLAC).

The telescope will see the normally invisible gamma rays from stars and other cosmic objects and offer a more complete view of some of the most violent events in the universe. GLAST will study, among other things, enormously powerful gamma-ray bursts, strange beams of charged particles from spinning black holes and pulses of energy from spinning neutron stars.

It may even find the gamma-ray signature of dark matter, the unseen material that may hold the universe together.

Data from the satellite already has begun flowing to the Instrument Science Operations Center at SLAC, where it is used to calibrate the telescope for the work ahead. The telescope is weeding out unwanted cosmic rays and measuring the first of the billion or so gamma rays it should eventually see from cosmic sources.

Some 30 collaboration members from around the world have come to SLAC to assist in the commissioning phase to bring the Large Area Telescope to its mission-ready performance.

“Everybody’s really happy,” said Rob Cameron, the manager of the SLAC operations center. “We’ve got plenty of work to do. We’ve got to calibrate the instrument, tune it up to prepare it for science.”

GLAST is a NASA project, a consortium of six countries and 14 U.S. research institutions. At Stanford, project members come from SLAC, a U.S. Department of Energy laboratory; the Physics Department; the Hansen Experimental Physics Laboratory; and the Kavli Institute for Particle Astrophysics and Cosmology.

The first 14 images in the gallery were handpicked by Mark Lemmon, SSI lead scientist from Texas A&M University, College Station. The camera took them images between the eighth Martian day, or sol, of the mission (June 2, 2008) and the 36th sol (July 1, 2008).

Red and blue 3D glasses (red for left eye, blue for right eye) are needed to properly view these stereo images.

The Phoenix mission is led by Peter Smith of the University of Arizona with project management at JPL and development partnership at Lockheed Martin, Denver. International contributions come from the Canadian Space Agency; the University of Neuchatel; the universities of Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany; and the Finnish Meteorological Institute

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The object, SN 2008D, is thus probably among the weakest explosions that produce very fast moving jets. This discovery represents a crucial milestone in the understanding of the most violent phenomena observed in the Universe.

These striking results, partly based on observations with ESO’s Very Large Telescope, will appear tomorrow in Science Express, the online version of Science.

Stars that were at birth more massive than about 8 times the mass of our Sun end their relatively short life in a cosmic, cataclysmic firework lighting up the Universe. The outcome is the formation of the densest objects that exist, neutron stars and black holes. When exploding, some of the most massive stars emit a short cry of agony, in the form of a burst of very energetic light, X- or gamma-rays.

In the early afternoon (in Europe) of 9 January 2008, the NASA/STFC/ASI Swift telescope discovered serendipitously a 5-minute long burst of X-rays coming from within the spiral galaxy NGC 2770, located 90 million light-years away towards the Lynx constellation. The Swift satellite was studying a supernova that had exploded the previous year in the same galaxy, but the burst of X-rays came from another location, and was soon shown to arise from a different supernova, named SN 2008D.

Researchers at the Italian National Institute for Astrophysics (INAF), the Max-Planck Institute for Astrophysics (MPA), and at various other institutions have observed the supernova at great length. The team is led by Paolo Mazzali of INAF’s Padova Observatory and MPA.

“What made this event very interesting,” says Mazzali, “is that the X-ray signal was very weak and ‘soft’ [1], very different from a gamma-ray burst and more in line with what is expected from a normal supernova.”

So, after the supernova was discovered, the team rapidly observed it from the Asiago Observatory in Northern Italy and established that it was a Type Ic supernova.

“These are supernovae produced by stars that have lost their hydrogen and helium-rich outermost layers before exploding, and are the only type of supernovae which are associated with (long) gamma-ray bursts,” explains Mazzali. “The object thus became even more interesting!”

Earlier this year, an independent team of astronomers reported in the journal Nature that SN 2008D is a rather normal supernova. The fact that X-rays were detected was, they said, because for the first time, astronomers were lucky enough to catch the star in the act of exploding.

