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Long before the Bible's tale of Jonah being swallowed by a whale, a small wannabe star has emerged intact after being engulfed by a neighboring giant star, scientists say. The victim was a brown dwarf, a failed star too small to sustain the nuclear reactions that ignites regular stars. The purpetrator was a red giant, an ancient star that once resembled our Sun but which puffed up to enormous size after its hydrogen fuel was depleted. The red giant has since expelled most of its gas into space and transformed into a dense, Earth-sized star called a white dwarfs. Using...

Line up Mercury, Venus, Earth and Mars according to their distance from the sun and you'll see their size distribution is close to symmetrical, with the two largest planets between the two smallest. That would be no coincidence -- if the pattern emerged from a debris ring around the sun. Brad Hansen of the University of California, Los Angeles, built a numerical simulation to explore how a ring of rocky material in the early solar system could have evolved into the planets. He found that two larger planets typically form near the inner and outer edges of the ring, corresponding...

This is an artist's concept of a hypothetical 10-million-year-old star system. The bright blur at the center is a star much like our sun. The other orb in the image is a gas-giant planet like Jupiter. Wisps of white throughout the image represent traces of gas. Astronomers using NASA's Spitzer Space Telescope have found evidence showing that gas-giant planets either form within the first 10 million years of a sun-like star's life, or not at all. The lifespan for sun-like stars is about 10 billion years. The scientists came to this conclusion after searching for traces of gas around...

University of Arizona scientists have uncovered a curious case of missing asteroids. The main asteroid belt is a zone containing millions of rocky objects between the orbits of Mars and Jupiter. The scientists find that there ought to be more asteroids there than researchers observe. The missing asteroids may be evidence of an event that took place about 4 billion years ago, when the solar system's giant planets migrated to their present locations. UA planetary sciences graduate student David A. Minton and UA planetary sciences professor Renu Malhotra say missing asteroids is an important piece of evidence to support an...

Using the new Combined Array for Research in Millimeter Astronomy (CARMA), Eisner and his colleagues observed more than 250 stars in Orion's central region and found that less than 8% had dust disks thought massive enough to create a Jupiter. The radiation from hot, massive stars in the cluster probably clears out a lot of surrounding material and keeps high-mass disks from forming, explains co-author John Carpenter (Caltech). In all, about 10% of the observed stars emit radiation associated with warm dust disks. The results agree almost perfectly with findings by Geoff Marcy (UC Berkeley) and his colleagues, who conclude...

In our Solar System, four planets stand out for their sheer mass and size. Jupiter, Saturn, Uranus and Neptune indeed qualify as "giant planets" because they are larger than any terrestrial planet and much more massive than all other objects in the Solar System, except the Sun, put together. According to Dr. Guillot, "the giant planets, because of their gravitational might, they have played a key role in the formation of the Solar System, tossing around many objects in the system, preventing the formation of a planet in what is now the asteroid belt, and directly leading to the formation...

A star mystery solved? These newfound stars could help solve the so-called "photon underproduction crisis," which suggests that an extraordinary amount of ultraviolet light appears to be missing from the universe. The intergalactic stars could also help address what is known as the "missing baryon problem." Baryons are a class of subatomic particles that includes the protons and neutrons that make up the hearts of atoms inside normal matter. Theories of the formation and evolution of the universe predict there should be far more baryons than scientists currently see. The baryons that astronomers have accounted for in the local cosmic...

U.S. scientists studying "runaway" stars tossed out of our galaxy at great velocities say they've confirmed the same thing can happen to planets. The first runaway star was discovered seven years ago, heading out of the Milky Way at 1.5 million mph, and new research says planets must be doing the same thing -- at speeds up to 30 million mph, the Harvard-Smithsonian Center for Astrophysics reported Thursday. "These warp-speed planets would be some of the fastest objects in our galaxy," astrophysicist Avi Loeb said. "If you lived on one of them, you'd be in for a wild ride from...

An international team of astronomers claim to have found free-floating "planets" which do not seem to orbit a star.Writing in Nature, they say they have found 10 Jupiter-sized objects which they could not connect to any solar system. They also believe such objects could be as common as stars are throughout the Milky Way. The objects revealed themselves by bending the light of more distant stars, an effect called "gravitational microlensing".Objects of large enough mass can bend light, as Albert Einstein predicted. If a large object passes in front of a more distant background star, it may act as a...

Neptune's own existence was a puzzle until recently. The dusty cloud that gave birth to the planets probably thinned out further from the sun. With building material so scarce, it is hard to understand how Uranus and Neptune, the two outermost planets, managed to get so big. But what if they formed closer in? In 2005, a team of scientists proposed that the giant planets shifted positions in an early upheaval (New Scientist, 25 November 2006, p 40). In this scenario, Uranus and Neptune formed much closer to the sun and migrated outwards, possibly swapping places in the process. That...

