http://phys.org/ en-us Phys.org provides the latest news from Harvard-Smithsonian Center for Astrophysics (Phys.org) —Detecting alien worlds presents a significant challenge since they are small, faint, and close to their stars. The two most prolific techniques for finding exoplanets are radial velocity (looking for wobbling stars) and transits (looking for dimming stars). A team at Tel Aviv University and the Harvard-Smithsonian Center for Astrophysics (CfA) has just discovered an exoplanet using a new method that relies on Einstein's special theory of relativity. http://phys.org/news287652362.html Space & Earth Mon, 13 May 2013 08:50:01 EST news287652362 (Phys.org) —In the spring of the year 1006, one thousand and seven years ago this April, observers in China, Egypt, Iraq, Japan, Switzerland (and perhaps North America) reported seeing what might be the brightest stellar event in recorded history: a supernova ("SN1006") that was relatively close to Earth, only about seven thousand light-years away. It was reportedly so bright that it cast shadows at night. In 1965, radio astronomers identified the residue of this event, a so-called supernovae remnant, in the form of a sixty light-year diameter shell of glowing gas. Current models of the cataclysm find that it resulted when two white dwarf stars (each being a late stage of a star's life) merged together. http://phys.org/news285836945.html Space & Earth Mon, 22 Apr 2013 08:11:27 EST news285836945 (Phys.org) —At some stage after its birth in the big bang, the universe began to make galaxies. No one knows exactly when, or how, this occurred. For that matter, astronomers do not know how the lineages of our own Milky Way galaxy and its stars trace back to those first galaxies and their first stars, but astronomers have been working hard to find out. The Hubble Space Telescope announced in 1996 that it had stared at apparently dark sky for ten days at optical wavelengths, long enough to acquire a picture of the very distant universe. The resultant image, the Hubble Deep Field (HDF), reveals galaxies that are so far away that they existed when the universe was less than about 5% of its present age of 14 billion years. Since 1996 astronomers have been working to understand exactly what kinds of galaxies these remote objects are, and whether they bear any resemblance to our own Milky Way galaxy, either as it is now, or as it was when it was younger. http://phys.org/news284973531.html Space & Earth Fri, 12 Apr 2013 08:19:08 EST news284973531 Collisions between galaxies are common. Indeed, most galaxies have probably been involved in one or more encounters during their lifetimes. One example is our own Milky Way, which is bound by gravity to the Andromeda galaxy, our neighbor, and towards which we are approaching at a speed of about 50 kilometers per second, perhaps to meet in another billion years or so. Galaxy-galaxy interactions are thought to stimulate vigorous star formation because the encounters somehow induce the interstellar gas to condense into stars. These stimulated starbursts in turn light up the galaxies, especially at infrared wavelengths, making some systems hundreds or even thousands of times brighter than the Milky Way while they are active. Many of the massive stars that are produced become supernovae whose explosive deaths enrich the environment with carbon, oxygen, and all the other elements that are essential for life. Interacting galaxies are important not only in shedding light on how galaxies evolve, form stars, and seed the interstellar medium, but because they can be very bright and seen across cosmological distances. http://phys.org/news284709766.html Space & Earth Tue, 09 Apr 2013 07:02:56 EST news284709766 (Phys.org) —Galaxies today come very roughly in two types: reddish, elliptically shaped collections of older stars, and bluer, spiral shaped objects dominated by young stars. The conventional wisdom is that the two types are related to one another, ellipticals representing an older, more evolved stage of galaxies. Astronomers have discovered during the past decade that these two categories seem also to apply to galaxies in the early universe. In particular, galaxies so distant from us that their light has been traveling for about eleven and one-half billion years, 84% of the age of the universe, also generally fall into these two groups. http://phys.org/news284195672.html Space & Earth Wed, 03 Apr 2013 08:30:01 EST news284195672 (Phys.org) —IRAS 16293-2922B is a very young star – a protostar - perhaps only about