Mazzali and his team think otherwise. “Our observations and modeling show this to be a rather unusual event, to be better understood in terms of an object lying at the boundary between normal supernovae and gamma-ray bursts.”

The team set up an observational campaign to monitor the evolution of the supernova using both ESO and national telescopes, collecting a large quantity of data. The early behaviour of the supernova indicated that it was a highly energetic event, although not quite as powerful as a gamma-ray burst. After a few days, however, the spectra of the supernova began to change. In particular Helium lines appeared, showing that the progenitor star was not stripped as deeply as supernovae associated with gamma-ray bursts.

Over the years, Mazzali and his group have developed theoretical models to analyse the properties of supernovae. When applied to SN2008D, their models indicated that the progenitor star was at birth as massive as 30 times the Sun, but had lost so much mass that at the time of the explosion the star had a mass of only 8-10 solar masses. The likely result of the collapse of such a massive star is a black hole.

“Since the masses and energies involved are smaller than in every known gamma-ray burst related supernova, we think that the collapse of the star gave rise to a weak jet, and that the presence of the Helium layer made it even more difficult for the jet to remain collimated, so that when it emerged from the stellar surface the signal was weak,” says Massimo Della Valle, co-author.

“The scenario we propose implies that gamma-ray burst-like inner engine activity exists in all supernovae that form a black hole,” adds co-author Stefano Valenti.

“As our X-ray and gamma-ray instruments become more advanced, we are slowly uncovering the very diverse properties of stellar explosions,” explains Guido Chincarini, co-author and the Principal Investigator of the Italian research on gamma-ray bursts. “The bright gamma-ray bursts were the easiest to discover, and now we are seeing variations on a theme that link these special events to more normal ones.”

These are however very important discoveries, as they continue to paint a picture of how massive star end their lives, producing dense objects, and injecting new chemical elements back into the gas from which new stars will be formed.

[1] Astronomers classify X-rays as soft when the relative amount of high-energy X-rays is smaller than that of lower-energy ones.

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It is a spin-half lepton that participates in electromagnetic interactions, and its mass is less than one thousandth of that of the smallest atom.

Its electric charge is defined by convention to be negative, with a value of -1 in atomic units.

Together with atomic nuclei, electrons make up atoms; their interaction with adjacent nuclei is the main cause of chemical bonding.

The electron is one of a class of subatomic particles called leptons, which are believed to be fundamental particles (that is, they cannot be broken down into smaller constituent parts)..

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It is also called “high energy physics”, because many elementary particles do not occur under normal circumstances in nature, but can be created and detected during energetic collisions of other particles, as is done in particle accelerators.

Modern particle physics research is focused on subatomic particles, which have less structure than atoms.

These include atomic constituents such as electrons, protons, and neutrons (protons and neutrons are actually composite particles, made up of quarks), particles produced by radiative and scattering processes, such as photons, neutrinos, and muons, as well as a wide range of exotic particles.

Strictly speaking, the term particle is a misnomer because the dynamics of particle physics are governed by quantum mechanics.

As such, they exhibit wave-particle duality, displaying particle-like behavior under certain experimental conditions and wave-like behavior in others (more technically they are described by state vectors in a Hilbert space).

All the particles and their interactions observed to date can be described by a quantum field theory called the Standard Model.

The Standard Model has 40 species of elementary particles (24 fermions, 12 vector bosons, and 4 scalars), which can combine to form composite particles, accounting for the hundreds of other species of particles discovered since the 1960s..

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Since any quantum system can have one or more quantum numbers, it is a futile job to list all possible quantum numbers.

The question of how many quantum numbers are needed to describe any given system has no universal answer, although for each system one must find the answer for a full analysis of the system.

The most widely studied set of quantum numbers is that for a single electron in an atom: not only because it is useful in chemistry, being the basic notion behind the periodic table, valence (chemistry) and a host of other properties, but also because it is a solvable and realistic problem, and, as such, finds widespread use in textbooks..

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