We’ve Revealed A Galaxy Far, Far Away….
The galaxy was uncovered in radio emission travelling to Earth using CSIRO’s Australian SKA Pathfinder telescope (ASKAP), located at the Murchison Radio-astronomy Observatory (MRO).
The team used a special technique to detect a change in radio waves coming from within the bright centre of the galaxy PKS B1740-517, located near the Ara constellation.
The five-billion-year-old radio emission was stamped with the ‘imprint’ of hydrogen gas it had travelled through on its way to Earth.
The gas absorbs some of the emission, creating a tiny dip in the signal. “At many observatories, this dip would have been hidden by background radio noise, but our site is so radio quiet it stood out clearly,” Dr Allison said.
Rings And Loops In The Stars: Planck’s Stunning New Images
Credit: M. Peel / JCBA / Planck / ESA
A ring of dust 200 light years across and a loop covering a third of the sky: two of the results in a new map from the Planck satellite. Dr Mike Peel and Dr Paddy Leahy of the Jodrell Bank Centre for Astrophysics (JCBA) presented the images today at the National Astronomy Meeting (NAM 2015) at Venue Cymru, Llandudno, Wales.
The European Space Agency (ESA) Planck satellite, launched in 2009 to study the ancient light of the Big Bang, has also given us maps of our own Galaxy, the Milky Way, in microwaves (radiation at cm- to mm-wavelengths). Microwaves are generated by electrons spiralling in the Galaxy’s magnetic field at nearly the speed of light (the synchrotron process); by collisions in interstellar plasma, by thermal vibration of interstellar dust grains, and by “anomalous” microwave emission (AME), which may be from spinning dust grains.
The relative strength of these processes changes with wavelength, and are separated using multi-wavelength measurements from Planck, from NASA’s WMAP satellite, and from ground-based radio telescopes, giving maps of each component.
Astronomers ‘Unscramble’ Einstein Ring To Reveal Most Detailed View Ever Of Star Formation In The Distant Universe
Credit: ALMA (NRAO/ESO/NAOJ)/Y. Tamura (The University of Tokyo)/Mark Swinbank (Durham University)
ALMA’s Long Baseline Campaign produced spectacular images of the distant, gravitationally lensed galaxy called HATLAS J090311.6+003906, otherwise known as SDP.81. New analyses of these images reveal details never before seen in a galaxy so remote, including phenomenally massive yet concentrated clumps of star-forming material.
The ALMA observations of SDP.81, made at the end of 2014, were enabled by a cosmic effect known as gravitational lensing. A large galaxy nestled between SDP.81 and ALMA is acting as a lens, magnifying the more distant galaxy’s light and warping it into a near-perfect example of a phenomenon known as an Einstein Ring.
In the months following these observations, at least seven groups of scientists have independently analyzed the ALMA data on SDP.81. This flurry of research papers has divulged unprecedented information about the galaxy, including details about its structure, contents, motion, and other physical characteristics.
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Nearby “Dwarf” Galaxy Is Home To Luminous Star Cluster
The NGC 5253 galaxy as seen through the Hubble Space Telescope
A team of Tel Aviv University and UCLA astronomers have discovered a remarkable cluster of more than a million young stars are forming in a hot, dusty cloud of molecular gases in a tiny galaxy very near our own.
The star cluster is buried within a massive gas cloud dubbed “Cloud D” in the NGC 5253 dwarf galaxy, and, although it’s a billion times brighter than our sun, is barely visible, hidden by its own hot gases and dust. The star cluster contains more than 7,000 massive “O” stars: the most brilliant stars extant, each a million times more luminous than our sun.
“Cloud D is an incredibly efficient star and soot factory,” says Prof. Sara Beck of TAU’s Department of Astronomy and Astrophysics and co-author of the research, recently published in Nature. “This cloud has created a huge cluster of stars, and the stars have created an unprecedented amount of dust.”
Sunset Jets On Rosetta’s Comet
ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
When night falls on Rosetta’s comet 67P/Churyumov-Gerasimenko, the bizarrely shaped body remains active. This can be seen in new images of the Ma’at region located on the comet’s “head” captured by OSIRIS, the scientific imaging system on board the Rosetta spacecraft. They were taken approximately half an hour after the Sun had set over the region and show clearly distinguishable jets of dust escaping into space. Researchers from the OSIRIS team believe that the increasing heating-up of the comet is responsible for the newly observed phenomenon.
“Only recently have we begun to observe dust jets persisting even after sunset”, says OSIRIS Principal Investigator Holger Sierks from the Max Planck Institute for Solar System Research (MPS) in Germany. In the past months, the comet’s activity originated from illuminated areas on the day side. As soon as the Sun set, these jets subsided and did not re-awake until after the next sunrise. An exception poses an image from 12 March, 2015 showing the onset of a dust jet on the brink of dawn.
