Universe is expanding faster than expected

Photo Source: Thinkstock Washington: The universe is expanding 5 to 9 per cent faster than thought, astronomers using NASA's Hubble Space Telescope have discovered. "This surprising finding may be an important clue to understanding those mysterious parts of the universe that make up 95 per cent of everything and don't emit light, such as dark energy, dark matter, and dark radiation," said study leader and Nobel Laureate Adam Riess of the Space Telescope Science Institute and The Johns Hopkins University in the US. Researchers made the discovery by refining the universe's current expansion rate to unprecedented accuracy, reducing the uncertainty to only 2.4 per cent. The team made the refinements by developing innovative techniques that improved the precision of distance measurements to faraway galaxies. They looked for galaxies containing both Cepheid stars and Type Ia supernovae. Cepheid stars pulsate at rates that correspond to their true brightness, which can be compared with their apparent brightness as seen from Earth to accurately determine their distance. Type Ia supernovae, another commonly used cosmic yardstick, are exploding stars that flare with the same brightness and are brilliant enough to be seen from relatively longer distances. By measuring about 2,400 Cepheid stars in 19 galaxies and comparing the...

Read More........→July 21, 2016

So you want to know the secrets of the universe...?

The fragments were passed to scientists by teachers from Novosibirsk, who were in the village Emanzhelinka, Chelyabinsk region when the meteorite struck on 15 February. Picture: The Siberian Times  By Kate Baklitskaya: Fragments of the meteorite which exploded over the Urals have revealed their geological identity to Siberian scientists. The main minerals of these samples are silicates: olivine (Mg, Fe) 2SiO4 and orthopyroxene (Mg, Fe) 2Si2O6, it was disclosed. Iron and nickel sulfides (troilite, FeS, heazlewoodite Ni3S2), and native metals Fe and Ni (kamacite, taenite) were found in smaller amounts. In addition scientists found chromite (Fe, Mg) Cr2O4, clinopyroxene (diopside CaMgSi2O6), plagioclase (Ca, Na) Al2Si2O8, as well as glass feldspar composition in the fragments of a meteorite. The analysis was carried out using scanning microscopy and a gas chromatography-mass spectrometer at the V S Sobolev Institute of Geology and Mineralogy, part of the Siberian Branch of the Russian Academy of Sciences.  Experts from the Central Siberian Geological Museum Institute were also involved.  Such preliminary data is important for the reconstruction of the early stages of the solar system: it is believed that meteorites are similar to the very stuff which, in fact, formed the planets. Pictures: SORAN media centre  The...

Read More........→May 24, 2016

A New Way To See The High-Energy Sky

Credit: HAWC Collaboration University of Maryland (UMD) physicists pioneered development of observatory that has located new high-energy sources in the universe and provided more detail on known sources in first year of full operation. HAWC observations show that a previously known gamma ray source in the Milky Way galaxy, TeV J1930+188, which is probably due to a pulsar wind nebula, is far more complicated than originally thought. Where researchers previously identified a single gamma ray source, HAWC identified several hot spots. The United States and Mexico constructed the High Altitude Water Cherenkov (HAWC) Gamma-ray Observatory to observe some of the most energetic phenomena in the known universe--the aftermath when massive stars die, glowing clouds of electrons around rapidly spinning neutron stars, and supermassive black holes devouring matter and spitting out powerful jets of particles. These violent explosions produce high-energy gamma rays and cosmic rays, which can travel large distances--making it possible to see objects and events far outside our own galaxy. Today, scientists operating HAWC released a new survey of the sky made from the highest energy gamma rays ever observed. The new sky map, which uses data collected since the observatory began running at full capacity last March, offers a deeper understanding...

Read More........→April 25, 2016

A Deep Look Into A Single Molecule

Credit: PTB The quantum state of a molecular ion has been measured live and in a non-destructive fashion for the first time. The interaction of thermal energy from the environment with motional degrees of freedom is well known and often referred to as Brownian motion (also thermal motion). But in the case of polar molecules, the internal degrees of freedom - in particular the rotational quantum state - are also influenced by the thermal radiation. So far, the detection of the rotational state was only possible by destroying the molecule. However, a German research group has now demonstrated the first implementation of a non-destructive state detection technique for molecular ions. Piet Schmidt and his colleagues from the QUEST-Institute at the Physikalisch-Technische Bundesanstalt (PTB) observed changes in the rotational state of a trapped and indirectly cooled molecular ion in real time and in situ. This technique enables novel spectroscopy methods with applications ranging from chemistry to tests of fundamental physics. The results are published in the current issue of "Nature". Basic concept of the experiment: MgH+ (orange) and Mg+ (green) are trapped together in a linear ion trap. The two-ion compound is cooled to the motional ground state via the atomic ion. An oscillating dipole force changes the motional state according...

Read More........→February 15, 2016

Superluminous Supernova 20 Times Brighter Than 100 Billion Stars Wows Astronomers

Records are made to be broken, as the expression goes, but rarely are records left so thoroughly in the dust. Stunned astronomers have witnessed a cosmic explosion about 200 times more powerful than a typical supernova--events which already rank amongst the mightiest outbursts in the universe--and more than twice as luminous as the previous record-holding supernova. At its peak intensity, the explosion--called ASASSN-15lh--shone with 570 billion times the brightness of the Sun. If that statistic does not impress, consider that this luminosity level is approximately 20 times the entire output of the 100 billion stars comprising our Milky Way galaxy. The record-breaking blast is thought to be an outstanding example of a "superluminous supernova," a recently discovered, supremely rare variety of explosion unleashed by certain stars when they die. Scientists are frankly at a loss, though, regarding what sorts of stars and stellar scenarios might be responsible for these extreme supernovae. These are pseudo-color images showing the host galaxy before the explosion of ASASSN-15lh taken by the Dark Energy Camera (DECam) [Left], and the supernova by the Las Cumbres Observatory Global Telescope Network (LCOGT) 1-meter telescope network [Right]. As described in a new study published today in Science, ASASSN-15lh Credit: The...

Read More........→January 15, 2016