Defining what makes a star “sun-like" is as difficult as defining what makes a planet "Earth-like." A solar twin should have a temperature, mass and spectral type similar to our sun. We also would expect it to be about 4.5 billion years old. However, it is notoriously difficult to measure a star's age so astronomers usually ignore age when deciding if a star counts as "sun-like."
Meet the seven new dwarf galaxies. Yale Univ. astronomers, using a new type of telescope made by stitching together telephoto lenses, recently discovered seven celestial surprises while probing a nearby spiral galaxy. The previously unseen galaxies may yield important insights into dark matter and galaxy evolution, while possibly signaling the discovery of a new class of objects in space.
As anybody who has started a campfire by rubbing sticks knows, friction generates heat. Now, computer modeling by NASA scientists shows that friction could be the key to survival for some distant Earth-sized planets traveling in dangerous orbits. The findings are consistent with observations that Earth-sized planets appear to be very common in other star systems.
Planet Mercury’s unusual metal-rich composition has been a longstanding puzzle in planetary science. According to a study published online in Nature Geoscience, Mercury and other unusually metal-rich objects in the solar system may be relics left behind by collisions in the early solar system that built the other planets.
Scientists analyzing data from NASA’s Cassini mission have firm evidence the ocean inside Saturn's largest moon, Titan, might be as salty as the Earth's Dead Sea. The new results come from a study of gravity and topography data collected during Cassini's repeated flybys of Titan during the past 10 years. The finding may change some scientists' expectations for present-day life on the distant moon.
An observatory run by the Univ. of Utah has found a “hotspot” beneath the Big Dipper emitting a disproportionate number of the highest-energy cosmic rays. The discovery moves physics another step toward identifying the mysterious sources of the most energetic particles in the universe.
Determining the age of stars has long been a challenge for astronomers. Recent experiments by researchers in Belgium show that “baby” stars can be distinguished from “adolescent” stars by measuring the acoustic waves they emit. This is because stars can vibrate due to sound waves bouncing inside, and those waves are detectable through subtle changes in stellar brightness.
The world of astronomy has changed. An astronomer used to have to travel to a remote location and endure long, cold nights, patiently guiding a telescope to collect precious photons of light. Now, a proliferation of online archives allows astronomers to make discoveries from the comfort of their own offices.
The "man in the moon" appeared when meteoroids struck the Earth-facing side of the moon creating large flat seas of basalt that we see as dark areas called maria. But no "face" exists on farside of the moon and now, Penn State Univ. astrophysicists think they know why.
Earlier this year, Lawrence Livermore National Laboratory engineering technical associate Pam Danforth applied 30 years of laser experience to an out-of-this-world problem—bringing new life to the Univ. of California's Lick Observatory Laser Guide Star. The Lick Observatory's Laser Guide Star is vital to astronomers because a natural guide star isn't always near an object they want to observe.
A new study of supermassive black holes at the centers of galaxies has found magnetic fields play an impressive role in the systems’ dynamics. In fact, in dozens of black holes surveyed, the magnetic field strength matched the force produced by the black holes’ powerful gravitational pull, says a team of scientists.
A new NASA panorama looking deep and far into the universe for the first time includes ultraviolet light, which is normally not visible to the human eye. It shows up in the photo as bright baby blue with spinning galaxies, which are about 5 to 10 billion years old. The photo is a composite of more than 800 photos taken by Hubble and shows about 10,000 multi-colored galaxies.
The slopes of a giant Martian volcano, once covered in glacial ice, may have been home to one of the most recent habitable environments yet found on the Red Planet, according to new research led by Brown Univ. geologists. Nearly twice as tall as Mount Everest, Arsia Mons is the third tallest volcano on Mars and one of the largest mountains in the solar system.
Supernovae are incredibly energetic, dynamic events. It’s easy to imagine that they are uncommon, but the universe is a big place and supernovae are actually fairly routine. The problem with observing supernovae is knowing just when and where one is occurring and being able to point a world-class telescope at it in the hours immediately afterward, when precious data about the supernova's progenitor star is available.
Researcher in the U.K. has recently shown that Saturn’s auroras are caused by the same phenomenon which leads to dramatic auroral displays on Earth. The finding originates in stunning new images of Saturn’s auroras as the planet’s magnetic field is battered by charged particles from the Sun.
Using one of the world's largest telescopes, a Lawrence Livermore National Laboratory team and international collaborators have tracked the orbit of a planet at least four times the size of Jupiter. The scientists were able to identify the orbit of the exoplanet, Beta Pictoris b, which sits 63 light-years from our solar system, by using the Gemini Planet Imager's next-generation, high-contrast adaptive optics system.
Carbon-rich planets may be more common than previously thought, according to new research by Yale Univ. astronomers. Some of these planets, all located far beyond Earth’s solar system, could contain vast deposits of graphite or diamonds, and their apparent abundance prompts new questions about the implications of carbon-intense environments for climate, plate tectonics and other geological processes, as well as for life.
An important advance in understanding how clusters of stars like our sun are formed has been made by a team that includes seven astronomers at Penn State Univ. and two at other universities. Using data from NASA's Chandra X-ray Observatory and infrared telescopes, the astronomers have shown that earlier theories about the process that creates star clusters in giant clouds of gas and dust cannot be correct.
Move over, Matrix, astronomers at MIT/Harvard-Smithsonian Center for Astrophysics and the Heidelberg Institute for Theoretical Studies in Germany have done you one better. They have created the first realistic virtual universe using a computer simulation called "Illustris." Illustris can recreate 13 billion years of cosmic evolution in a cube 350 million light-years on a side with unprecedented resolution.
The galaxy known as M87 has a fastball that would be the envy of any baseball pitcher. It has thrown an entire star cluster toward us at more than two million miles per hour. The newly discovered cluster, which astronomers named HVGC-1, is now on a fast journey to nowhere. Its fate: to drift through the void between the galaxies for all time.
Out on the edge of the universe, 75,000 light-years from us, a galaxy known as Segue 1 has some unusual properties: It’s the faintest galaxy ever detected. It’s very small, containing only about 1,000 stars. And it has a rare chemical composition, with vanishingly small amounts of metallic elements present.
Caltech astronomers have taken unprecedented images of the intergalactic medium (IGM)—the diffuse gas that connects galaxies throughout the universe—with the Cosmic Web Imager, an instrument designed and built at Caltech. Until now, the structure of the IGM has mostly been a matter for theoretical speculation. However, with observations from the Cosmic Web Imager, astronomers are obtaining our first 3-D pictures of the IGM.
Brown dwarfs start their lives like stars, as collapsing balls of gas, but they lack the mass to burn nuclear fuel and radiate starlight. A "brown dwarf" star that appears to be the coldest of its kind—as frosty as Earth's North Pole—has been discovered by a Penn State Univ. astronomer to be just 7.2 light-years away, making it the fourth closest system to our Sun. The strange star is as frosty as Earth's North Pole.
What looked at first like an upside-down planet has instead revealed a new method for studying binary star systems, discovered by a Univ. of Washington (UW) student astronomer. Working with UW astronomer Eric Agol, doctoral student Ethan Kruse has confirmed the first “self-lensing” binary star system: one in which the mass of the closer star can be measured by how powerfully it magnifies light from its more distant companion star.
Somewhere out in the cosmos an ordinary galaxy spins, seemingly at slumber. Then all of a sudden, WHAM! A flash of light explodes from the galaxy's center. A star orbiting too close to the event horizon of the galaxy's central supermassive black hole has been torn apart by the force of gravity, heating up its gas and sending out a beacon to the far reaches of the universe.