The University of Arizona Lunar and Planetary Laboratory is launching its Fall 2009 Evening Lecture Series with talks on wandering solar system planets and searches for hazardous asteroids from Mount Lemmon... Planetary sciences professor Renu Malhotra will speak on "Migrating Planets" on Tuesday, Sept. 15. [whoops] Did the solar system always look the way it is now? New studies by Malhotra and others find that the outer planets -- Jupiter, Saturn, Uranus and Neptune -- were more tightly clustered in the early solar system, then moved away from each other. Malhotra's models show that as the solar system evolved, Jupiter...

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...

For scientists who spend time thinking about how planets form, life would be simpler if gas giants like Jupiter and Saturn didn’t exist. According to the standard model of planet formation, called "core accretion," planets form over millions of years as enormous blocks of rock and ice smash together to form planetary embryos, called "protoplanets," and eventually full-fledged planets. Most scientists agree that core accretion is how terrestrial planets such as Earth and Mars were created, but the model can’t convincingly explain how gas giant planets like Jupiter and Saturn came to be. One major problem is that developing gas...

At my age, I really should have expected this to happen. All of a sudden I'm seeing lots of little clues that the 1980s are making something of a nostalgic comeback. High school kids I speak to as part of my job have started wearing thin ties and studded belts, and I thoroughly approve of their newly spiked and teased hairstyles. The other day I saw a pair of plastic sandals (remember Jellies?) in a store window and heard Bon Jovi playing on a "classic rock" station. That's right; I'm a golden oldie. Take, for instance, the fact that when...

NASA's Spitzer Space Telescope has found a dusty ring of material orbiting nearby Vega which was probably the result of a series of protoplanets smashing into each other. Vega is the fifth brightest star in the sky, located only 25 light-years away in the constellation of Lyra. This dust is constantly being blown out by Vega's intense radiation, so it's unlikely that the star has had this much dust for its entire lifetime. Instead, this ring must have been formed recently, perhaps when a Pluto-sized object was pulverized within the last million years or so.

If you can make sense of it, here's the article: Stellar encounters as the origin of distant Solar System objects in highly eccentric orbits SCOTT J. KENYON AND BENJAMIN C. BROMLEY The Kuiper belt extends from the orbit of Neptune at 30 AU to an abrupt outer edge about 50 AU from the Sun. Beyond the edge is a sparse population of objects with large orbital eccentricities. Neptune shapes the dynamics of most Kuiper belt objects, but the recently discovered planet 2003 VB12 (Sedna) has an eccentric orbit with a perihelion distance of 70 AU, far beyond Neptune's gravitational influence....

Some Stars Capture Rogue Planets by Staff Writers Boston MA (SPX) Apr 20, 2012 New research suggests that billions of stars in our galaxy have captured rogue planets that once roamed interstellar space. The nomad worlds, which were kicked out of the star systems in which they formed, occasionally find a new home with a different sun. This finding could explain the existence of some planets that orbit surprisingly far from their stars, and even the existence of a double-planet system. "Stars trade planets just like baseball teams trade players," said Hagai Perets of the Harvard-Smithsonian Center for Astrophysics. The...

Free-floating rogue planets are intriguing objects. These planet-sized bodies adrift in interstellar space were predicted to exist in 1998, and since 2011 several orphan worlds have finally been detected. The leading theory on how these nomadic planets came to exist is that they were they ejected from their parent star system. But new research shows that there are places in interstellar space that might have the right conditions to form planets — with no parent star required. Astronomers from Sweden and Finland have found tiny, round, cold clouds in space that may allow planets to form within, all on their...

Astronomers have discovered a potential "rogue" alien planet wandering alone just 100 light-years from Earth, suggesting that such starless worlds may be extremely common across the galaxy. The free-floating object, called CFBDSIR2149, is likely a gas giant planet four to seven times more massive than Jupiter, scientists say in a new study unveiled Wednesday. The planet cruises unbound through space relatively close to Earth (in astronomical terms), perhaps after being booted from its own solar system. "If this little object is a planet that has been ejected from its native system, it conjures up the striking image of orphaned worlds,...

Astronomers used ESO's Very Large Telescope and the Canada-France-Hawaii Telescope to find CFBDSIR2149, a free-floating planet with the mass of Jupiter that seems to wander through space without orbiting around a star like most planets we know do. In addition, the planet is actually relatively close to our solar system, only 100 light-years away, and offers scientists a more intimate setting to study a planet and its atmosphere. This isn't the first time that a free-floating object has been found in space, but the previous discoveries haven't provided scientists with enough information to label the body as a planet. Instead,...