• Scientists read a galaxy's entrails

    ESO

    The galaxy Centaurus A (NGC 5128) is pictured in this image, taken with by the Wide Field Imager attached to the MPG/ESO 2.2-meter telescope at the European Southern Observatory's La Silla Observatory in Chile. With a total exposure time of more than 50 hours, this could be deepest view of Centaurus A ever created.

    By Alan Boyle, Science Editor, NBC News




    Astronomers are taking a long, deep look at one of the best-known galaxies beyond our own Milky Way, to learn more about what happened when it gobbled up another agglomeration of stars that got too close.

    The entrails of the gobbled galaxy are prominent in this view of Centaurus A, a galaxy about 12 million light-years away in the constellation Centaurus. The bright haze of stars is the typical signature of an elliptical galaxy, but the dark, swirling band of dust around the center is a tip-off that the "A" in Centaurus A stands for "atypical."

    Scientists believe the band represents the dusty leftovers of the galaxy that has been consumed in a gravitationally driven merger. Flashes of fresh hot stars can be seen along the edges of the band. It's thought that an energetic black hole, 100 million times as massive as our sun, is blasting out strong radio emissions from the center of the haze.

    Much of this has been seen before, in previous images of Centaurus A. But today's image, captured by the Wide Field Imager on the European Southern Observatory's MPG/ESO 2.2-meter telescope in Chile, reveals extra details. That's because the camera exposure lasted for more than 50 hours, making this one of the deepest views of Centaurus A ever produced.

    One reddish filament of material is visible above the left edge of the dark band. A fainter filament can be made out near the upper left corner of the picture. These filaments, hotbeds for infant stars, appear to line up with radio-emitting jets that are being spewed out from the central black hole. Such features can help astronomers reconstruct how Centaurus A gobbled a galaxy in the first place, and how the remains are being digested. Further studies, involving ESO's ALMA Observatory, will shed additional light on the scene.

    A video from the European Southern Observatory zooms in on telescope views of Centaurus A, a giant cannibal galaxy.

    More about the gobbling galaxy:

    Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

  • DMITRY KOSTYUKOV / AFP - Getty Images

    An armoured vehicle of US Marines from 1st Battalion 8th, Bravo is seen in front of The Milky Way Galaxy (R) during an operation not far from Shir Chazay in Musa Qala district of Helmand province on Jan. 23. A 140,000-strong force of NATO-led international troops stationed in Afghanistan currently fighting Taliban-led insurgency is now entering its tenth year.

    Stars shine on a clear night in Afghanistan

    By John Makely, NBC News

    Just a tremendous image.

  • NASA / ESA / STScI / Aura

    This Hubble Heritage image shows the spiral galaxy NGC 3982, about 68 million light-years away in the constellation Ursa Major.

    Pinwheel spins with starbirth

    It's hard to imagine a more glorious galaxy than NGC 3982, a face-on spiral that's swirling like a pinwheel 68 million light-years away in the northern constellation Ursa Major. It's a classic target for high-powered telescopes. This picture of the galaxy, released today by the Hubble Heritage team, was assembled from near-infrared and visible-light data captured by the Hubble Space Telescope's Wide Field Planetary Camera 2 between 2000 and 2009.

    The colors have been adjusted to emphasize star-forming regions, rich in hydrogen gas (in pink), as well as hot young stars (in blue). Older stars are concentrated in the galaxy's white-yellow nucleus. This earlier rendering from Hubble shows the pinwheel in natural colors.

    NGC 3982 is more than just a pretty face: Observations of a special kind of star inside the galaxy, known as a Cepheid variable, were used to fine-tune astronomers' best estimates of the Hubble constant -- a number that describes the universe's expansion rate. For what it's worth, the current value of the Hubble constant is judged to be somewhere around 73 kilometers per second per megaparsec. But don't worry: There won't be a quiz.

    More about galaxies, cosmology and Hubble:

    Connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. You can also check out "The Case for Pluto," Alan's book about the controversial dwarf planet and the search for new worlds.