Physics & Mathematics

Discovery of nearest known brown dwarf

A team of European astronomers has discovered a Brown Dwarf object (a ‘failed’ star) less than 12 light-years from the Sun. It is the nearest yet known. Now designated Epsilon Indi B, it is a companion to a well-known bright star in the southern sky, Epsilon Indi, previously thought to be single. The binary system is one of the twenty nearest stellar systems to the Sun. The brown dwarf was discovered from the comparatively rapid motion across the sky which it shares with its brighter companion : the pair move a full lunar diameter in less than 400 years. It was first identified using digitised archival photographic plates from the SuperCOSMOS Sky Surveys and confirmed using data from the Two Micron All Sky Survey. Follow-up observations with the near-infrared sensitive SOFI instrument on the ESO 3.5-m New Technology Telescope (NTT) at the La Silla Observatory confirmed its nature and has allowed measurements of its physical properties.

Is there a ‘Planet X’?

Forget about X-ray vision and gamma ray defence beams. Planet X isn’t a superhero home world but a hypothetical 10th planet in our solar system. “I think this question tends to be intriguing because of X – the unknown,” says astronomer John Percy. “But right now, we just don’t know if there is another planet lurking on the edges of the solar system.” Percy says there are thousands of small objects orbiting the Sun beyond Neptune and Pluto. Called Kuiper Belt Objects, astronomers do not consider these to be planets because of their relatively small size – the largest, Quaoar, is half the size of Pluto. They are icy and disintegrate if diverted by another cosmic body into an orbit closer to the Sun. If this occurs, he adds, they appear to us as comets.

Surprising Image Revises Understanding of Dwarf Galaxies

An intensive study of a neighboring dwarf galaxy has surprised astronomers by showing that most of its molecular gas — the raw material for new stars — is scattered among clumps in the galaxy’s outskirts, not near its center as they expected. “This tells us that the galaxies we call dwarf irregulars are even more irregular than we thought,” said Fabian Walter, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. “Our new work also shows that these galaxies probably are useful ‘laboratories’ for studying how stars were formed when the Universe was young,” Walter added.

Robotic telescope catches early afterglow of gamma-ray burst

A team of California astronomers announced today that its robotic telescope has captured one of the earliest images ever of the visible afterglow of a gamma-ray burst. The telescope started its exposures 108 seconds after the burst was detected by the HETE-2 satellite and continued for more than 2.5 hours, until brightening of the dawn sky halted the observations. The unprecedented record of the fading glow, captured Dec. 11, will help theorists as they puzzle out the physics of these bizarre cataclysmic events, which are heralded by a brief burst of energetic gamma rays and X-rays emitted billions of years ago and followed by a fading optical light.

Three Distant Quasars Found at Edge of the Universe

Astronomers have discovered three of the oldest, most distant quasars yet found — quasars close to the Big Bang that began the universe. Xiaohui Fan of the University of Arizona’s Steward Observatory in Tucson, Ariz., will present the results at the American Astronomical Society’s meeting in Seattle. Fan, leader of the team that discovered the objects, explained that these distant quasars — compact but luminous objects thought to be powered by super-massive black holes — reach back to a time when the universe was just 800 million years old. The highest redshift quasar is roughly 13 billion light years away and was discovered recently in the constellation Ursa Major.

Zooming-in on star formation in the Orion Nebula

A team of astronomers is using one of the most advanced ground-based telescopes in the world to “zoom-in” on protostars in the Orion Nebula, revealing in unprecedented detail a variety of phenomena associated with star and planet formation in the presence of extremely massive, luminous stars. These phenomena include high-velocity jets of gas launched from the protostars themselves; evaporation flows driven by the intense radiation of nearby massive stars; and colliding winds that form thin, filamentary sheets of gas.

Giant Radio Jet Coming From Wrong Kind of Galaxy

Giant jets of subatomic particles moving at nearly the speed of light have been found coming from thousands of galaxies across the Universe, but always from elliptical galaxies or galaxies in the process of merging — until now. Using the combined power of the Hubble Space Telescope, the Very Large Array (VLA) and the 8-meter Gemini-South Telescope, astronomers have discovered a huge jet coming from a spiral galaxy similar to our own Milky Way.

