Free Republic

A sharp-eyed instrument on the Very Large Telescope has given astronomers a peek at the heart of a nearby galaxy, revealing a host of young, massive and dusty stellar nurseries and a possible twin of our own Milky Way's supermassive black hole. The galaxy, dubbed NGC 253, is one of the brightest and dustiest spiral galaxies in the sky. It is also known as the Sculptor Galaxy, because it is located in the Sculptor constellation. The Sculptor Galaxy is a starbust galaxy, so-called because of very intense star formation there. Astronomers from the Instituto de Astrofísica de Canarias in Spain...

A research team that has developed the first complete map of the Milky Way galaxy's spiral arms. The map shows the inner part of the Milky Way has two prominent, symmetric spiral arms, which extend into the outer galaxy where they branch into four spiral arms. "For the first time these arms are mapped over the entire Milky Way," said Iowa State University's Martin Pohl, an associate professor of physics and astronomy. "The branching of two of the arms may explain why previous studies -- using mainly the inner or mainly the outer galaxy -- have found conflicting numbers of...

Our galaxy is much bigger than once thought, according to research presented at a major astronomy meeting this week. The results suggest the Milky Way is roughly the same size as Andromeda, the largest galaxy in our local group. What is more, it is moving 15% faster than earlier predictions. The greater mass means that future collisions with nearby galaxies could happen sooner than thought, according to the researchers. Mark Reid of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, US, and his colleagues made use of the Very Long Baseline Array (VLBA) to deduce the Milky Way's size and...

Long Beach, CA - Fasten your seat belts -- we're faster, heavier, and more likely to collide than we thought. Astronomers making high-precision measurements of the Milky Way say our Galaxy is rotating about 100,000 miles per hour faster than previously understood. That increase in speed, said Mark Reid of the Harvard-Smithsonian Center for Astrophysics, increases the Milky Way's mass by 50 percent, bringing it even with the Andromeda Galaxy. "No longer will we think of the Milky Way as the little sister of the Andromeda Galaxy in our Local Group family." The larger mass, in turn, means a greater...

There is something strange happening in the core of the Milky Way. A space observatory measuring the energy and distribution of gamma-rays in the cosmos has made an unexpected (and perplexing) discovery. It would seem there is a very high proportion of gamma-ray photons emanating from our galactic core with a very distinctive signature; they have a precise energy of 511 keV (8×10-14 Joules), and there’s a lot of them. So what could possibly be producing these 511 keV gamma-rays? It turns out, 511 keV is a magic number; it is the exact rest mass energy of a positron (the...

Enlarge ImageFresh look.Recent surveys of the Milky Way show it contains a prominent central bar feature (bottom), distinguishing it from other galaxies of the classic spiral variety (top).Credit: (top) NASA/Spitzer Space telescope (bottom) NASA/JPL-Caltech/R. Hurt (SSC/Caltech) The Milky Way Gets a Facelift By Phil BerardelliScienceNOW Daily News03 June 2008Forget what you thought the Milky Way looked like. The galaxy is far from the simple and elegant spiral-armed structure so often portrayed. New observations, presented today at the 212th meeting of the American Astronomical Society in St. Louis, Missouri, reveal, among other things, that the Milky Way is missing two...

Enlarge ImageYounger than it looks. Astronomers compared radio (left, blue) and x-ray images (red) of this supernova remnant to determine that the explosion had occurred only 100 years before.Credit: NRAO (radio)/Chandra (x-ray) U.S. and British astronomers have located the youngest known remnant of an exploding star in the Milky Way. The discovery might help researchers understand why our galaxy seems to have so few supernovas and where the raw materials of planets and life came from. The Milky Way is a perfectly ordinary spiral galaxy, except for a shortage of supernova activity. These titanic explosions, which mark the deaths...

Sun's Movement Through Milky Way Regularly Sends Comets Hurtling, Coinciding With Mass Life ExtinctionsA large body of scientific evidence now exists that support the hypothesis that a major asteroid or comet impact occurred in the Caribbean region at the boundary of the Cretaceous and Tertiary periods in Earth's geologic history. Such an impact is suspected to be responsible for the mass extinction of many floral and faunal species, including the large dinosaurs, that marked the end of the Cretaceous period. (Credit: Art by Don Davis / Courtesy of NASA) ScienceDaily (May 2, 2008) — The sun's movement through the Milky...

PARIS (AFP) - A black hole slumbering at the centre of our galaxy went into a "feeding frenzy" three centuries ago, the European Space Agency (ESA) said on Tuesday. Located around 26,000 light years from Earth, the black hole, known as Sagittarius A-star (Sgr A*), is a monster with a mass four million times that of the Sun. Japanese astronomers, using ESA's XMM-Newton orbital telescope and US and Japanese X-ray satellites, discovered that clouds of gas brightened and faded in X-ray light when they passed near Sgr A*'s maw, ESA said in a press release. The phenomenon is due to...

