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Citizen Scientists Reveal a Bubbly Milky Way

A team of volunteers has pored over observations from NASA's Spitzer Space Telescope and discovered more than 5,000 "bubbles" in the disk of our Milky Way galaxy. Young, hot stars blow these bubbles into surrounding gas and dust, indicating areas of brand new star formation.
Upwards of 35,000 "citizen scientists" sifted through the Spitzer infrared data as part of the online Milky Way Project to find these telltale bubbles. The volunteers have turned up 10 times as many bubbles as previous surveys so far.

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Planck All-Sky Images Show Cold Gas and Strange Haze

New images from the Planck mission show previously undiscovered islands of star formation and a mysterious haze of microwave emissions in our Milky Way galaxy. The views give scientists new treasures to mine and take them closer to understanding the secrets of our galaxy.
Planck is a European Space Agency mission with significant NASA participation.

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Pitt Astronomers Determine Colour of the Milky Way Galaxy

A team of astronomers in Pitt's Kenneth P. Dietrich School of Arts and Sciences announced today the most accurate determination yet of the colour of the (aptly named) Milky Way Galaxy: "a very pure white, almost mirroring a fresh spring snowfall." Jeffrey Newman, Pitt professor of physics and astronomy, and Timothy Licquia, a PhD student in physics at Pitt, reported their findings during a presentation at the 219th American Astronomical Society (AAS) Meeting in Austin, Texas.
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Stars Pop Onto the Scene in New WISE Image

pia15256-640.jpg
Credit: NASA/JPL-Caltech/UCLA

A new, large mosaic from NASA's Wide-Field Infrared Survey Explorer (WISE) showcases a vast stretch of cosmic clouds bubbling with new star birth. The region -- a 1,000-square-degree chunk of our Milky Way galaxy -- is home to numerous star-forming clouds, where massive stars have blown out bubbles in the gas and dust.

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New Insight into the Bar in the Center of the Milky Way

Astronomers first recognised almost 80 years ago that the Milky Way Galaxy, around which the sun and its planets orbit, is a huge spiral galaxy. This isnt obvious when you look at the band of starlight across the sky, because we are inside the galaxy: its as if the sun and solar system is a bug on the spoke of a bicycle wheel. But in recent decades astronomers have suspected that the center of our galaxy has an elongated stellar structure, or bar, that is hidden by dust and gas from easy view. Many spiral galaxies in the universe are known to exhibit such a bar through the center bulge, while other spiral galaxies are simple spirals. And astronomers ask, why? In a recent paper Dr. Andrea Kunder, of Cerro Tololo Inter-American Observatory (CTIO) in northern Chile, and a team of colleagues have presented data that demonstrates how this bar is rotating.
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Ancient stars shed light on the prehistory of the Milky Way

Some of the oldest stars in the Milky Way - a kind of stellar fossils in the outer reaches of our galaxy, contain abnormally large amounts of heavy elements like gold, platinum and uranium. Where these large amounts came from has been a mystery for researchers, since they are usually seen in much later generations of stars. Researchers at the Niels Bohr Institute have been studying these ancient stars for several years with ESO's giant telescopes in Chile in order to trace the origin of these heavy elements and with recent observations they have concluded how they could have been formed in the early history of the Milky Way. The results are published in the prestigious Astrophysical Journal Letters.
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Title: The Milky Way and other spiral galaxies
Authors: F. Hammer (1), M. Puech (1), H. Flores (1), Y. B. Yang (1), J. L. Wang (1), S. Fouquet (1) ((1) GEPI, Observatoire de Paris, CNRS, Meudon, France)

Cosmologists have often considered the Milky Way as a typical spiral galaxy, and its properties have considerably influenced the current scheme of galaxy formation. Here we compare the general properties of the Milky Way disk and halo with those of galaxies selected from the SDSS. Assuming the recent measurements of its circular velocity results in the Milky Way being offset by ~2 sigma from the fundamental scaling relations. On the basis of their location in the (M_K, R_d, V_flat) volume, the fraction of SDSS spirals like the MilkyWay is only 1.2% in sharp contrast with M31, which appears to be quite typical. Comparison of the Milky Way with M31 and with other spirals is also discussed to investigate whether or not there is a fundamental discrepancy between their mass assembly histories. Possibly the Milky Way is one of the very few local galaxies that could be a direct descendant of very distant, z=2-3 galaxies, thanks to its quiescent history since thick disk formation.

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G75.30+1.32
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Title: Trigonometric Parallaxes of Massive Star-Forming Regions. IX. The Outer Arm in the First Quadrant
Authors: A. Sanna, M. J. Reid, T. M. Dame, K. M. Menten, A. Brunthaler, L. Moscadelli, X. W. Zheng, Y. Xu

We report a trigonometric parallax measurement with the Very Long Baseline Array for the water maser in the distant high-mass star-forming region G75.30+1.32. This source has a heliocentric distance of 9.250.45 kpc, which places it in the Outer arm in the first Galactic quadrant. It lies 200 pc above the Galactic plane and is associated with a substantial HI enhancement at the border of a large molecular cloud. At a Galactocentric radius of 10.7 kpc, G75.30+1.32 is in a region of the Galaxy where the disk is significantly warped toward the North Galactic Pole. While the star-forming region has an instantaneous Galactic orbit that is nearly circular, it displays a significant motion of 18 km/s toward the Galactic plane. The present results, when combined with two previous maser studies in the Outer arm, yield a pitch angle of about 12 degrees for a large section of the arm extending from the first quadrant to the third.

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Milky Way's Spiral Shape May Result from a Smaller Galaxy's Impact

The lovely, familiar swirl of the Milky Way, with its symmetric spiral arms winding outward from a central bulge, may be scars from a smaller galaxy punching above its weight. A new computer re-enactment of billions of years of galactic evolution suggests that the Milky Way owes much of its current shape to interactions with a nearby dwarf galaxy.
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Multiple dwarf strikes gave Milky Way its spirals

A dwarf galaxy called Sagittarius can be credited with giving the Milky Way its signature spiral arms.
Sagittarius struck our galaxy some 1.9 billion years ago. It then looped over the galactic "north pole" and struck again about 900 million years ago. It is heading back right now, on course for a third clash in 10 million years or so.

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