Black holes form first, galaxies follow

A new study has uncovered more evidence that black holes form before the galaxies that contain them. The finding could help resolve a long-standing debate, says the study’s lead scientist. Marianne Vestergaard, a postdoctoral fellow in astronomy at Ohio State, came to this conclusion when she studied a collection of very energetic, active galaxies known as quasars as they appeared some 12 billion years ago, when the universe was only one billion years old. While the quasars were obviously young — they contained large stellar nurseries in which new stars were forming — each also contained a very massive, fully formed black hole.

Astronomers identify new type of star

A new type of star has been discovered lurking as a low mass component in a very compact binary star system. Astronomers announced today at the American Astronomical Society Meeting in Seattle, Wash., that they have confirmed the existence of a new variety of stellar end-product. This previously unknown type of star has some properties similar to brown dwarf stars and may help astronomers understand some of the recently discovered extra-solar planets in close proximity to their suns.

NASA technology could help treat anxiety, migraine and hypertension

An technology developed by NASA to help its astronauts combat motion sickness during space flight will be available in March for a much wider range of human health and performance uses. The technology, which helps an individual control aspects of their autonomal nervous system — which regulates involuntary bodily functions, such as breathing, heartbeat, sweating, blood vessel dilation and glandular secretions — could have use in treating conditions as varied as migraine headache, high blood pressure and panic attacks.

Astronomers Detect a Faint Debris Trail in the Andromeda Galaxy

The discovery of a faint trail of stars in the nearby Andromeda galaxy offers new evidence that large spiral galaxies have grown by gobbling up smaller satellite galaxies. Andromeda (also known as M31) is the nearest large galaxy to our own Milky Way and is very similar to it in appearance. Studying Andromeda gives astronomers an external perspective on a galaxy much like our own–it’s like looking at a bigger sibling of our galaxy.

Astronauts to fight fire with fog during Space Shuttle flight

During a January flight of Space Shuttle Columbia, astronauts will test a new commercial fire-fighting system that puts out blazes with a fine water mist — instead of using harmful chemicals or large quantities of water that damage property. “The fire-fighting industry is in search of a new tool that doesn’t use dangerous chemicals or douse fires with huge quantities of water that cause extensive property damage,” said Mark Nall, director of the Space Product Development Program at NASA’s Marshall Space Flight Center in Huntsville, Ala. “By flying this commercial experiment on the STS-107 Columbia mission, NASA is helping industry design a cost-effective, environmentally friendly system for putting out fires.”

Supernova Factory announces 34 supernovae in one year

The Nearby Supernova Factory (SNfactory), an international collaboration based at Lawrence Berkeley National Laboratory, today announced that it had discovered 34 supernovae during the first year of the prototype system’s operation — all but two of them in the last four months alone. The announcement was made at the 201st meeting of the American Astronomical Society in Seattle. “This is the best performance ever for a ‘rookie’ supernova search,” said Greg Aldering of Berkeley Lab’s Physics Division, principal investigator of the SNfactory. “We have shown we can discover supernovae at the rate of nine a month, a rate other searches have reached only after years of trying.”

Extrasolar meteors hint at distant planet formation

Candian astronomers say that detecting microscopic meteors from other solar systems could provide clues about the formation of planets like Earth. Dust streams from our sun’s stellar neighbours consist of tiny grains of pulverized rock ejected from a disk of dust and debris that commonly surrounds young stars, says Joseph Weingartner, a post-doctoral fellow at the University of Toronto’s Canadian Institute for Theoretical Astrophysics. According to Professor Norman Murray, associate director of CITA and co-author of the study, “if we can detect these grains and trace them back to the star system that they came from, we’d have very good evidence of planet formation going on in that system.” Weingartner presented the study Jan. 6 at the American Astronomical Society meeting in Seattle, Wash.