A mushroom-shaped hydrogen cloud rearing 1000 light years above the plane of our galaxy is the aftermath of a massive gas cloud that dive-bombed the Milky Way, new computer simulations suggest. The work explains why the cloud is unlike any other found so far. The cloud, called GW 123.4-1.5, was discovered in 1999 by Jayanne English of the University of Manitoba in Winnipeg, Canada, and colleagues, who found it in a radio survey of the galactic plane. Two explanations for its familiar shape were offered at the time – that the mushroom is a bubble of gas blown out by...

The cosmic cloud is heading for us at more than 240km/sA giant cloud of hydrogen gas is racing towards a collision with the Milky Way, astronomers have announced.Smith's Cloud, as it is known, may set off spectacular fireworks when it smacks into our galaxy in 20-40 million years. It contains enough hydrogen to make a million stars like the Sun, say experts, and its leading edge is already hitting gas from our galaxy. When it does hit, the cloud could indeed set off a new burst of star formation in the Milky Way. Details of the work, by a...

CHICAGO (AFP) - Hundreds of rogue black holes may be roaming around the Milky Way waiting to engulf stars and planets that cross their path, US astronomers said Wednesday. The astronomers believe these "intermediate mass" black holes are invisible except in rare circumstances and have been spawned by mergers of black holes within globular clusters -- swarms of stars held together by their mutual gravity. These black holes are unlikely to pose a threat to Earth, but may engulf nebulae, stars and planets that stray into their paths, the researchers said. "These rogue black holes are extremely unlikely to do...

Astronomers have spotted small galaxies near the beginning of time that resemble ancestors of our own galactic home. The tiny galaxies are about one-tenth to one-twentieth the size of the Milky Way and have 40 times fewer stars. Light from the ancient clusters was emitted about 2 billion years after the Big Bang, the theoretical beginning to the universe that occurred about 13.7 billion years ago. So the galaxies are seen as they existed in a very young universe. The galaxies are not the most distant seen by the Hubble Space Telescope, but astronomers consider them to be the best...

June 7, 2007 — The two heaviest stars ever have been discovered in the southern Milky Way galaxy. The double super heavyweights are actually in orbit around each other, and both break the record — 83 times the sun’s mass — for the most massive stars found to date. The heavier of the two weighs in at a whopping 114 "solar masses," while its little brother is 84 solar masses. The discovery was presented June 7 at the meeting of the Canadian Astronomical Society at the Royal Military College of Canada in Kingston, Ontario. The two big bruiser stars, which...

In a cosmic game of pinball, black holes fling high-energy protons into space, where they zigzag around at near light-speeds before smashing into low-energy protons, finds a new study. Then the collisions send bursts of gamma rays flying out from the center of our galaxy, which explains for the first time the mechanism for the high-energy jets first spotted in 2004. This proton-slinging could explain more than this cataclysmic light show deep in our galaxy. The scientists suggest other black holes in the universe could rely on the pinball mechanism to produce enormous jets of light. “Our galaxy's central supermassive...

This false-color composite of the triple quasar system was made using a combination of Keck Observatory's and the European Very Large Telescope's visible and infrared data. S. G. Djorgovski and colleagues, Caltech, and EPFLOf all the known objects known in the universe, quasars probably deserves the most superlatives. These blazing cosmic beacons pack the energy of an entire galaxy’s worth of stars into a volume of space the size of our solar system. Until now, astronomers have found about 100,000 of these extraordinary objects, which are fueled by supermassive black holes devouring large clumps of matter. Most quasars are solitary...

CALGARY, ALBERTA--A newly detected stream of stars festoons the northern sky in a sweeping arc that cuts across the entire constellation of Ursa Major (through the Big Dipper), from just above the head of Leo the lion to the constellation Cancer the crab. Although it spans fully 63 degrees (one-third of the northern celestial hemisphere), the star stream escaped notice until now because its individual stars are far too faint to see with the naked eye. Also, they don't jump out as a readily discernible shape or pattern, like a cluster or constellation, amid the surrounding star fields. To snare...

Astronomers have found that a diffuse X-ray glow in our galaxy is not generated by hot gas but rather it's radiating from old stars that have yet to be counted. There could be roughly a billion stars we didn't know about in the Milky Way, they said Wednesday. The discovery, if confirmed, "would have a profound impact on our understanding of the history of our galaxy, from star-formation and supernova rates to stellar evolution," according to a statement released by NASA.

WASHINGTON (Reuters) - The Milky Way is warped -- like a bowl, a saddle or the brim of a fedora hat, depending on when you look -- and a pair of interloping galaxies may be to blame, astronomers said on Monday. Earth is in a fairly non-warped neighborhood, because it lies relatively close to the center of the Milky Way's disk, said Leo Blitz of the University of California, Berkeley. But the far-flung reaches of the galaxy could be caught up in a warp of as much as 20,000 light-years. A light-year is about 6 trillion miles, the distance light...

Astronomers are reporting today that they have moved a notch closer to seeing the unseeable. Using a worldwide array of radio telescopes to obtain the most detailed look yet at the center of the Milky Way, they said they had determined that the diameter of a mysterious fountain of energy there was less than half that of Earth's orbit about the Sun. The result strengthens the case that the energy is generated by a black hole that is gobbling stars and gas, they said. It also leaves astronomers on the verge of seeing the black hole itself as a small...