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<title> APOD: 2002 October 17 - Centaurus A: Young Blue Star Stream

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<h1> Astronomy Picture of the Day </h1>

<a href="archivepix.html">Discover the cosmos!</a>

Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2002 October 17

<IMG SRC="image/0210/cena_peng_c1.jpg"

alt="See Explanation. Clicking on the picture will download

the highest resolution version available." width="640" height="498"></a>

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Centaurus A: Young Blue Star Stream

Credit:

E. Peng and H. Ford (<a href="http://www.pha.jhu.edu/">JHU</a>),

K. Freeman (<a href="http://www.anu.edu.au/">ANU</a>),

R. White (<a href="http://www.stsci.edu">STScI</a>),

<a href="http://www.ctio.noao.edu/">CTIO</a>,

<a href="http://www.noao.edu/">NOAO</a>,

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Explanation:

Almost lost in this cosmic jumble of stars, gas and dust is a faint but

<a href="image/0210/cena_peng_arrows.jpg">definite blue arc</a> -- a

stream of young stars whose formation was

probably triggered as a small dwarf galaxy was

<a href="ap020502.html">torn apart</a>

approaching the giant elliptical galaxy

<a href="http://oposite.stsci.edu/pubinfo/pr/1998/14/

astrofile.html">Centaurus A</a>.

The 2,000 light-year long arc is revealed in the upper right corner of

<a href="http://www.noao.edu/outreach/press/pr02/pr0211.html">this

processed color</a>

digital image, while the dense central region

<a href="ap020421.html">of Centaurus A</a> is near the bottom.

Star clusters that make up the blue arc are likely strung out along the

incoming trajectory of the small galaxy and are estimated to be only

200-400 million years old.

<a href="http://xxx.lanl.gov/abs/astro-ph/0208422">The remarkable result</a>

suggests that astronomers have identified

a spectacular example of a kind of galactic cannibalism in progress,

a process which is believed to contribute to the formation and

<a href="http://gladstone.uoregon.edu/~cturner/p401/

collisions.html">evolution</a>

of large galaxies, including our own

<a href="ap980826.html">Milky Way</a>.

Over time, stars and star clusters in this stream should

eventually disperse <a href="http://sci.esa.int/content/news/

index.cfm?aid=20&cid=660&oid=12503">and merge</a>

with tumultuous <a href="ap020812.html">Centaurus A</a>.

The image data was recorded with the four meter

<a href="http://www.ctio.noao.edu/new/Sky%20Conditions/Webcam/">Blanco

telescope</a> at Cerro Tololo Inter-American Observatory.

Tomorrow's picture: <a href="ap021018.html">perenigricon</a>

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Authors & editors:

<a href="http://antwrp.gsfc.nasa.gov/htmltest/rjn.html">Robert Nemiroff</a>

(<a href="http://www.phy.mtu.edu/">MTU</a>) &

<a href="http://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html"

>Jerry Bonnell</a> (<a href="http://www.usra.edu/">USRA</a>)

NASA Technical Rep.:

Jay Norris.

<a href="lib/about_apod.html#srapply"

>Specific rights apply</a>.

A service of:

<a href="http://lhea.gsfc.nasa.gov/">LHEA</a> at

<a href="http://www.nasa.gov/">NASA</a>/

<a href="http://www.gsfc.nasa.gov/">GSFC</a> &

<a href="http://www.mtu.edu/">Michigan Tech. U.</a>

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