Tag Archives: spiral galaxy

Spiral galaxies like Milky Way bigger than thought, says CU-Boulder study

Let’s all fist bump: Spiral galaxies like our own Milky Way appear to be much larger and more massive than previously believed, according to a new University of Colorado Boulder study by researchers using the Hubble Space Telescope.

CU-Boulder Professor John Stocke, study leader, said new observations with Hubble’s $70 million Cosmic Origins Spectrograph, or COS, designed by CU-Boulder show that normal spiral galaxies are surrounded by halos of gas that can extend to over 1 million light-years in diameter. The current estimated diameter of the Milky Way, for example, is about 100,000 light-years. One light-year is roughly 6 trillion miles. (more…)

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The Supernova That Cried Wolf

A luminous supernova in a galaxy 67 million light years away from us has finally exploded for good, a UA-led team of astronomers has discovered. This event sheds light on how massive stars end their lives.

Astronomers have announced that a massive star, which they have watched repeatedly mimic a supernova since 2009, has finally exploded for real.

The report was presented at the American Astronomical Society meeting in Long Beach, Calif. by Jon Mauerhan of the Steward Observatory at the University of Arizona, in collaboration with Nathan Smith, also of the UA, and Alex Filippenko of the University of California, Berkeley.

The result is of special interest because it provides new critical information on the final death throes of massive stars in the years leading up to their explosion. The work has been accepted for publication in the Monthly Notices of the Royal Astronomical Society. (more…)

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World’s Most Powerful Digital Camera Begins Hunt for Dark Energy

Eight billion years ago, rays of light from distant galaxies began their long journey to Earth. That ancient starlight has now found its way to a mountaintop in Chile, where the newly constructed Dark Energy Camera, the most powerful sky-mapping machine ever created, has captured and recorded it for the first time.

That light may hold within it the answer to one of the biggest mysteries in physics: Why the expansion of the universe is speeding up. (more…)

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Astronomers Using the Hubble Space Telescope Report the Earliest Spiral Galaxy Ever Seen

Astronomers have witnessed for the first time a spiral galaxy in the early universe, billions of years before many other spiral galaxies formed. In findings reported July 19 in the journal Nature, the astronomers said they discovered it while using the Hubble Space Telescope to take pictures of about 300 very distant galaxies in the early universe and to study their properties. This distant spiral galaxy is being observed as it existed roughly three billion years after the Big Bang, and light from this part of the universe has been traveling to Earth for about 10.7 billion years.

“As you go back in time to the early universe, galaxies look really strange, clumpy and irregular, not symmetric,” said Alice Shapley, a UCLA associate professor of physics and astronomy, and co-author of the study. “The vast majority of old galaxies look like train wrecks. Our first thought was, why is this one so different, and so beautiful?” (more…)

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Newly Found Dwarf Galaxies Could Help Reveal the Nature of Dark Matter

ANN ARBOR, Mich.— In work that could help advance astronomers’ understanding of dark matter, University of Michigan researchers have discovered two additional dwarf galaxies that appear to be satellites of Andromeda, the closest spiral galaxy to Earth.

Eric Bell, an associate professor in astronomy, and Colin Slater, an astronomy Ph.D. student, found Andromeda XXVIII and XXIX—that’s 28 and 29. They did it by using a tested star-counting technique on the newest data from the Sloan Digital Sky Survey, which has mapped more than a third of the night sky. They also used follow-up data from the Gemini North Telescope in Hawaii. (more…)

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Astronomers Identify Thick Disc of Older Stars in Nearby Andromeda Galaxy

An international team of astronomers has identified for the first time a thick stellar disc in the Andromeda galaxy, the nearest large spiral galaxy to our own Milky Way. 

The discovery of the thick disc, a major result from a five-year investigation, will help astronomers better understand the processes involved in the formation and evolution of large spiral galaxies like ours, according to the team, which includes UCLA research astronomer Michael Rich and colleagues from Europe and Australia.  (more…)

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