The Moon Photobombs Uranus Live
Observers in eastern Australia, all of New Zealand, and parts of the South Pacific will see the planet Uranus pass behind the waning crescent Moon in the early morning of June 12, 2015. The precise timing of the event depends on your location. In Adelaide, Australia, Uranus passes behind the Moon at 18:49 UT, just after moonrise, and emerges from the dark part of the crescent Moon’s face at 19:57 UT. In Sydney the occultation begins at 19:01 UT and ends at 20:17 UT.
Observers in the rest of the world will see Uranus close to the crescent Moon in the eastern pre-dawn sky. This presents an excellent opportunity to spot this distant ice giant with a pair of binoculars or a small telescope. Slooh will be presenting live views of the event courtesy of our Australian feed partners. Join us to watch live views of the Solar System in motion!
Exiled Stars Explode Far From Home
Artist’s concept. Image by Dr. Alex H Parker, NASA and the SDSS
Sharp images obtained by the Hubble Space Telescope confirm that three supernovae discovered several years ago exploded in the dark emptiness of intergalactic space, having been flung from their home galaxies millions or billions of years earlier.
Most supernovae are found inside galaxies containing hundreds of billions of stars, one of which might explode per century per galaxy.
These lonely supernovae, however, were found between galaxies in three large clusters of several thousand galaxies each. The stars’ nearest neighbors were probably 300 light years away, nearly 100 times farther than our sun’s nearest stellar neighbor, Proxima Centauri, 4.24 light years distant.
uch rare solitary supernovae provide an important clue to what exists in the vast empty spaces between galaxies, and can help astronomers understand how galaxy clusters formed and evolved throughout the history of the universe.
Hubble Video Shows Shock Collision Inside Black Hole Jet
Credit: NASA, ESA, and E. Meyer (STScI)
When you’re blasting though space at more than 98 percent of the speed of light, you may need driver’s insurance. Astronomers have discovered for the first time a rear-end collision between two high-speed knots of ejected matter from a super-massive black hole. This discovery was made while piecing together a time-lapse movie of a plasma jet blasted from a supermassive black hole inside a galaxy located 260 million light-years from Earth.
he finding offers new insights into the behavior of “light-saber-like” jets that are so energized that they appear to zoom out of black holes at speeds several times the speed of light. This “superluminal” motion is an optical illusion due to the very fast real speed of the plasma, which is close to the universal maximum of the speed of light.
Such extragalactic jets are not well understood. They appear to transport energetic plasma in a confined beam from the central black hole of the host galaxy. The new analysis suggests that shocks produced by collisions within the jet further accelerate particles and brighten the regions of colliding material.
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Dawn Spirals Closer To Ceres, Returns A New View
Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
A new view of Ceres, taken by NASA’s Dawn spacecraft on May 23, shows finer detail is becoming visible on the dwarf planet. The spacecraft snapped the image at a distance of 3,200 miles (5,100 kilometers) with a resolution of 1,600 feet (480 meters) per pixel. The image is part of a sequence taken for navigational purposes.
After transmitting these images to Earth on May 23, Dawn resumed ion-thrusting toward its second mapping orbit. On June 3, Dawn will enter this orbit and spend the rest of the month observing Ceres from 2,700 miles (4,400 kilometers) above the surface. Each orbit during this time will be about three days, allowing the spacecraft to conduct an intensive study of Ceres.
Hubble Finds Two Chaotically Tumbling Pluto Moons
Artist’s illustrations. Credit: NASA, ESA, M. Showalter (SETI Institute), and G. Bacon (STScI)
If you lived on one of Pluto’s moons Nix or Hydra, you’d have a hard time setting your alarm clock. That’s because you could not know for sure when, or even in which direction, the sun would rise.
A comprehensive analysis of all available Hubble Space Telescope data shows that two of Pluto’s moons, Nix and Hydra, are wobbling unpredictably. Scientists believe the other two small moons, Kerberos and Styx, are likely in a similar situation, pending further study.
“Hubble has provided a new view of Pluto and its moons revealing a cosmic dance with a chaotic rhythm,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate in Washington, D.C. “When the New Horizons spacecraft flies through the Pluto system in July we’ll get a chance to see what these moons look like up close and personal.”
Why the chaos? Because the moons are embedded inside a dynamically shifting gravitational field caused by the system’s two central bodies, Pluto and Charon, whirling about each other. The variable gravitational field induces torques that send the smaller moons tumbling in unpredictable ways. This torque is strengthened by the fact the moons are football shaped rather than spherical.
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