ten thousand years old. Slightly smaller in mass than our Sun, it is still deeply embedded in its surrounding natal material, and apparently is even accreting some of that material onto a circumstellar disk that rings the protostar. In the past decade, it has become possible to study such extremely early stages of star formation thanks to submillimeter and infrared telescopes that can peer through the heavy obscuration of dust in the birth clouds. For the first time, astronomers have been able to address some of the key physical processes underway in these early stages of stellar gestation. http://phys.org/news284195718.html Space & Earth Wed, 03 Apr 2013 08:15:27 EST news284195718 (Phys.org) —Spiral galaxies are some of the most beautiful and photogenic residents of the universe. Our own Milky Way is a spiral. Our solar system and Earth reside somewhere near one of its filamentous arms. And nearly 70 percent of the galaxies closest to the Milky Way are spirals. http://phys.org/news284115712.html Space & Earth Tue, 02 Apr 2013 10:02:29 EST news284115712 (Phys.org) —The star Eta Carinae is ready to blow. 170 years ago, this 100-solar-mass object belched out several suns' worth of gas in an eruption that made it the second-brightest star after Sirius. That was just a precursor to the main event, since it will eventually go supernova. http://phys.org/news281896153.html Space & Earth Thu, 07 Mar 2013 16:29:22 EST news281896153 Imagine a sphere more than 2 million miles across - eight times the distance from Earth to the Moon - spinning so fast that its surface is traveling at nearly the speed of light. Such an object exists: the supermassive black hole at the center of the spiral galaxy NGC 1365. http://phys.org/news281190007.html Space & Earth Wed, 27 Feb 2013 13:00:09 EST news281190007 (Phys.org)—Even dying stars could host planets with life—and if such life exists, we might be able to detect it within the next decade. This encouraging result comes from a new theoretical study of Earth-like planets orbiting white dwarf stars. Researchers found that we could detect oxygen in the atmosphere of a white dwarf's planet much more easily than for an Earth-like planet orbiting a Sun-like star. http://phys.org/news281018911.html Space & Earth Mon, 25 Feb 2013 12:48:40 EST news281018911 Using publicly available data from NASA's Kepler space telescope, astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) have found that six percent of red dwarf stars have habitable, Earth-sized planets. Since red dwarfs are the most common stars in our galaxy, the closest Earth-like planet could be just 13 light-years away. http://phys.org/news279373007.html Space & Earth Wed, 06 Feb 2013 11:37:00 EST news279373007 (Phys.org)—The corona of the sun is the hot (over a million kelvin), gaseous outer region of its atmosphere. The corona is threaded by intense magnetic fields that extend upwards from the surface in braids that are twisted and sheared by the convective stirrings of the underlying dense atmosphere. Understanding the corona and its physical processes is essential to the development of a long-range space weather prediction capability. http://phys.org/news279185528.html Space & Earth Mon, 04 Feb 2013 07:50:01 EST news279185528 (Phys.org)—Two years ago, CfA astronomers reported the discovery of giant, twin lobes of gamma-ray emission protruding about 50,000 light-years above and below the plane of our Milky Way galaxy, and centered on the supermassive black hole at our galaxy's core. The scientists argued then that the bubbles were produced either by an eruption from the black hole sometime in the past, or else by a burst of star formation in that vicinity. http://phys.org/news278579111.html Space & Earth Mon, 28 Jan 2013 07:05:26 EST news278579111 (Phys.org)—The Sun's visible surface, or photosphere, is 10,000 degrees Fahrenheit. As you move outward from it, you pass through a tenuous layer of hot, ionized gas or plasma called the corona. The corona is familiar to anyone who has seen a total solar eclipse, since it glimmers ghostly white around the hidden Sun. http://phys.org/news278175811.html Space & Earth Wed, 23 Jan 2013 15:03:39 EST news278175811 (Phys.org)—Our Milky Way is a spiral galaxy—a pinwheel-shaped collection of stars, gas and dust. It has a central bar and two major spiral arms that wrap around its disk. Since we view the Milky Way from the inside, its exact structure is difficult to determine. http://phys.org/news276885831.html Space & Earth Tue, 08 Jan 2013 16:43:57 EST news276885831